tor-webwml.git

1) ## translation metadata

2) # Revision: $Revision$

3) # Translation-Priority: 4-optional
4) 
5) #include "head.wmi" TITLE="Tor: Volunteer" CHARSET="UTF-8"
6) <div id="content" class="clearfix">
7)   <div id="breadcrumbs">

8)     <a href="<page index>">Home &raquo; </a>

9)     <a href="<page getinvolved/volunteer>">Volunteer</a>
10)   </div>

11)   <div id="maincol"> 

12)     <!-- PUT CONTENT AFTER THIS TAG -->
13)     <h1>A few things everyone can do now:</h1>
14)     <ol>
15)     <li>Please consider <a href="<page docs/tor-doc-relay>">running
16)     a relay</a> to help the Tor network grow.</li>

17)     <li>Do you have an Amazon account? Are you willing to spend up to $3 a

18)     month? Then spin up your own Tor <a href="<page
19)     docs/bridges>">bridge</a> in less than 10 minutes with <a

20)     href="https://cloud.torproject.org/">tor cloud</a>!</li>

21)     <li>Tell your friends! Get them to run relays. Get them to run hidden
22)     services. Get them to tell their friends.</li>
23)     <li>If you like Tor's goals, please <a href="<page donate/donate>">take a moment
24)     to donate to support further Tor development</a>. We're also looking
25)     for more sponsors &mdash; if you know any companies, NGOs, agencies,
26)     or other organizations that want anonymity / privacy / communications
27)     security, let them know about us.</li>
28)     <li>We're looking for more <a href="<page about/torusers>">good examples of Tor
29)     users and Tor use cases</a>. If you use Tor for a scenario or purpose not
30)     yet described on that page, and you're comfortable sharing it with us,
31)     we'd love to hear from you.</li>
32)     </ol>

33)     

34)     <a id="Documentation"></a>
35)     <h2><a class="anchor" href="#Documentation">Documentation</a></h2>
36)     <ol>
37)     <li>Help translate the web page and documentation into other
38)     languages. See the <a href="<page getinvolved/translation>">translation
39)     guidelines</a> if you want to help out. We especially need Arabic or
40)     Farsi translations, for the many Tor users in censored areas.</li>
41)     <li>Evaluate and document

42)     <a href="<wiki>doc/TorifyHOWTO">our

43)     list of programs</a> that can be configured to use Tor.</li>
44)     <li>We have a huge list of <a

45)     href="<wiki>doc/SupportPrograms">potentially useful

46)     programs that interface to Tor</a>. Which ones are useful in which
47)     situations? Please help us test them out and document your results.</li>
48)     </ol>

49)     

50)     <a id="Advocacy"></a>
51)     <h2><a class="anchor" href="#Advocacy">Advocacy</a></h2>
52)     <ol>

53)     <li>Create a presentation that can be used for various user group
54) meetings around the world.</li>

55)     <li>Create a video about the positive uses of Tor, what Tor is,
56)     or how to use it.  Some have already started on <a

57)     href="https://media.torproject.org/video/">Tor's Media server</a>,

58)     <a

59)     href="http://www.howcast.com/videos/90601-How-To-Circumvent-an-Internet-Proxy">Howcast</a>,

60)     and <a href="http://www.youtube.com/thetorproject">YouTube</a>.</li> 

61)     <li>Create a poster, or a set of posters, around a theme,

62)     such as "Tor for Freedom!".</li>

63)     <li>Create a t-shirt design that incorporates "Congratulations!
64)     You are using Tor!" in any language.</li>

65)     </ol>

66)     

67)     <a id="opw"></a>

68)     <h2><a class="anchor" href="#opw">Outreach Program for Women</a></h2>

69)     
70)     <p>
71)     Several organisations, including Tor, are taking part in the <a
72)     href="https://live.gnome.org/OutreachProgramForWomen">2013 Outreach Program
73)     for Women</a>. This is a mentoring program similar to <a
74)     href="https://www.google-melange.com/gsoc/homepage/google/gsoc2012">Google
75)     Summer of Code</a> targeted at getting more women involved in open source.
76)     </p>
77)     
78)     <p>

79)     The program runs from January 2 through April 2, 2013. The application
80)     deadline is December 3, 2012 and it is best to start as early as possible
81)     preparing your application. Like GSoC the program involves a stipend so, if
82)     you're a woman interested in fighting surveillance and censorship around
83)     the world then let us know!

84)     </p>
85)     
86)     <p>
87)     To apply...
88)     </p>
89)     
90)     <ol>
91)       <li>Read up on the <a href="https://live.gnome.org/OutreachProgramForWomen">outreach program</a>.</li>
92)       <li>Look over our projects and task ideas below. If nothing there strikes your fancy then feel free to make one of your own.</li>
93)       <li>Join the <a href="https://www.torproject.org/about/contact.html.en#irc">#tor-dev irc channel</a> and introduce yourself!</li>
94)       <li>Contact the maintainer of the project that you're interested in contributing to, and talk with them about how to get started. Maintainers are listed in the table below. Note that you need to submit a patch or contribute in some way before you can apply to the program.</li>
95)       <li><a href="https://live.gnome.org/OutreachProgramForWomen#Send_in_an_Application">Send your application</a> to opw-list@gnome.org. Please be available and responsive throughout the application period so we can work with you on improving it.</li>
96)     </ol>
97)     

98)     <a id="Projects"></a>
99)     <h2><a class="anchor" href="#Projects">Projects</a></h2>

100)     

101)     <p>
102)     Below are a list of Tor related projects we're developing and/or
103)     maintaining. Most discussions happen on IRC so if you're interested in any
104)     of these (or you have a project idea of your own), then please <a

105)     href="<page about/contact>#irc">join us in #tor-dev</a>. Don't be shy
106)     to ask questions, and don't hesitate to ask even if the main contributors
107)     aren't active at that moment.

108)     </p>

109)     

110)     <table id="projects">
111)       <tr>
112)         <th>Name</th>
113)         <th>Category</th>
114)         <th>Language</th>
115)         <th>Activity</th>
116)         <th>Contributors</th>
117)       </tr>

118)       

119)       <tr>
120)         <td><a href="#project-tor">Tor</a></td>
121)         <td>Core</td>
122)         <td>C</td>
123)         <td>Heavy</td>

124)         <td>nickm, arma, Sebastian</td>

125)       </tr>

126)       

127)       <tr class="alt">

128)         <td>*<a href="#project-jtor">JTor</a></td>
129)         <td>Core</td>
130)         <td>Java</td>
131)         <td>None</td>

132)         <td>bleidl</td>

133)       </tr>

134)       

135)       <tr>

136)         <td><a href="#project-tbb">TBB</a></td>
137)         <td>Usability</td>

138)         <td>Sys Admin</td>
139)         <td>Moderate</td>

140)         <td>Erinn</td>

141)       </tr>

142)       

143)       <tr class="alt">

144)         <td><a href="#project-tails">Tails</a></td>

145)         <td>Usability</td>

146)         <td>Sys Admin</td>

147)         <td>Heavy</td>

148)         <td><a href="https://tails.boum.org/">#tails</a></td>

149)       </tr>

150)       

151)       <tr>

152)         <td><a href="#project-torsocks">Torsocks</a></td>
153)         <td>Usability</td>
154)         <td>C</td>

155)         <td>Heavy</td>
156)         <td>ioerror, nickm</td>

157)       </tr>

158)       

159)       <tr class="alt">

160)         <td>*<a href="#project-torouter">Torouter</a></td>
161)         <td>Usability</td>

162)         <td>Sys Admin</td>

163)         <td>Light</td>

164)         <td>ioerror</td>

165)       </tr>

166)       

167)       <tr>

168)         <td><a href="#project-vidalia">Vidalia</a></td>
169)         <td>User Interface</td>
170)         <td>C++, Qt</td>
171)         <td>Light</td>
172)         <td>chiiph</td>
173)       </tr>

174)       

175)       <tr class="alt">

176)         <td><a href="#project-arm">Arm</a></td>
177)         <td>User Interface</td>
178)         <td>Python, Curses</td>

179)         <td>Light</td>

180)         <td>atagar</td>
181)       </tr>

182)       

183)       <tr>

184)         <td><a href="#project-orbot">Orbot</a></td>
185)         <td>User Interface</td>
186)         <td>Java</td>

187)         <td>Moderate</td>

188)         <td>n8fr8, ioerror</td>

189)       </tr>

190)       

191)       <tr class="alt">

192)         <td><a href="#project-torbutton">Torbutton</a></td>
193)         <td>Browser Add-on</td>
194)         <td>Javascript</td>
195)         <td>Moderate</td>
196)         <td>mikeperry</td>
197)       </tr>

198)       

199)       <tr>

200)         <td><a href="#project-torbirdy">TorBirdy</a></td>
201)         <td>Browser Add-on</td>
202)         <td>JavaScript</td>
203)         <td>Heavy</td>
204)         <td>Sukhbir (sukhe), ioerror</td>
205)       </tr>
206)       
207)       <tr class="alt">

208)         <td><a href="#project-obfsproxy">Obfsproxy</a></td>
209)         <td>Client Add-on</td>
210)         <td>C</td>
211)         <td>Moderate</td>
212)         <td>nickm, asn</td>
213)       </tr>

214)       

215)       <tr>

216)         <td>*<a href="#project-thandy">Thandy</a></td>
217)         <td>Updater</td>
218)         <td>Python</td>
219)         <td>Light</td>

220)         <td>chiiph, Erinn, nickm</td>

221)       </tr>

222)       

223)       <tr class="alt">

224)         <td>*<a href="#project-ooni-probe">Ooni Probe</a></td>
225)         <td>Scanner</td>
226)         <td>Python</td>
227)         <td>Moderate</td>

228)         <td>hellais, isis, ioerror</td>

229)       </tr>

230)       

231)       <tr>

232)         <td><a href="#project-shadow">Shadow</a></td>
233)         <td>Experimentation</td>
234)         <td>C, Python</td>
235)         <td>Moderate</td>
236)         <td>robgjansen</td>
237)       </tr>

238)       

239)       <tr class="alt">

240)         <td><a href="#project-torctl">TorCtl</a></td>
241)         <td>Library</td>
242)         <td>Python</td>

243)         <td>None</td>
244)         <td>aagbsn</td>

245)       </tr>

246)       

247)       <tr>

248)         <td>*<a href="#project-stem">Stem</a></td>
249)         <td>Library</td>
250)         <td>Python</td>
251)         <td>Heavy</td>

252)         <td>atagar, neena</td>

253)       </tr>

254)       

255)       <tr class="alt">

256)         <td><a href="#project-metrics">Metrics</a></td>
257)         <td>Client Service</td>
258)         <td>Java</td>
259)         <td>Heavy</td>
260)         <td>karsten</td>
261)       </tr>

262)       

263)       <tr>

264)         <td><a href="#project-atlas">Atlas</a></td>
265)         <td>Client Service</td>
266)         <td>JavaScript</td>
267)         <td>Moderate</td>
268)         <td>hellais</td>
269)       </tr>

270)       

271)       <tr class="alt">

272)         <td><a href="#project-torstatus">TorStatus</a></td>
273)         <td>Client Service</td>

274)         <td>Python, Django</td>

275)         <td>None</td>
276)         <td></td>
277)       </tr>

278)       

279)       <tr>

280)         <td><a href="#project-compass">Compass</a></td>
281)         <td>Client Service</td>
282)         <td>Python</td>
283)         <td>Heavy</td>
284)         <td>gsathya, karsten</td>
285)       </tr>
286)       

287)       <tr class="alt">

288)         <td><a href="#project-weather">Weather</a></td>
289)         <td>Client Service</td>
290)         <td>Python</td>

291)         <td>None</td>

292)         <td>kaner</td>
293)       </tr>

294)       

295)       <tr>

296)         <td><a href="#project-gettor">GetTor</a></td>
297)         <td>Client Service</td>
298)         <td>Python</td>

299)         <td>None</td>

300)         <td>kaner</td>

301)       </tr>

302)       

303)       <tr class="alt">

304)         <td><a href="#project-torcheck">TorCheck</a></td>
305)         <td>Client Service</td>
306)         <td>Python, Perl</td>
307)         <td>None</td>

308)         <td>ioerror</td>

309)       </tr>

310)       

311)       <tr>

312)         <td><a href="#project-onionoo">Onionoo</a></td>
313)         <td>Backend Service</td>

314)         <td>Java, Python</td>

315)         <td>Moderate</td>

316)         <td>karsten, gsathya</td>

317)       </tr>

318)       

319)       <tr class="alt">

320)         <td><a href="#project-bridgedb">BridgeDB</a></td>
321)         <td>Backend Service</td>
322)         <td>Python</td>

323)         <td>None</td>

324)         <td>kaner, nickm</td>

325)       </tr>

326)       

327)       <tr>

328)         <td><a href="#project-torflow">TorFlow</a></td>
329)         <td>Backend Service</td>
330)         <td>Python</td>

331)         <td>None</td>
332)         <td>aagbsn</td>

333)       </tr>

334)       

335)       <tr class="alt">

336)         <td>*<a href="#project-torbel">TorBEL</a></td>
337)         <td>Backend Service</td>
338)         <td>Python</td>
339)         <td>None</td>
340)         <td>Sebastian</td>
341)       </tr>
342)     </table>

343)     

344)     <sub>
345)     * Project is still in an alpha state.
346)     </sub>

347)     

348)     <br /><br />

349)     

350)     <a id="project-tor"></a>
351)     <h3>Tor (<a href="https://gitweb.torproject.org/tor.git">code</a>, <a
352)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Client&component=Tor+Relay&component=vidalia&order=priority">bug
353)     tracker</a>)</h3>

354)     

355)     <p>
356)     Central project, providing the core software for using and participating in
357)     the Tor network. Numerous people contribute to the project to varying
358)     extents, but the chief architects are Nick Mathewson and Roger Dingledine.
359)     </p>

360)     

361)     <p>
362)     <b>Project Ideas:</b><br />

363)     <i><a href="#limitCapabilities">Run With Limited Capabilities</a></i><br />
364)     <i><a href="#torCleanup">Tor Codebase Cleanup</a></i><br />
365)     <i><a href="#httpsImersonation">HTTPS Server Impersonation</a></i><br />
366)     <i><a href="#chutneyExpansion">Make Chutney Do More, More Reliably</a></i>

367)     </p>

368)     

369)     <a id="project-jtor"></a>
370)     <h3><a href="https://github.com/brl/JTor/wiki">JTor</a> (<a
371)     href="https://github.com/brl/JTor">code</a>, <a
372)     href="https://github.com/brl/JTor/issues">bug
373)     tracker</a>)</h3>

374)     

375)     <p>
376)     Java implementation of Tor and successor to <a
377)     href="http://onioncoffee.sourceforge.net/">OnionCoffee</a>. This project
378)     isn't yet complete, and has been inactive since Fall 2010.
379)     </p>

380)     

381)     <a id="project-tbb"></a>
382)     <h3><a href="<page projects/torbrowser>">Tor Browser Bundle</a> (<a
383)     href="https://gitweb.torproject.org/torbrowser.git">code</a>, <a
384)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+bundles/installation&order=priority">bug
385)     tracker</a>)</h3>

386)     

387)     <p>
388)     The Tor Browser Bundle is an easy-to-use portable package of Tor, Vidalia,
389)     and Firefox preconfigured to work together out of the box. This is actively
390)     being worked on by Erinn Clark.
391)     </p>

392)     

393)     <!--

394)     <p>
395)     <b>Project Ideas:</b><br />
396)     <i><a href="#auditTBB">Audit Tor Browser Bundles for data leaks</a></i><br />
397)     <i><a href="#usabilityTesting">Usability testing of Tor</a></i>
398)     </p>

399)     -->

400)     

401)     <a id="project-tails"></a>

402)     <h3><a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> (<a

403)     href="http://git.immerda.ch/?p=amnesia.git;a=summary">code</a>, <a

404)     href="https://tails.boum.org/bugs/">bug

405)     tracker</a>)</h3>

406)     

407)     <p>

408)     The Amnesic Incognito Live System is a live CD/USB distribution

409)     preconfigured so that everything is safely routed through Tor and leaves no
410)     trace on the local system. This is a merger of the Amnesia and <a
411)     href="http://www.anonymityanywhere.com/incognito/">Incognito</a> projects,
412)     and still under very active development.
413)     </p>

414)     

415)     <!--

416)     <p>
417)     <b>Project Ideas:</b><br />

418)     <i><a href="#tailsHiddenServicePetnames">Petname system for Tor hidden
419)     services</a></i><br />
420)     <i><a href="#tailsServer">Tails server: Self-hosted services behind
421)     Tails-powered Tor hidden services</a></i>

422)     </p>

423)     -->

424)     

425)     <a id="project-torsocks"></a>
426)     <h3><a href="http://code.google.com/p/torsocks/">Torsocks</a> (<a
427)     href="https://gitweb.torproject.org/torsocks.git">code</a>, <a
428)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torify&order=priority">bug
429)     tracker</a>)</h3>

430)     

431)     <p>
432)     Utility for adapting other applications to work with Tor. Development has
433)     slowed and compatibility issues remain with some platforms, but it's
434)     otherwise feature complete.
435)     </p>

436)     

437)     <!--

438)     <p>
439)     <b>Project Ideas:</b><br />
440)     <i><a href="#torsocksForOSX">Make torsocks/dsocks work on OS X</a></i>
441)     </p>

442)     -->

443)     

444)     <a id="project-torouter"></a>
445)     <h3><a

446)     href="<wiki>doc/Torouter">Torouter</a> (<a

447)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torouter&order=priority">bug
448)     tracker</a>)</h3>

449)     

450)     <p>
451)     Project to provide an easy-to-use, embedded Tor instance for routers. This

452)     had high activity in late 2010, but has since been rather quiet.

453)     </p>

454)     

455)     <a id="project-vidalia"></a>
456)     <h3><a href="<page projects/vidalia>">Vidalia</a> (<a

457)     href="https://gitweb.torproject.org/vidalia.git">code</a>, <a

458)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Vidalia&order=priority">bug
459)     tracker</a>)</h3>

460)     

461)     <p>
462)     The most commonly used user interface for Tor. Matt Edman started the
463)     project in 2006 and brought it to its current stable state. Development
464)     slowed for several years, though Tomás Touceda has since taken a lead with
465)     pushing the project forward.
466)     </p>

467)     

468)     <!--

469)     <p>
470)     <b>Project Ideas:</b><br />

471)     <i><a href="#vidaliaStatusEventInterface">Tor Controller Status Event Interface for Vidalia</a></i><br />
472)     <i><a href="#vidalia-hidden-service-panel">Torrc plugin and improved hidden service configuration panel</a></i>

473)     </p>

474)     -->

475)     

476)     <a id="project-arm"></a>
477)     <h3><a href="http://www.atagar.com/arm/">Arm</a> (<a

478)     href="https://gitweb.torproject.org/arm.git">code</a>, <a

479)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=arm&order=priority">bug
480)     tracker</a>)</h3>

481)     

482)     <p>
483)     Command-line monitor for Tor. This has been under very active development
484)     by its author, Damian Johnson, since early 2009 to make it a better
485)     general-purpose controller for *nix environments.
486)     </p>

487)     

488)     <!--

489)     <p>
490)     <b>Project Ideas:</b><br />

491)     <i><a href="#armClientMode">Client Mode Use Cases for Arm</a></i><br />
492)     <i><a href="#armGui">GUI for Arm</a></i>

493)     </p>

494)     -->

495)     

496)     <a id="project-orbot"></a>
497)     <h3><a href="https://guardianproject.info/apps/orbot/">Orbot</a> (<a

498)     href="https://gitweb.torproject.org/orbot.git">code</a>, <a

499)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Orbot&order=priority">bug
500)     tracker</a>)</h3>

501)     

502)     <p>
503)     Provides Tor on the Android platform. This was under very active
504)     development up through Fall 2010, after which things have been quiet.
505)     </p>

506)     

507)     <!--

508)     <p>
509)     <b>Project Ideas:</b><br />

510)     <i><a href="#orbot-torbutton">TorButton for Mobile Firefox 4 or Custom Browser on Android</a></i><br />
511)     <i><a href="#orbot-userInterface">Build a better user interface for Orbot</a></i><br />

512)     <i><a href="#orbot-optimisation">Core Tor mobile optimisation</a></i>

513)     </p>

514)     -->

515)     

516)     <a id="project-torbutton"></a>
517)     <h3><a href="<page torbutton/index>">Torbutton</a> (<a
518)     href="https://gitweb.torproject.org/torbutton.git">code</a>, <a
519)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torbutton&order=priority">bug
520)     tracker</a>)</h3>

521)     

522)     <p>
523)     Firefox addon that addresses many of the client-side threats to browsing
524)     the Internet anonymously. Mike has since continued to adapt it to new
525)     threats, updated versions of Firefox, and possibly <a
526)     href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-and-fingerprinting">Chrome
527)     as well</a>.
528)     </p>

529)     

530)     <a id="project-torbirdy"></a>
531)     <h3>TorBirdy (<a
532)     href="https://github.com/ioerror/torbirdy">code</a>, <a
533)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy/dev">bug
534)     tracker</a>)</h3>
535)     
536)     <p>
537)     TorBirdy is Torbutton for Thunderbird and related Mozilla mail clients.
538)     </p>
539)     
540)     <p>
541)     <b>Project Ideas:</b><br />
542)     <i><a href="#improveTorbirdy">Improving TorBirdy</a></i><br />
543)     </p>
544)     

545)     <a id="project-obfsproxy"></a>
546)     <h3><a href="https://gitweb.torproject.org/obfsproxy.git/tree/HEAD:/doc">Obfsproxy</a> (<a
547)     href="https://gitweb.torproject.org/obfsproxy.git">code</a>, <a
548)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Pluggable+transport&order=priority">bug
549)     tracker</a>)</h3>

550)     

551)     <p>
552)     A proxy that shapes Tor traffic, making it harder for censors to detect and
553)     block Tor.
554)     </p>

555)     

556)     <!--

557)     <p>
558)     <b>Project Ideas:</b><br />
559)     <i><a href="#obfsproxy-new-transports">New and innovative pluggable transports</a></i><br />
560)     <i><a href="#obfsproxy-scanning-measures">Defensive bridge active scanning measures</a></i><br />
561)     <i><a href="#obfsproxy-fuzzer">Fuzzer for the Tor protocol</a></i>
562)     </p>

563)     -->

564)     

565)     <a id="project-thandy"></a>
566)     <h3>Thandy (<a
567)     href="https://gitweb.torproject.org/thandy.git">code</a>)</h3>

568)     

569)     <p>
570)     Updater for Tor. The project began in the Summer of 2008 but wasn't
571)     completed. Recently interest in it has been rekindled and many aspects of
572)     its design (including the language it'll be in) are currently in flux.
573)     </p>

574)     

575)     <a id="project-ooni-probe"></a>
576)     <h3>Ooni Probe (<a
577)     href="https://gitweb.torproject.org/ooni-probe.git">code</a>, <a
578)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Ooni&order=priority">bug
579)     tracker</a>)</h3>

580)     

581)     <p>
582)     Censorship scanner, checking your local connection for blocked or modified
583)     content.
584)     </p>

585)     

586)     <a id="project-shadow"></a>
587)     <h3><a href="https://shadow.cs.umn.edu/">Shadow</a> (<a
588)     href="https://github.com/shadow">code</a>, <a
589)     href="https://github.com/shadow/shadow/issues">bug
590)     tracker</a>)</h3>

591)     

592)     <p>
593)     Shadow is a discrete-event network simulator that runs the real
594)     Tor software as a plug-in. Shadow is open-source software that enables
595)     accurate, efficient, controlled, and repeatable Tor experimentation.
596)     </p>

597)     

598)     <a id="project-torctl"></a>
599)     <h3>TorCtl (<a
600)     href="https://gitweb.torproject.org/pytorctl.git">code</a>, <a
601)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torctl&order=priority">bug
602)     tracker</a>)</h3>

603)     

604)     <p>
605)     Python bindings and utilities for using the Tor control port. It has been
606)     stable for several years, with only minor revisions.
607)     </p>

608)     

609)     <a id="project-stem"></a>

610)     <h3><a href="https://stem.readthedocs.org/en/latest/index.html">Stem</a> (<a

611)     href="https://gitweb.torproject.org/stem.git">code</a>, <a

612)     href="https://trac.torproject.org/projects/tor/wiki/doc/stem/bugs">bug

613)     tracker</a>)</h3>

614)     

615)     <p>
616)     Python controller library with a similar scope to TorCtl, but with better
617)     testing, documentation, and API. This project is not yet feature complete.
618)     </p>

619)     

620)     <p>
621)     <b>Project Ideas:</b><br />

622)     <i><a href="#stemUsability">Stem Usability Improvements</a></i>

623)     </p>

624)     

625)     <a id="project-metrics"></a>
626)     <h3><a href="https://metrics.torproject.org/">Metrics</a> (code: <a
627)     href="https://gitweb.torproject.org/metrics-db.git">db</a>, <a
628)     href="https://gitweb.torproject.org/metrics-utils.git">utils</a>, <a
629)     href="https://gitweb.torproject.org/metrics-web.git">web</a>, <a
630)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Metrics&order=priority">bug
631)     tracker</a>)</h3>

632)     

633)     <p>
634)     Processing and analytics of consensus data, provided to users via the
635)     metrics portal. This has been under active development for several years by
636)     Karsten Loesing.
637)     </p>

638)     

639)     <p>
640)     <b>Project Ideas:</b><br />
641)     <i><a href="#metricsSearch">Searchable Tor descriptor and Metrics data archive</a></i> (Python/Django?)
642)     </p>

643)     

644)     <a id="project-atlas"></a>
645)     <h3><a href="https://atlas.torproject.org/">Atlas</a> (<a
646)     href="https://gitweb.torproject.org/atlas.git">code</a>)</h3>

647)     

648)     <p>
649)     Atlas is a web application to discover Tor relays and bridges. It provides
650)     useful information on how relays are configured along with graphics about
651)     their past usage. This is the third evolution of the TorStatus application.
652)     </p>

653)     

654)     <a id="project-torstatus"></a>

655)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorStatus">TorStatus</a> (<a

656)     href="https://gitweb.torproject.org/torstatus.git">code</a>)</h3>

657)     

658)     <p>
659)     Portal providing an overview of the Tor network, and details on any of its
660)     current relays. Though very actively used, this project has been

661)     unmaintained for a long while. The <a
662)     href="https://svn.torproject.org/svn/torstatus/trunk/">original
663)     codebase</a> was written in PHP, and students from Wesleyan wrote the new
664)     Django counterpart.

665)     </p>

666)     

667)     <a id="project-compass"></a>
668)     <h3><a href="https://compass.torproject.org/">Compass</a> (<a
669)     href="https://gitweb.torproject.org/compass.git">code</a>, <a
670)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Compass&order=priority">bug
671)     tracker</a>)</h3>
672)     
673)     <p>
674)     Compass is a web and command line application that filters and
675)     aggregates the Tor relays based on various attributes.
676)     </p>
677)     

678)     <p>
679)     <b>Project Ideas:</b><br />
680)     <i><a href="#compassRefactoring">Compass Refactoring</a></i>
681)     </p>
682)     

683)     <a id="project-weather"></a>

684)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/Weather">Weather</a> (<a

685)     href="https://gitweb.torproject.org/weather.git">code</a>, <a
686)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Weather&order=priority">bug
687)     tracker</a>)</h3>

688)     

689)     <p>
690)     Provides automatic notification to subscribed relay operators when their
691)     relay's unreachable. This underwent a rewrite by the <a
692)     href="http://hfoss.wesleyan.edu/">Wesleyan HFOSS team</a>, which went live
693)     in early 2011.
694)     </p>

695)     

696)     <a id="project-gettor"></a>

697)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/GetTor">GetTor</a> (<a

698)     href="https://gitweb.torproject.org/gettor.git">code</a>, <a

699)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=GetTor&order=priority">bug
700)     tracker</a>)</h3>

701)     

702)     <p>
703)     E-mail autoresponder providing Tor's packages over SMTP. This has been
704)     relatively unchanged for quite a while.
705)     </p>

706)     

707)     <a id="project-torcheck"></a>

708)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorCheck">TorCheck</a> (<a

709)     href="https://svn.torproject.org/svn/check/trunk/">code</a>, <a
710)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Check&order=priority">bug
711)     tracker</a>)</h3>

712)     

713)     <p>
714)     Provides a simple site for determining if the visitor is using Tor or not.
715)     This has been relatively unchanged for quite a while.
716)     </p>

717)     

718)     <a id="project-onionoo"></a>
719)     <h3><a href="<page projects/onionoo>">Onionoo</a> (<a

720)     href="https://gitweb.torproject.org/onionoo.git">java codebase</a>, <a
721)     href="https://gitweb.torproject.org/pyonionoo.git">python
722)     codebase</a>)</h3>

723)     

724)     <p>
725)     Onionoo is a JSON based protocol to learn information about currently
726)     running Tor relays and bridges.
727)     </p>

728)     

729)     <a id="project-bridgedb"></a>

730)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/BridgeDB">BridgeDB</a> (<a

731)     href="https://gitweb.torproject.org/bridgedb.git">code</a>, <a
732)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=BridgeDB&order=priority">bug
733)     tracker</a>)</h3>

734)     

735)     <p>
736)     Backend bridge distributor, handling the various pools they're distributed
737)     in. This was actively developed until Fall of 2010.
738)     </p>

739)     

740)     <a id="project-torflow"></a>

741)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorFlow">TorFlow</a> (<a

742)     href="https://gitweb.torproject.org/torflow.git">code</a>, <a
743)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torflow&order=priority">bug
744)     tracker</a>)</h3>

745)     

746)     <p>
747)     Library and collection of services for actively monitoring the Tor network.
748)     These include the Bandwidth Scanners (measuring throughput of relays) and
749)     SoaT (scans for malicious or misconfigured exit nodes). SoaT was last
750)     actively developed in the Summer of 2010, and the Bandwidth Scanners a few
751)     months later. Both have been under active use since then, but development
752)     has stopped.
753)     </p>

754)     

755)     <a id="project-torbel"></a>
756)     <h3><a

757)     href="https://blog.torproject.org/blog/torbel-tor-bulk-exit-list-tools">TorBEL</a> (<a
758)     href="https://gitweb.torproject.org/torbel.git">code</a>, <a

759)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=TorDNSEL/TorBEL&order=priority">bug
760)     tracker</a>)</h3>

761)     

762)     <p>
763)     The Tor Bulk Exitlist provides a method of identifying if IPs belong to
764)     exit nodes or not. This is a replacement for TorDNSEL which is a stable
765)     (though unmaintained) Haskell application for this purpose. The initial
766)     version of TorBEL was started in GSOC 2010 but since then the project has
767)     been inactive.
768)     </p>

769)     

770)     <a id="Coding"></a>
771)     <a id="Summer"></a>

772)     <h2><a class="anchor" href="#Coding">Project Ideas</a></h2>

773)     

774)     <p>

775)     You may find some of these projects to be good ideas for <a href="<page
776)     about/gsoc>">Google Summer of Code</a> and the <a
777)     href="https://live.gnome.org/OutreachProgramForWomen">Outreach Program for
778)     Women</a>. We have labelled each idea with how useful it would be to the
779)     overall Tor project (priority), how much work we expect it would be (effort
780)     level), how much clue you should start with (skill level), and which of our
781)     <a href="<page about/corepeople>">core developers</a> would be good
782)     mentors. If one or more of these ideas looks promising to you, please <a

783)     href="<page about/contact>">contact us</a> to discuss your plans rather than
784)     sending blind applications. You may also want to propose your own project
785)     idea &mdash; which often results in the best applications.
786)     </p>

787)     

788)     <ol>

789)     

790)     <!--

791)     <a id="auditTBB"></a>

792)     <li>

793)     <b>Audit Tor Browser Bundles for data leaks</b>

794)     <br>

795)     Effort Level: <i>High</i>

796)     <br>

797)     Skill Level: <i>Medium</i>

798)     <br>

799)     Likely Mentors: <i>Jacob</i>

800)     <p>The Tor Browser Bundle incorporates Tor, Firefox, Polipo, and the Vidalia

801)     user interface (and optionally the <a href="http://pidgin.im/">Pidgin</a>
802)     Instant Messaging client). Components are pre-configured to operate in a
803)     secure way, and it has very few dependencies on the installed operating
804)     system. It has therefore become one of the most easy to use, and popular,

805)     ways to use Tor on Windows.</p>
806)     <p>This project is to identify all of the traces left behind by
807)     using a Tor Browser Bundle on Windows, Mac OS X, or Linux.  Developing
808)     ways to stop, counter, or remove these traces is a final step.</p>
809)     <p>Students should be familiar with operating system analysis,

810)     application development on one or preferably all of Windows, Linux,

811)     and Mac OS X, and be comfortable with C/C++ and shell scripting.</p>

812)     <p>Since the core of this project is researching and auditing TBB this is
813)     not likely to be a good GSoC project.</p>

814)     </li>

815)     -->

816)     

817)     <!--

818)     <a id="orbot-userInterface"></a>

819)     <li>

820)     <b>Build a better user interface for Orbot</b>

821)     <br>

822)     Effort Level: <i>Medium</i>

823)     <br>

824)     Skill Level: <i>Medium</i>

825)     <br>

826)     Likely Mentors: <i>Jake</i>
827)     <p>Improved home screen to show confirmation of connection (via a TorCheck
828)     API call), better statistics about data transferred (up/down), number of
829)     circuits connected, quality of connection and so on. The &quot;Tether
830)     Wifi&quot; Android application is a good model to follow in how it shows a
831)     realtime count of bytes transferred as well as notifications when wifi
832)     clients connect. In addition, better handling of Tor system and error
833)     messages would also be very helpful, include use of standard Android
834)     operating systems notifications. The addition of a wizard or tutorial
835)     walkthrough for novice users to explain to them exactly what is and what is
836)     not anonymized or protected would greatly improve the likelihood they will
837)     use Orbot correctly. All of this should work on the range of screens and
838)     device types now offered for Android, from 2&quot; phone to 10&quot;
839)     Tablet.</p>

840)     </li>

841)     -->

842)     

843)     <!--

844)     <a id="armClientMode"></a>

845)     <li>

846)     <b>Client Mode Use Cases for Arm</b>

847)     <br>
848)     Effort Level: <i>High</i>
849)     <br>

850)     Skill Level: <i>Medium</i>

851)     <br>

852)     Likely Mentors: <i>Damian (atagar)</i>
853)     <p><a href="<page projects/arm>">Arm</a> is a Tor command line status
854)     monitor on *nix environments (Linux, Mac, and BSD). It functions much like
855)     top does, giving a CLI overlay of Tor's bandwidth usage, connections,
856)     configuration, log, etc. Thus far its design has been geared for Tor relay
857)     operators. However, this doesn't need to be the case. This project would be
858)     to expand and simplify arm to make it useful for Tor's client users
859)     too.</p>
860)     
861)     <p>This would include UI design, experimenting, and a lot of python
862)     hacking. Here's some ideas for client functionality arm could provide:</p>
863)     
864)     <ul>
865)       <li>A panel for client connections, showing each hop of the user's
866)       circuits with the ISP, country, and jurisdiction where those relays
867)       reside. Other interesting information would be the circuit's latency, how
868)       long its been around, and its possible exit ports. Some of this will be
869)       pretty tricky and require some experimentation to figure out what
870)       information can be fetched safely (for instance, scraping rdns and whois
871)       lookups could give hints about a relay's ISP, but we'd need to do it on
872)       all Tor relays to avoid leaking our connections to the resolver).</li>
873)       
874)       <li>Options to let the user request new circuits (the &quot;New
875)       Identity&quot; feature in Vidalia), select the exit country, etc.</li>
876)       
877)       <li>A panel showing Internet application and if their connections are
878)       being routed through Tor or not (giving a warning if there's leaks).</li>
879)       
880)       <li>The status of the bridges we're configured to use (ie, are they up?).
881)       This would include adding control port functionality to Tor for <a
882)       href="https://trac.torproject.org/projects/tor/ticket/2068">ticket
883)       2068</a>.</li>
884)       
885)       <li>A one click option to set Tor to be a client, relay, or bridge. The
886)       goal would be to make it trivial for users to voluntarily contribute to
887)       the Tor network.</li>
888)       
889)       <li>Menus as an alternative to hotkeys to make the interface more
890)       intuitive and usable for beginners (<a
891)       href="http://gnosis.cx/publish/programming/charming_python_6.html">example</a>).</li>
892)       
893)       <li>Look at Vidalia and TorK for ideas and solicit input from the Tor community.</li>
894)     </ul>
895)     
896)     <p>
897)     More information is available in the following sections of arm's dev notes: <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#ConnectionListingExpansion">Connection Listing Expansion</a>, <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#CircuitDetails">Circuit Details</a>, and <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#ClientModeUseCases">Client Mode Use Cases</a>
898)     </p>

899)     </li>

900)     -->

901)     

902)     <a id="compassRefactoring"></a>

903)     <li>

904)     <b>Compass Refactoring</b>

905)     <br>

906)     Effort Level: <i>Medium</i>

907)     <br>

908)     Skill Level: <i>Medium</i>
909)     <br>
910)     Likely Mentors: <i>gsathya, karsten</i>
911)     <p>
912)     Compass was first designed to be a cli app and then hacked into a web app.
913)     The codebase needs to be refactored such that the main processing code is
914)     separated from the display functions(probably into separate files) and made
915)     modular so that adding more features (<a
916)     href="https://trac.torproject.org/6612">#6612</a>) is easy. For example, the
917)     main processing logic could be in compass.py, whereas print_groups() and other
918)     display related functions could be part of a separate cli.py; web.py would also
919)     have to modified to make use of this new modular code. Bonus points for adding
920)     features to compass(<a href="https://trac.torproject.org/6619">#6619</a>, <a
921)     href="https://trac.torproject.org/6612">#6612</a>, <a
922)     href="https://trac.torproject.org/6728">#6728</a>).
923)     </p>
924)     </li>
925)     
926)     <!--
927)     <a id="orbot-optimisation"></a>
928)     <li>
929)     <b>Core Tor mobile optimisation</b>
930)     <br>
931)     Effort Level: <i>Medium</i>

932)     <br>
933)     Skill Level: <i>High</i>
934)     <br>

935)     Likely Mentors: <i>Jake</i>
936)     <p>
937)     The existing port of Tor to Android is basically a straight
938)     cross-compile to Linux ARM. There has been no work done in looking at
939)     possible optimizations of Tor within a mobile hardware environment or on
940)     mobile networks. In addition, a number of additional Android OS APIs are
941)     available (such as wireless network status) that could be taken
942)     advantage of.
943)     </p>

944)     

945)     <p>
946)     It should be noted, that even without optimisation, Tor is handling the
947)     mobile network environment very well, automatically detecting change in
948)     IP addresses, opening circuits, etc, as the device switches from no
949)     coverage to 2G, 3G or Wifi constantly as it changes position. However,
950)     this observation of &quot;very well&quot;, is just based on user
951)     experience, and not any detailed study of what exactly is happening, and
952)     what threats might exist because of this constantly changing network state.
953)     </p>

954)     

955)     <p>
956)     Finally, the build process needs to be moved to the Android NDK from the
957)     custom GCC toolchain we are now using, and compatibility with Android
958)     2.3 and 3.x Honeycomb OS need to be verified.
959)     </p>

960)     

961)     <p>
962)     For more information see the <a
963)     href="https://svn.torproject.org/svn/projects/android/trunk/Orbot/BUILD">Orbot
964)     build documentation</a>.
965)     </p>

966)     </li>

967)     -->

968)     

969)     <!--

970)     <a id="obfsproxy-scanning-measures"></a>
971)     <li>
972)     <b>Defensive bridge active scanning measures</b>
973)     <br>
974)     Effort Level: <i>High</i>
975)     <br>
976)     Skill Level: <i>High</i>
977)     <br>
978)     Likely Mentors: <i>asn</i>
979)     <p>Involves providing good answers to <a
980)     href="https://lists.torproject.org/pipermail/tor-dev/2011-November/003073.html">this
981)     thread</a> as well as concrete implementation plans for it.</p>

982)     

983)     <p>This also involves implementing proposals <a
984)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/189-authorize-cell.txt">189</a>
985)     and <a
986)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/190-shared-secret-bridge-authorization.txt">190</a>.</p>
987)     </li>

988)     -->

989)     

990)     <!--
991)     <a id="firewallProbeTool"></a>

992)     <li>

993)     <b>Develop a fully automatic firewall-probing system</b>

994)     <br>
995)     Effort Level: <i>Medium to High</i>
996)     <br>
997)     Skill Level: <i>High</i>
998)     <br>

999)     Likely Mentors: <i>Robert Ransom, Jacob</i>
1000)     <p>We would like to have a fully automatic firewall-probing system for
1001)     blocking systems with no long-term state (i.e. firewalls that can
1002)     examine each connection, but do not change their behaviour for future
1003)     connections based on the traffic they have seen).</p>
1004)     <p>Ideally, volunteers would only need to set up one or more test servers,
1005)     and run the probe client program on a publicly accessible computer
1006)     behind the firewall.</p>
1007)     <p>The test tool should:</p>
1008)     <ul>
1009)     <li>generate packet captures on both ends (and send them out to the
1010)         extent possible),</li>
1011)     <li>cycle through all the SSL configurations we might want to test
1012)         through a censorship device, and</li>
1013)     <li>also test some other protocols to see whether they are allowed
1014)         through the firewall (IMAP and other mail protocols, BitTorrent,
1015)         DTLS, etc.).</li>
1016)     </ul>
1017)     </li>
1018)     -->
1019)     
1020)     <!--
1021)     <a id="obfsproxy-fuzzer"></a>
1022)     <li>
1023)     <b>Fuzzer for the Tor protocol</b>
1024)     <br>
1025)     Effort Level: <i>Medium to High</i>
1026)     <br>
1027)     Skill Level: <i>High</i>
1028)     <br>
1029)     Likely Mentors: <i>asn</i>
1030)     <p>Involves researching good and smart ways to fuzz stateful network
1031)     protocols, and also implementing the fuzzer.</p>
1032)     
1033)     <p>We are mostly looking for a fuzzer that fuzzes the Tor protocol
1034)     itself, and not the Tor directory protocol.</p>
1035)     
1036)     <p>Bonus points if it's extremely modular. Relevant research:</p>
1037)     
1038)     <ul>
1039)       <li>PROTOS - Security Testing of Protocol Implementations</li>
1040)       <li>INTERSTATE: A Stateful Protocol Fuzzer for SIP</li>
1041)       <li>Detecting Communication Protocol Security Flaws by Formal Fuzz
1042)       Testing and Machine Learning</li>
1043)       <li>SNOOZE: Toward a Stateful NetwOrk prOtocol fuzZE</li>
1044)       <li>Michal Zalewski's &quot;bugger&quot;</li>
1045)       <li>Also look at the concepts of &quot;model checking&quot; and
1046)       &quot;symbolic execution&quot; to get inspired.</li>
1047)     </ul>
1048)     </li>
1049)     -->
1050)     
1051)     <a id="httpsImersonation"></a>
1052)     <li>
1053)     <b>HTTPS Server Impersonation</b>
1054)     <br>
1055)     Effort Level: <i>Medium to High</i>
1056)     <br>
1057)     Skill Level: <i>Medium to High</i>
1058)     <br>
1059)     Likely Mentors: <i>Nick (nickm)</i>

1060)     <p>

1061)     We have an open proposal for a way to make Tor bridges avoid censorship by
1062)     impersonating an HTTPS server.  Specifically, we need to hack some popular
1063)     SSL "reverse proxy" (your choice) so that it relays regular web connections
1064)     to an HTTP server, but certain connections to a local Tor process.  <a
1065)     href="https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/203-https-frontend.txt">Proposal
1066)     203</a> has a general design sketch.

1067)     </p>
1068)     </li>
1069)     

1070)     <!--
1071)     <a id="geoIPUpgrade"></a>

1072)     <li>

1073)     <b>Improve our GeoIP file format</b>

1074)     <br>

1075)     Effort Level: <i>Medium</i>
1076)     <br>
1077)     Skill Level: <i>Medium to High</i>
1078)     <br>
1079)     Likely Mentors: <i>Robert Ransom</i>
1080)     <p>Currently, Tor bridges and relays read an entire IP-&gt;country database
1081)     into memory from a text file during startup.  We would like to
1082)     distribute this database and store it on disk in a much more compact
1083)     form, and perform IP-&gt;country lookups on it in its on-disk format if
1084)     possible.</p>
1085)     <p>We have <a href='https://trac.torproject.org/projects/tor/ticket/2506'>a
1086)     sketch of a design</a> for a moderately optimized format for IPv4 GeoIP
1087)     data; this project will involve both implementing the IPv4 format and
1088)     designing and implementing a format for IPv6 GeoIP data.</p>
1089)     <p>Since the core of this project is researching IPv6 GeoIP data and
1090)     designing the IPv6 format, this is not likely to be a good GSoC
1091)     project.</p>
1092)     </li>
1093)     -->
1094)     
1095)     <!--
1096)     <a id="unitTesting"></a>
1097)     <li>
1098)     <b>Improve our unit testing process</b>

1099)     <br>
1100)     Effort Level: <i>Medium</i>
1101)     <br>
1102)     Skill Level: <i>Medium</i>
1103)     <br>

1104)     Likely Mentors: <i>Nick, Erinn</i>
1105)     <p>Tor needs to be tested far more thoroughly. This is a
1106)     multi-part effort. To start with, our unit test coverage should
1107)     rise substantially, especially in the areas outside the utility
1108)     functions. This will require significant refactoring of some parts
1109)     of Tor, in order to dissociate as much logic as possible from
1110)     globals.</p>
1111)     <p>Additionally, we need to automate our performance testing. We've got
1112)     buildbot to automate our regular integration and compile testing already
1113)     (though we need somebody to set it up on Windows),
1114)     but we need to get our network simulation tests (as built in <a
1115)     href="https://svn.torproject.org/svn/torflow/trunk/README">TorFlow</a>)
1116)     updated for more recent versions of Tor, and designed to launch a test
1117)     network either on a single machine, or across several, so we can test
1118)     changes in performance on machines in different roles automatically.</p>
1119)     </li>
1120)     -->
1121)     
1122)     <!--
1123)     <a id="vidaliaNetworkMap"></a>
1124)     <li>
1125)     <b>Improved and More Usable Network Map in Vidalia</b>
1126)     <br>
1127)     Effort Level: <i>Medium</i>
1128)     <br>
1129)     Skill Level: <i>Medium</i>
1130)     <br>
1131)     Likely Mentors: <i>Tomás</i>

1132)     <p>

1133)     One of Vidalia's existing features is a network map that shows the user
1134)     the approximate geographic location of relays in the Tor network and
1135)     plots the paths the user's traffic takes as it is tunneled through the
1136)     Tor network. The map is currently not very interactive and has rather
1137)     poor graphics. Instead, we implemented KDE's Marble widget such
1138)     that it gives us a better quality map and enables improved interactivity,
1139)     such as allowing the user to click on individual relays or circuits to
1140)     display additional information. We want to add the ability
1141)     for users to click on a particular relay or a country containing one or
1142)     more Tor exit relays and say, "I want my connections to exit
1143)     from here."
1144)     </p>
1145)     
1146)     <p>
1147)     This project will first involve getting familiar with Vidalia
1148)     and the Marble widget's API. One will then integrate the widget
1149)     into Vidalia and customize Marble to be better suited for our application,
1150)     such as making circuits clickable, storing cached map data in Vidalia's
1151)     own data directory, and customizing some of the widget's dialogs.
1152)     </p>
1153)     
1154)     <p>
1155)     A person undertaking this project should have good C++ development
1156)     experience. Previous experience with Qt and CMake is helpful, but not
1157)     required.

1158)     </p>
1159)     </li>

1160)     -->

1161)     

1162)     <!--
1163)     <a id="resistCensorship"></a>

1164)     <li>

1165)     <b>Improving Tor's ability to resist censorship</b>

1166)     <br>

1167)     Effort Level: <i>Medium to High</i>

1168)     <br>

1169)     Skill Level: <i>High</i>
1170)     <br>
1171)     Likely Mentors: <i>Jake, Thomas</i>
1172)     <p>The Tor 0.2.1.x series makes <a
1173)     href="<svnprojects>design-paper/blocking.html">significant
1174)     improvements</a> in resisting national and organizational censorship.
1175)     But Tor still needs better mechanisms for some parts of its
1176)     anti-censorship design.</p>
1177)     <p>One huge category of work is adding features to our <a
1178)     href="https://gitweb.torproject.org/bridgedb.git?a=tree">BridgeDB</a>
1179)     service (Python). Tor aims to give out <a href="<page docs/bridges>">bridge
1180)     relay addresses</a> to users that can't reach the Tor network
1181)     directly, but there's an arms race between algorithms for distributing
1182)     addresses and algorithms for gathering and blocking them. See <a
1183)     href="<blog>bridge-distribution-strategies">our
1184)     blog post on the topic</a> as an overview, and then look at <a
1185)     href="https://lists.torproject.org/pipermail/tor-dev/2009-December/000666.html">Roger's
1186)     or-dev post</a> from December 2009 for more recent thoughts &mdash; lots of
1187)     design work remains.</p>
1188)     <p>If you want to get more into the guts of Tor itself (C), a more minor problem
1189)     we should address is that current Tors can only listen on a single
1190)     address/port combination at a time. There's
1191)     <a href="<specblob>proposals/118-multiple-orports.txt">a
1192)     proposal to address this limitation</a> and allow clients to connect
1193)     to any given Tor on multiple addresses and ports, but it needs more
1194)     work.</p>
1195)     <p>This project could involve a lot of research and design. One of the big
1196)     challenges will be identifying and crafting approaches that can still
1197)     resist an adversary even after the adversary knows the design, and
1198)     then trading off censorship resistance with usability and
1199)     robustness.</p>
1200)     </li>
1201)     -->
1202)     
1203)     <a id="improveTorbirdy"></a>
1204)     <li>
1205)     <b>Improving TorBirdy</b>
1206)     <br>
1207)     Effort Level: <i>High</i>

1208)     <br>
1209)     Skill Level: <i>Medium to High</i>
1210)     <br>

1211)     Likely Mentors: <i>Sukhbir, Jacob</i>
1212)     <p>
1213)     TorBirdy is Torbutton for Thunderbird, Icedove and related Mozilla mail
1214)     clients.
1215)     </p>
1216)     <p>
1217)     TorBirdy is under active development and is available from <a
1218)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy">our wiki</a>
1219)     and <a
1220)     href="https://addons.mozilla.org/en-US/thunderbird/addon/torbirdy/">mozilla's
1221)     addons site</a>.
1222)     </p>
1223)     
1224)     <p>
1225)     The goal of this project is to improve TorBirdy by:
1226)     </p>
1227)     
1228)     <ul>
1229)       <li>
1230)         Writing a Thunderbird patch to plug known leaks. We have already <a
1231)         href="https://bugzilla.mozilla.org/show_bug.cgi?id=776397">submitted a
1232)         patch to Thunderbird</a> but we anticipate there will be much more work
1233)         required before it is accepted, possibly involving rewriting the entire
1234)         patch; this appears trivial, but it is not, as we are proposing a
1235)         completely new privacy-safe message-ID header generation algorithm for
1236)         Thunderbird.
1237)       </li>
1238)       <li>
1239)         Implementing a JavaScript HTTP proxy (see the <a
1240)         href="https://trac.torproject.org/projects/tor/ticket/6958">ticket</a>)
1241)       </li>
1242)       <li>
1243)         Auditing TorBirdy for leaks and for use with other add-ons (as an
1244)         example see its <a
1245)         href="https://trac.torproject.org/projects/tor/ticket/6319">ticket</a>)
1246)       </li>
1247)     </ul>
1248)     
1249)     <p>
1250)     A student undertaking this project should have some C++ and JavaScript
1251)     development experience. Previous experience with Firefox/Thunderbird
1252)     extension development is a plus, but not required.
1253)     </p>
1254)     </li>
1255)     
1256)     <!--
1257)     <a id="user-space-transport"></a>
1258)     <li>
1259)     <b>Integrating Tor with user-space transport protocol libraries</b>
1260)     <br>
1261)     Effort Level: <i>High</i>
1262)     <br>
1263)     Skill Level: <i>High</i>
1264)     <br>
1265)     Likely Mentors: <i>Steven</i>
1266)     <p>Tor currently sends data over TCP links between nodes. <a
1267)     href="http://static.usenix.org/events/sec09/tech/full_papers/reardon.pdf">Prior
1268)     research</a> has indicated that this may not be optimal, and instead the
1269)     role that TCP plays (congestion control and reliability) should be moved
1270)     into Tor itself. This would allow a number of desirable changes, such as
1271)     preventing errors on one circuit delaying another, and giving Tor control
1272)     and visibility of congestion control.</p>
1273)     <p>There are <a
1274)     href="http://www.cl.cam.ac.uk/~sjm217/papers/tor11datagramcomparison.pdf">many
1275)     ways to do this</a>, each with their own tradeoffs and difficulty of
1276)     implementation. This project will be to select one (or more) option and
1277)     implement it in Tor. The primary goal will be to test this modified version
1278)     of Tor in simulation, but if it turns out to work well, it could be
1279)     deployed in the live Tor network.</p>
1280)     <p>Excellent C programming skills are needed, and knowledge of Tor
1281)     internals are highly desirable.</p>
1282)     </li>
1283)     -->
1284)     
1285)     <a id="chutneyExpansion"></a>
1286)     <li>
1287)     <b>Make Chutney Do More, More Reliably</b>
1288)     <br>
1289)     Effort Level: <i>Medium to High, depending on scope of project</i>
1290)     <br>
1291)     Skill Level: <i>Medium</i>
1292)     <br>

1293)     Likely Mentors: <i>Nick (nickm)</i>
1294)     <p>

1295)     We have a little Python tool called <a
1296)     href="https://gitweb.torproject.org/nickm/chutney.git">Chutney</a> for
1297)     making small local test networks.  It's small, not widely used, and not as
1298)     automated as it could be.

1299)     </p>
1300)     
1301)     <p>

1302)     It would be great to see chutney extended and a set of supporting tests
1303)     built to the point where we could use Chutney to exercise various Tor
1304)     features as an automated integration test.

1305)     </p>

1306)     </li>

1307)     

1308)     <!--
1309)     <a id="torsocksForOSX"></a>
1310)     <li>
1311)     <b>Make torsocks/dsocks work on OS X</b>
1312)     <br>
1313)     Effort Level: <i>Medium</i>
1314)     <br>
1315)     Skill Level: <i>Medium</i>
1316)     <br>
1317)     Likely Mentors: <i>Robert Hogan</i>

1318)     <p>

1319)     <a href="https://code.google.com/p/torsocks/">Torsocks</a> and <a
1320)     href="https://code.google.com/p/dsocks/">dsocks</a> are wrappers that will
1321)     run applications, intercept their outgoing network connections, and push
1322)     those connections through Tor. The goal is to handle applications that
1323)     don't support proxies (or don't supporting them well). To get it right,
1324)     they need to intercept many system calls. The syscalls you need to
1325)     intercept on Linux differ dramatically from those on BSD. So Torsocks
1326)     works fine on Linux, dsocks works ok on BSD (though it may be less
1327)     maintained and thus might miss more syscalls), and nothing works well
1328)     on both. First, we should patch dsocks to use Tor's <i>mapaddress</i>
1329)     commands from the controller interface, so we don't waste a whole
1330)     round-trip inside Tor doing the resolve before connecting. Second,
1331)     we should make our <i>torify</i> script detect which of torsocks or
1332)     dsocks is installed, and call them appropriately. This probably means
1333)     unifying their interfaces, and might involve sharing code between them
1334)     or discarding one entirely.
1335)     </p>
1336)     </li>
1337)     -->
1338)     
1339)     <!--
1340)     <a id="obfsproxy-new-transports"></a>
1341)     <li>
1342)     <b>New and innovative pluggable transports</b>
1343)     <br>
1344)     Effort Level: <i>High</i>
1345)     <br>
1346)     Skill Level: <i>High</i>
1347)     <br>
1348)     Likely Mentors: <i>asn, Steven</i>
1349)     <p>Not-very-smart transports like ROT13 and base64 are nice but not super
1350)     interesting. Other ideas like bittorrent transports might be relevant,
1351)     but you will have to provide security proofs on why they are harder to
1352)     detect and block than other less-sophisticated transports.</p>
1353)     
1354)     <p>The whole point of this project, though, is to come up with new
1355)     transports that we haven't already thought of. Be creative.</p>
1356)     
1357)     <p>Bonus points if your idea is interesting and still implementable
1358)     through the summer period.</p>
1359)     
1360)     <p>More bonus points if it's implemented on top of obfsproxy, or if your
1361)     implementation has a pluggable transport interface on top of it (as
1362)     specified <a href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/180-pluggable-transport.txt">here</a>).</p>
1363)     </li>
1364)     -->
1365)     
1366)     <!--
1367)     <a id="orbot-orlibAndOutreach"></a>
1368)     <li>
1369)     <b>Orbot integration library and community outreach</b>
1370)     <br>
1371)     Effort Level: <i>Low</i>
1372)     <br>
1373)     Skill Level: <i>Medium</i>
1374)     <br>
1375)     Likely Mentors: <i>Nathan (n8fr8)</i>
1376)     <p>
1377)     We need additional work on <a
1378)     href="https://github.com/guardianproject/orlib">ORLib</a>, our library for
1379)     use with third-party application to easily enable them to support
1380)     &quot;Torification&quot; on non-rooted devices (i.e. w/o transparent
1381)     proxying). This library includes a SOCKS client, a wrapper for the Apache
1382)     HTTPClient library, a utility class for detecting the state of Orbot
1383)     connectivity, and other relevant/useful things an Android app might need to
1384)     anonymize itself. This work would includes direct development of the
1385)     library, documentation, and sample code. Outreach or effort to implement
1386)     the library within other open-source apps is also needed.

1387)     </p>
1388)     </li>

1389)     -->
1390)     
1391)     <!--
1392)     <a id="tailsHiddenServicePetnames"></a>
1393)     <li>
1394)     <b>Petname system for Tor hidden services</b>
1395)     <br>
1396)     Effort Level: <i>High</i>
1397)     <br>
1398)     Skill Level: <i>High</i>
1399)     <br>
1400)     Likely Mentors: <i>ague</i>
1401)     <p>Tor provides hidden services. These services are only reachable through
1402)     Tor itself, and provide greater anonymity both for the providers of the
1403)     service and for its users.</p>
1404)     <p>One current downside of Tor hidden services is that they are addressed
1405)     using 80-bit base32-encoded addresses such as "v2cbb2l4lsnpio4q.onion".
1406)     These addresses are hard to remember; this makes them hard to use
1407)     within amnesic environment like Tails.</p>
1408)     <p>The project is to implement a petname system for Tor hidden services:
1409)     a way for users or providers of Tor hidden services to add a simple
1410)     'nickname' to a central database. Users could then query this central
1411)     database to retrieve a full hidden service address by giving
1412)     a nickname.</p>
1413)     <p>Adding petnames to the database could be done using a web interface or
1414)     automated fetch like those described in the <a
1415)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/ideas/xxx-onion-nyms.txt">&quot;.onion
1416)     nym system&quot; proposal</a>.</p>
1417)     <p>Querying the database could be done using a web interface, a REST API and
1418)     a DNS interface.</p>
1419)     <p>In order not to grow indefinitely, the software should make regular tests to
1420)     see if hidden services are still reachable and, depending on the last time
1421)     a nickname was accessed, cleanup the database as necessary.</p>
1422)     <p>The software should allow a distributed, fault-tolerant setup.
1423)     All nodes should have a synchronized copy of the database, should be
1424)     ready to answer queries and should coordinate the tests for hidden
1425)     service availability.</p>
1426)     <p>The resulting codebase must be easy to deploy: it should not be hard to
1427)     setup new databases.</p>
1428)     <p>It is expected that the volunteer will be using Behaviour Driven
1429)     Development methods. Either in Ruby using Cucumber and RSpec, or in
1430)     Python using similar tools.</p>
1431)     </li>
1432)     -->

1433)     

1434)     <a id="limitCapabilities"></a>

1435)     <li>

1436)     <b>Run With Limited Capabilities</b>

1437)     <br>
1438)     Effort Level: <i>Medium to High</i>
1439)     <br>

1440)     Skill Level: <i>High</i>

1441)     <br>
1442)     Likely Mentors: <i>Nick (nickm)</i>
1443)     <p>

1444)     Many modern operating systems give a running program the ability to drop
1445)     capabilities that it no longer needs, and other ways for a program to run
1446)     pieces of itself in a sandbox with diminished privileges.

1447)     </p>
1448)     
1449)     <p>

1450)     We'd like to do this with Tor, to improve its resistance to attacks.  The
1451)     easiest areas to address would be on systems like <a
1452)     href="https://lwn.net/Articles/475361/">recent Linux kernels</a> that make
1453)     it easy to drop or restrict the set of syscalls that a program can invoke.
1454)     That's a great project, but probably not big enough for an internship just
1455)     on its own.  For that, we'd want to make progress on at least multiple
1456)     platforms, or look into refactoring Tor into pieces that need more
1457)     privileges and pieces that don't with an eye towards sandboxing them
1458)     differently.

1459)     </p>
1460)     
1461)     <p>

1462)     See tickets <a href="https://trac.torproject.org/7005">#7005</a> and <a
1463)     href="https://trac.torproject.org/5219">#5219</a>, and their descendants,
1464)     for more information.

1465)     </p>
1466)     </li>
1467)     

1468)     <a id="metricsSearch"></a>

1469)     <li>

1470)     <b>Searchable Tor descriptor and Metrics data archive</b>

1471)     <br>
1472)     Effort Level: <i>Medium</i>
1473)     <br>
1474)     Skill Level: <i>Medium</i>
1475)     <br>

1476)     Likely Mentors: <i>Karsten</i>
1477)     <p>The <a href="https://metrics.torproject.org/data.html">Metrics data
1478)     archive</a> of Tor relay descriptors and other Tor-related network data has
1479)     grown to over 100G in size, bz2-compressed.  We have developed two search
1480)     interfaces: the <a
1481)     href="https://metrics.torproject.org/relay-search.html">relay search</a>
1482)     finds relays by nickname, fingerprint, or IP address in a given month; <a
1483)     href="https://metrics.torproject.org/exonerator.html">ExoneraTor</a> finds
1484)     whether a given IP address was a relay on a given day.</p>
1485)     
1486)     <p>We'd like to have a more general search application for Tor descriptors
1487)     and metrics data.  There are more <a
1488)     href="https://metrics.torproject.org/formats.html">descriptor types</a>
1489)     that we'd like to include in the search.  The search application should
1490)     handle most of them and understand some semantics like what's a timestamp,
1491)     what's an IP address, and what's a link to another descriptor.  Users
1492)     should then be able to search for arbitrary strings or limit their search
1493)     to given time periods or IP address ranges.  Descriptors that reference
1494)     other descriptors should contain links, and descriptors should be able to
1495)     say from where they are linked.  The goal is to make the archive easily
1496)     browsable.</p>
1497)     
1498)     <p>The search application shall be separate from the metrics website and
1499)     shouldn't rely on the metrics website codebase.  The search application
1500)     will contain hourly updated descriptor data from the metrics website via
1501)     rsync.  Programming language and database system are not specified yet,
1502)     though there's a slight preference for Python/Django and Postgres for
1503)     maintenance reasons.  If there are good reasons to pick something else,
1504)     e.g, some NoSQL variant or some search application framework, that's fine,
1505)     too.  Further requirements are that lookups should be really fast and that
1506)     changes to the search application can be implemented in reasonable
1507)     time.</p>
1508)     
1509)     <p>Applications for this project should come with a design of the proposed
1510)     search application, ideally with a proof-of-concept based on a subset of
1511)     the available data to show that it will be able to handle the 100G+ of
1512)     data.</p>

1513)     </li>
1514)     

1515)     <!--
1516)     <a id="simulateSlowConnections"></a>

1517)     <li>

1518)     <b>Simulator for slow Internet connections</b>

1519)     <br>
1520)     Effort Level: <i>Medium</i>
1521)     <br>
1522)     Skill Level: <i>Medium</i>
1523)     <br>

1524)     Likely Mentors: <i>Nick</i>

1525)     <p>

1526)     Many users of Tor have poor-quality Internet connections, giving low
1527)     bandwidth, high latency, and high packet loss/re-ordering. User
1528)     experience is that Tor reacts badly to these conditions, but it is
1529)     difficult to improve the situation without being able to repeat the
1530)     problems in the lab.
1531)     </p>
1532)     
1533)     <p>
1534)     This project would be to build a simulation environment which
1535)     replicates the poor connectivity so that the effect on Tor performance
1536)     can be measured. Other components would be a testing utility to
1537)     establish what are the properties of connections available, and to
1538)     measure the effect of performance-improving modifications to Tor.
1539)     </p>
1540)     
1541)     <p>
1542)     The tools used would be up to the student, but dummynet (for FreeBSD)
1543)     and nistnet (for Linux) are two potential components on which this
1544)     project could be built. Students should be experienced with network
1545)     programming/debugging and TCP/IP, and preferably familiar with C and a
1546)     scripting language.

1547)     </p>
1548)     </li>

1549)     -->

1550)     

1551)     <!--

1552)     <a id="stemPathsupport"></a>
1553)     <li>
1554)     <b>Stem PathSupport Capabilities</b>
1555)     <br>
1556)     Effort Level: <i>High</i>
1557)     <br>
1558)     Skill Level: <i>Medium</i>
1559)     <br>
1560)     Likely Mentors: <i>Damian (atagar)</i>
1561)     <p><a
1562)     href="https://trac.torproject.org/projects/tor/wiki/doc/stem">Stem</a> is a
1563)     python controller library for tor. Like it's predecessor, <a
1564)     href="#project-torctl">TorCtl</a>, it uses tor's <a
1565)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/control-spec.txt">control
1566)     protocol</a> to help developers program against the tor process, enabling
1567)     them to build things similar to <a href="#project-vidalia">Vidalia</a> and
1568)     <a href="#project-arm">arm</a>.</p>

1569)     

1570)     <p>While TorCtl provided a fine first draft for this sort of functionality,
1571)     it has not proved to be extensible nor maintainable. Stem is a rewrite of
1572)     TorCtl with a heavy focus on testing, documentation, and providing a
1573)     developer friendly API.</p>

1574)     

1575)     <p>At the moment stem is still very much incomplete, missing several pieces
1576)     of functionality that TorCtl provides. This is a project to fix that by
1577)     porting TorCtl's <a
1578)     href="https://gitweb.torproject.org/pytorctl.git/blob/HEAD:/PathSupport.py">PathSupport
1579)     module</a> to stem, writing tests for it, and migrate a couple clients to
1580)     use it.</p>

1581)     

1582)     <p>PathSupport provides applications with programmatic control over how
1583)     tor's circuits are built, for instance letting you exit from particular
1584)     relays. This is used by projects like <a href="#project-torbel">TorBEL</a>,
1585)     <a href="#project-torflow">the Bandwidth Scanners, and SoaT</a>.</p>

1586)     

1587)     <p>This project can be broken into three parts...</p>

1588)     

1589)     <ol style="list-style-type: decimal">
1590)       <li><p>Look at PathSupport's clients to figure out how it is used and
1591)       come up with the API that we will use for stem. Note that the goal if
1592)       this project is <b>not</b> to simply copy PathSupport, but to make it
1593)       better. This task would ideally be done as part of writing the GSoC
1594)       application.</p></li>
1595)       <li><p>Implement the PathSupport counterpart for stem. This should be
1596)       done in an incremental fashion, writing the feature, tests, and going
1597)       through a code review before moving on. I'll be pretty anal about making
1598)       it as good as we can during these code reviews so plan for this to take a
1599)       while. ;)</p></li>
1600)       <li><p>The real test of the API that you've developed will come when we
1601)       use it in some real applications. Try to migrate a TorCtl client or two
1602)       to stem, filling in functionality that we're missing and improving our
1603)       API as we discover issues. A particularly good client to start with would
1604)       be TorBEL.</p></li>
1605)     </ol>

1606)     

1607)     <p><b>
1608)     Upon reflection this is not an especially good project for this year's GSoC. You are still perfectly wecome to apply for this project, but <a href="https://trac.torproject.org/projects/tor/wiki/doc/stem">other stem related tasks</a> such as implementing a general controller, descriptor fetching, and client migrations would be better. For the discussion that lead to this see <a href="http://archives.seul.org/or/dev/Apr-2012/msg00006.html">this thread</a>.
1609)     </b></p>
1610)     </li>

1611)     -->

1612)     

1613)     <a id="stemUsability"></a>

1614)     <li>

1615)     <b>Stem Usability Improvements</b>

1616)     <br>
1617)     Effort Level: <i>Medium</i>
1618)     <br>
1619)     Skill Level: <i>Medium</i>
1620)     <br>

1621)     Likely Mentors: <i>Damian (atagar)</i>
1622)     <p>
1623)     <a href="https://stem.readthedocs.org/en/latest/index.html">Stem</a> is a
1624)     python controller library for tor. Like it's predecessor, <a
1625)     href="#project-torctl">TorCtl</a>, it uses tor's <a
1626)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/control-spec.txt">control
1627)     protocol</a> to help developers program against the tor process, enabling
1628)     them to build things similar to <a href="#project-vidalia">Vidalia</a> and
1629)     <a href="#project-arm">arm</a>.
1630)     </p>

1631)     

1632)     <p>
1633)     While TorCtl provided a fine first draft for this sort of functionality,
1634)     it has not proved to be extensible nor maintainable. Stem is a rewrite of
1635)     TorCtl with a heavy focus on testing, documentation, and providing a
1636)     developer friendly API.
1637)     </p>

1638)     

1639)     <p>
1640)     Stem is very nearly feature complete but presently has no users. We
1641)     want to change that prior to making our first release for a couple
1642)     reasons...
1643)     </p>
1644)     
1645)     <ul>
1646)       <li>Make sure that we have a reasonably good API, and improve the rough
1647)       edges that hurt its usability.</li>
1648)       <li>Provide examples for how stem can be used.</li>
1649)     </ul>
1650)     
1651)     <p>
1652)     This project involves several tasks...
1653)     </p>

1654)     

1655)     <ol>
1656)       <li>Move stem's site to Tor's website (<a href="https://trac.torproject.org/projects/tor/ticket/7324">ticket</a>)</li>
1657)       <li>Set up Piwik for our site (<a href="https://trac.torproject.org/projects/tor/ticket/7424">ticket</a>)</li>
1658)       <li>Come up with a better, more developer friendly "Module Overview" for our documentation (<a href="https://stem.readthedocs.org/en/latest/api/control.html">example page</a>). For instance, it would be nice to provide interlinking between the overview and the classes/methods that it lists. This will probably involve asking for help from the <a href="http://sphinx-doc.org/">Sphinx user list</a>.</li>
1659)       <li>Finally get your hands dirty using stem. We want to expand stem's <a href="https://stem.readthedocs.org/en/latest/tutorial.html">tutorial page</a> with more examples. To do this you'll want to both brainstorm some of your own and contact the <a href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev/">tor-dev@ email list</a> to solicit ideas. This last step is pretty open ended, so go nuts with whatever you think will improve stem's usability!</li>
1660)     </ol>

1661)     </li>

1662)     

1663)     <!--

1664)     <a id="tailsServer"></a>
1665)     <li>
1666)     <b>Tails server: Self-hosted services behind Tails-powered Tor hidden services</b>
1667)     <br>
1668)     Effort Level: <i>High</i>
1669)     <br>
1670)     Skill Level: <i>Medium, but wide-scoped</i>
1671)     <br>
1672)     Likely Mentors: <i>intrigeri, anonym</i>
1673)     <p>Let's talk about group collaboration, communication and data sharing
1674)     infrastructure, such as chat servers, wikis, or file repositories.</p>
1675)     <p>Hosting such data and infrastructure <b>in the cloud</b> generally
1676)     implies to trust the service providers not to disclose content, usage or
1677)     users location information to third-parties. Hence, there are many threat
1678)     models in which cloud hosting is not suitable.</p>
1679)     <p>Tor partly answers the <b>users location</b> part; this is great, but
1680)     <b>content</b> is left unprotected.</p>
1681)     <p>There are two main ways to protect such content: either to encrypt it
1682)     client-side (<b>security by design</b>), or to avoid putting it into
1683)     untrusted hands in the first place.</p>
1684)     <p>Cloud solutions that offer security by design are rare and generally
1685)     not mature yet. The <b>Tails server</b> project is about exploring the
1686)     other side of the alternative: avoiding to put private data into
1687)     untrusted hands in the first place.</p>
1688)     <p>This is made possible thanks to Tor hidden services, that allow users
1689)     to offer location-hidden services, and make self-hosting possible in
1690)     many threat models. Self-hosting has its own lot of problems, however,
1691)     particularly in contexts where the physical security of the hosting
1692)     place is not assured. Combining Tor hidden services with Tails'
1693)     amnesia property and limited support for persistent encrypted data
1694)     allows to protect content, to a great degree, even in such contexts.</p>
1695)     <p>In short, setting up a new Tails server would be done by:</p>

1696)     

1697)     <ol style="list-style-type: decimal">
1698)       <li>Alice plugs a USB stick into a running desktop Tails system.</li>
1699)       <li>Alice uses a GUI to easily configure the needed services.</li>
1700)       <li>Alice unplugs the USB stick, that now contains encrypted services
1701)       configuration and data storage space.</li>
1702)       <li>Alice plugs that USB stick (and possibly a Tails Live CD) into the
1703)       old laptop that was dedicated to run Tails server.</li>
1704)       <li>Once booted, Alice enters the encryption passphrase either
1705)       directly using the keyboard or through a web interface listening on the
1706)       local network.</li>
1707)       <li>Then, Bob can use the configured services once he gets a hold on
1708)       the hidden service address. (The <b>petname system for Tor hidden
1709)       services</b> project would be very complementary to this one, by the
1710)       way.)</li>
1711)     </ol>

1712)     

1713)     <p>Tails server should content itself with hardware that is a bit old
1714)     (such as a PIII-450 laptop with 256MB of RAM) and/or half broken (e.g.
1715)     non-functional hard-disk, screen or keyboard).</p>
1716)     <p>The challenges behind this project are:</p>

1717)     

1718)     <ul>
1719)       <li>Design and write the services configuration GUI [keywords: edit
1720)       configuration files, upgrade between major Debian versions,
1721)       debconf].</li>
1722)       <li>How to create the hidden service key? [keywords: Vidalia, control
1723)       protocol].</li>
1724)       <li>Adapt the Tails boot process to allow switching to &quot;server
1725)       mode&quot; when appropriate.</li>
1726)       <li>Add support, to the Tails persistence setup process, for asking an
1727)       encryption passphrase without X, and possibly with a broken keyboard
1728)       and/or screen [keywords: local network, SSL/TLS?, certificate?].</li>
1729)     </ul>

1730)     

1731)     <p>This project can easily grow quite large, so the first task would
1732)     probably be to clarify what it would need to get an initial (minimal
1733)     but working) implementation ready to be shipped to users.</p>

1734)     <p>This project does not require to be an expert in one specific field,
1735)     but it requires to be experienced and at ease with a large scope of
1736)     software development tools, processes, and operating system knowledge.</p>
1737)     <p>Undertaking this project requires in-depth knowledge of Debian-like
1738)     systems (self-test: do the "dpkg conffile" and "debconf preseeding"
1739)     words sound new to your ear?); the Debian Live persistence system
1740)     being written in shell, being at ease with robust shell scripting is
1741)     a must; to end with, at least two pieces of software need to be
1742)     written from scratch (a GUI and a webapp): the preferred languages for
1743)     these tasks would be Python and Perl. Using Behaviour Driven
1744)     Development methods to convey expectations and acceptance criteria
1745)     would be most welcome.</p>
1746)     <p>For more information see https://tails.boum.org/todo/server_edition/</p>

1747)     </li>

1748)     -->

1749)     

1750)     <a id="torCleanup"></a>

1751)     <li>

1752)     <b>Tor Codebase Cleanup</b>

1753)     <br>

1754)     Effort Level: <i>Low to High, depending on subproject chosen</i>

1755)     <br>

1756)     Skill Level: <i>Medium to High</i>

1757)     <br>

1758)     Likely Mentors: <i>Nick (nickm)</i>

1759)     <p>

1760)     The Tor code is almost 10 years old in places, and we haven't always had
1761)     enough time or wisdom to write things as well as we could have.  Our unit
1762)     test coverage is shamefully low, and the dependency graph of our modules is
1763)     shamefully convoluted . We could use refactoring and unit tests!  Please
1764)     look through the Tor source code and look for ugly or tricky code or
1765)     dependencies -- the uglier and trickier the better -- and think about how
1766)     you could make the code look better, read better, and (subject to testing)
1767)     work better.

1768)     </p>

1769)     

1770)     <p>

1771)     If this is for a fun side-project, it would be great for you to work on
1772)     anything that can be made better and more tested.  For an internship-level
1773)     position, we'd hope that you could find a number of particularly tricky or
1774)     knotty piece of the code to clean up, and aim for resolving the ugliest
1775)     problems, not necessarily the easiest.

1776)     </p>

1777)     

1778)     <p>

1779)     For a big project here, it would be great to pick one of the major
1780)     "submodules" of Tor -- path selection, node discovery, directory authority
1781)     operations, directory service -- and refactor its interface completely, to
1782)     minify and codify its points of contact with the rest of Tor.

1783)     </p>
1784)     </li>

1785)     

1786)     <!--

1787)     <a id="vidaliaStatusEventInterface"></a>

1788)     <li>
1789)     <b>Tor Controller Status Event Interface for Vidalia</b>
1790)     <br>
1791)     Effort Level: <i>Medium</i>
1792)     <br>
1793)     Skill Level: <i>Low to Medium</i>
1794)     <br>

1795)     Likely Mentors: <i>Tomás</i>

1796)     <p>There are a number of status changes inside Tor of which the user may need
1797)     to be informed. For example, if the user is trying to set up his Tor as a
1798)     relay and Tor decides that its ports are not reachable from outside
1799)     the user's network, we should alert the user. Currently, all the user
1800)     gets is a couple of log messages in Vidalia's 'message log' window, which they
1801)     likely never see since they don't receive a notification that something
1802)     has gone wrong. Even if the user does actually look at the message log,
1803)     most of the messages make little sense to the novice user.</p>
1804)     <p>Tor has the ability to inform Vidalia of many such status
1805)     changes, and we recently implemented support for a couple of these
1806)     events. Still, there are many more status events which the user should
1807)     be informed of, and we need a better UI for actually displaying them
1808)     to the user.</p>
1809)     <p>The goal of this project then is to design and implement a UI for
1810)     displaying Tor status events to the user. For example, we might put a
1811)     little badge on Vidalia's tray icon that alerts the user to new status
1812)     events they should look at. Double-clicking the icon could bring up a
1813)     dialog that summarizes recent status events in simple terms and maybe
1814)     suggests a remedy for any negative events if they can be corrected by
1815)     the user. Of course, this is just an example and one is free to
1816)     suggest another approach.</p>
1817)     <p>A person undertaking this project should have good UI design and layout
1818)     skills and some C++ development experience. Previous experience with Qt and
1819)     Qt's Designer will be very helpful, but are not required. Some
1820)     English writing ability will also be useful, since this project will
1821)     likely involve writing small amounts of help documentation that should
1822)     be understandable by non-technical users. Bonus points for some graphic
1823)     design/Photoshop fu, since we might want/need some shiny new icons too.</p>
1824)     </li>

1825)     -->

1826)     

1827)     <!--

1828)     <a id="orbot-torbutton"></a>

1829)     <li>

1830)     <b>TorButton for Mobile Firefox 4 or Custom Browser on Android</b>

1831)     <br>

1832)     Effort Level: <i>High</i>

1833)     <br>
1834)     Skill Level: <i>High</i>
1835)     <br>

1836)     Likely Mentors: <i>Jake</i>

1837)     <p>Initial work has been done on implementing a proxy-setting add-on for
1838)     Firefox on Android (see <a
1839)     href="https://github.com/guardianproject/ProxyMob">ProxyMob</a>), but a
1840)     full port of TorButton needs to be done (dependent upon Firefox 4 port of
1841)     TorButton). The other approach is to implement a custom &quot;Tor
1842)     Browser&quot; based on Firefox or Webkit browser. See <a
1843)     href="http://code.google.com/p/torora/wiki/Android">Torora</a> for progress
1844)     on this so far.</p>

1845)     </li>

1846)     -->

1847)     

1848)     <!--

1849)     <a id="vidalia-hidden-service-panel"></a>

1850)     <li>

1851)     <b>Torrc plugin and improved hidden service configuration panel</b>

1852)     <br>
1853)     Effort Level: <i>Medium</i>
1854)     <br>
1855)     Skill Level: <i>Medium</i>
1856)     <br>

1857)     Likely Mentors: <i>Tomás</i>

1858)     <p>Vidalia's configuration handling has changed in the alpha branch. Now
1859)     every Tor option is saved in the torrc file. With that change, the
1860)     Hidden Service configuration panel was removed due to its specificity
1861)     and its multiple bugs.</p>

1862)     

1863)     <p>The idea would be to provide the new Torrc class' functionality to the
1864)     Plugin Engine and with that, create a better Hidden Service
1865)     configuration panel as a plugin.</p>

1866)     

1867)     <p>A person undertaking this project should have good UI design, layout
1868)     skills and some C++ development experience. Previous experience with Qt
1869)     and Qt's Designer will be very helpful, but are not required. Javascript
1870)     knowledge is a plus, but it shouldn't be a problem if the person
1871)     complies with the previous requirements.</p>

1872)     </li>

1873)     -->

1874)     

1875)     <!--

1876)     <a id="usabilityTesting"></a>

1877)     <li>

1878)     <b>Usability testing of Tor</b>

1879)     <br>

1880)     Effort Level: <i>Medium</i>

1881)     <br>

1882)     Skill Level: <i>Low to Medium</i>

1883)     <br>

1884)     Likely Mentors: <i>Andrew</i>

1885)     <p>

1886)     Especially the browser bundle, ideally amongst our target demographic.
1887)     That would help a lot in knowing what needs to be done in terms of bug
1888)     fixes or new features. We get this informally at the moment, but a more
1889)     structured process would be better.

1890)     </p>

1891)     

1892)     <p>

1893)     Please note that since this isn't a coding project, it isn't suitable for
1894)     Google Summer of Code.

1895)     </p>
1896)     </li>

1897)     -->

1898)     

1899)     <a id="docUpdate"></a>

1900)     <li>

1901)     <b>Website and video documentation update</b>

1902)     <br>
1903)     Effort Level: <i>Medium</i>
1904)     <br>
1905)     Skill Level: <i>Medium</i>
1906)     <br>

1907)     Likely Mentors: <i>Runa, Karen</i>

1908)     <p>

1909)     Identify outdated and/or weak pages on torproject.org and re-write the
1910)     documentation to appeal to a less technical, more goal-oriented
1911)     audience. Create a number of 3-5 minute videos with graphically
1912)     portray the written documentation. See
1913)     <a href="https://trac.torproject.org/projects/tor/query?component=Website&status=new">the
1914)     website tickets</a> for more information and a starting point.

1915)     </p>
1916)     </li>

1917)     

1918)     <li>
1919)     <b>Bring up new ideas!</b>

1920)     <br>

1921)     Don't like any of these? Look at the <a

1922)     href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development

1923)     roadmap</a> for more ideas, or just try out Tor, Vidalia, and Torbutton,
1924)     and find out what you think needs fixing.

1925)     Some of the <a href="<spectree>proposals">current proposals</a>

1926)     might also be short on developers.
1927)     </li>

1928)     

1929)     </ol>

1930)     

1931)     <a id="OtherCoding"></a>
1932)     <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
1933)     <ol>
1934)     <li>Tor relays don't work well on Windows XP. On
1935)     Windows, Tor uses the standard <tt>select()</tt> system
1936)     call, which uses space in the non-page pool. This means
1937)     that a medium sized Tor relay will empty the non-page pool, <a

1938)     href="<wiki>doc/WindowsBufferProblems">causing

1939)     havoc and system crashes</a>. We should probably be using overlapped IO
1940)     instead. One solution would be to teach <a
1941)     href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
1942)     overlapped IO rather than select() on Windows, and then adapt Tor to
1943)     the new libevent interface. Christian King made a
1944)     <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
1945)     start</a> on this in the summer of 2007.</li>

1946)     

1947)     <li>We need to actually start building our <a href="<page
1948)     docs/documentation>#DesignDoc">blocking-resistance design</a>. This involves
1949)     fleshing out the design, modifying many different pieces of Tor, adapting
1950)     <a href="<page projects/vidalia>">Vidalia</a> so it supports the
1951)     new features, and planning for deployment.</li>

1952)     

1953)     <li>We need a flexible simulator framework for studying end-to-end
1954)     traffic confirmation attacks. Many researchers have whipped up ad hoc
1955)     simulators to support their intuition either that the attacks work
1956)     really well or that some defense works great. Can we build a simulator
1957)     that's clearly documented and open enough that everybody knows it's
1958)     giving a reasonable answer? This will spur a lot of new research.
1959)     See the entry <a href="#Research">below</a> on confirmation attacks for
1960)     details on the research side of this task &mdash; who knows, when it's
1961)     done maybe you can help write a paper or three also.</li>

1962)     

1963)     <li>Tor 0.1.1.x and later include support for hardware crypto
1964)     accelerators via OpenSSL. It has been lightly tested and is
1965)     possibly very buggy.  We're looking for more rigorous testing,

1966)     performance analysis, and optimally, code fixes to OpenSSL and

1967)     Tor if needed.</li>

1968)     

1969)     <li>Perform a security analysis of Tor with <a

1970)     href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">"fuzz"</a>. Determine

1971)     if there are good fuzzing libraries out there for what we want. Win fame by
1972)     getting credit when we put out a new release because of you!</li>

1973)     

1974)     <li>Tor uses TCP for transport and TLS for link
1975)     encryption. This is nice and simple, but it means all cells
1976)     on a link are delayed when a single packet gets dropped, and
1977)     it means we can only reasonably support TCP streams. We have a <a

1978)     href="<page docs/faq>#TransportIPnotTCP">list

1979)     of reasons why we haven't shifted to UDP transport</a>, but it would
1980)     be great to see that list get shorter. We also have a proposed <a

1981)     href="<specblob>proposals/100-tor-spec-udp.txt">specification

1982)     for Tor and
1983)     UDP</a> &mdash; please let us know what's wrong with it.</li>

1984)     

1985)     <li>We're not that far from having IPv6 support for destination addresses
1986)     (at exit nodes). If you care strongly about IPv6, that's probably the
1987)     first place to start.</li>

1988)     

1989)     <li>We need a way to generate the website diagrams (for example, the "How
1990)     Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
1991)     from source, so we can translate them as UTF-8 text rather than edit
1992)     them by hand with Gimp. We might want to
1993)     integrate this as an wml file so translations are easy and images are
1994)     generated in multiple languages whenever we build the website.</li>

1995)     

1996)     <li>How can we make the various LiveCD/USB systems easier
1997)     to maintain, improve, and document?  One example is <a

1998)     href="https://tails.boum.org/">The Amnesic Incognito Live

1999)     System</a>.
2000)     </li>

2001)     

2002)     <li>
2003)     Another anti-censorship project is to try to make Tor
2004)     more scanning-resistant.  Right now, an adversary can identify <a

2005)     href="<specblob>proposals/125-bridges.txt">Tor bridges</a>

2006)     just by trying to connect to them, following the Tor protocol,
2007)     and seeing if they respond.  To solve this, bridges could <a
2008)     href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
2009)     webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
2010)     and not act like bridges until the user provides a bridge-specific key.
2011)     To start, check out Shane Pope's <a
2012)     href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
2013)     </li>

2014)     

2015)     </ol>

2016)     

2017)     <a id="Research"></a>
2018)     <h2><a class="anchor" href="#Research">Research</a></h2>
2019)     <ol>
2020)     <li>The "end-to-end traffic confirmation attack":
2021)     by watching traffic at Alice and at Bob, we can <a
2022)     href="http://freehaven.net/anonbib/#danezis:pet2004">compare
2023)     traffic signatures and become convinced that we're watching the same
2024)     stream</a>. So far Tor accepts this as a fact of life and assumes this
2025)     attack is trivial in all cases. First of all, is that actually true? How
2026)     much traffic of what sort of distribution is needed before the adversary
2027)     is confident he has won? Are there scenarios (e.g. not transmitting much)
2028)     that slow down the attack? Do some traffic padding or traffic shaping
2029)     schemes work better than others?</li>
2030)     <li>A related question is: Does running a relay/bridge provide additional
2031)     protection against these timing attacks? Can an external adversary that can't
2032)     see inside TLS links still recognize individual streams reliably?
2033)     Does the amount of traffic carried degrade this ability any? What if the
2034)     client-relay deliberately delayed upstream relayed traffic to create a queue
2035)     that could be used to mimic timings of client downstream traffic to make it
2036)     look like it was also relayed? This same queue could also be used for masking
2037)     timings in client upstream traffic with the techniques from <a
2038)     href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
2039)     but without the need for additional traffic. Would such an interleaving of
2040)     client upstream traffic obscure timings for external adversaries? Would the
2041)     strategies need to be adjusted for asymmetric links? For example, on
2042)     asymmetric links, is it actually possible to differentiate client traffic from
2043)     natural bursts due to their asymmetric capacity? Or is it easier than
2044)     symmetric links for some other reason?</li>
2045)     <li>Repeat Murdoch and Danezis's <a
2046)     href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
2047)     Oakland 05</a> on the current Tor network. See if you can learn why it
2048)     works well on some nodes and not well on others. (My theory is that the
2049)     fast nodes with spare capacity resist the attack better.) If that's true,
2050)     then experiment with the RelayBandwidthRate and RelayBandwidthBurst
2051)     options to run a relay that is used as a client while relaying the
2052)     attacker's traffic: as we crank down the RelayBandwidthRate, does the
2053)     attack get harder? What's the right ratio of RelayBandwidthRate to
2054)     actually capacity? Or is it a ratio at all? While we're at it, does a
2055)     much larger set of candidate relays increase the false positive rate
2056)     or other complexity for the attack? (The Tor network is now almost two
2057)     orders of magnitude larger than it was when they wrote their paper.) Be
2058)     sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
2059)     Clog the Queue</a> too.</li>
2060)     <li>The "routing zones attack": most of the literature thinks of
2061)     the network path between Alice and her entry node (and between the
2062)     exit node and Bob) as a single link on some graph. In practice,
2063)     though, the path traverses many autonomous systems (ASes), and <a
2064)     href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
2065)     that the same AS appears on both the entry path and the exit path</a>.
2066)     Unfortunately, to accurately predict whether a given Alice, entry,
2067)     exit, Bob quad will be dangerous, we need to download an entire Internet
2068)     routing zone and perform expensive operations on it. Are there practical
2069)     approximations, such as avoiding IP addresses in the same /8 network?</li>
2070)     <li>Other research questions regarding geographic diversity consider
2071)     the tradeoff between choosing an efficient circuit and choosing a random
2072)     circuit. Look at Stephen Rollyson's <a
2073)     href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
2074)     paper</a> on how to discard particularly slow choices without hurting
2075)     anonymity "too much". This line of reasoning needs more work and more
2076)     thinking, but it looks very promising.</li>
2077)     <li>Tor doesn't work very well when relays have asymmetric bandwidth
2078)     (e.g. cable or DSL). Because Tor has separate TCP connections between
2079)     each hop, if the incoming bytes are arriving just fine and the outgoing
2080)     bytes are all getting dropped on the floor, the TCP push-back mechanisms
2081)     don't really transmit this information back to the incoming streams.
2082)     Perhaps Tor should detect when it's dropping a lot of outgoing packets,
2083)     and rate-limit incoming streams to regulate this itself? I can imagine
2084)     a build-up and drop-off scheme where we pick a conservative rate-limit,
2085)     slowly increase it until we get lost packets, back off, repeat. We
2086)     need somebody who's good with networks to simulate this and help design
2087)     solutions; and/or we need to understand the extent of the performance
2088)     degradation, and use this as motivation to reconsider UDP transport.</li>
2089)     <li>A related topic is congestion control. Is our
2090)     current design sufficient once we have heavy use? Maybe
2091)     we should experiment with variable-sized windows rather
2092)     than fixed-size windows? That seemed to go well in an <a

2093)     href="http://www.psc.edu/index.php/hpn-ssh/638">ssh

2094)     throughput experiment</a>. We'll need to measure and tweak, and maybe
2095)     overhaul if the results are good.</li>
2096)     <li>Our censorship-resistance goals include preventing
2097)     an attacker who's looking at Tor traffic on the wire from <a
2098)     href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
2099)     it from normal SSL traffic</a>. Obviously we can't achieve perfect
2100)     steganography and still remain usable, but for a first step we'd like to
2101)     block any attacks that can win by observing only a few packets. One of
2102)     the remaining attacks we haven't examined much is that Tor cells are 512
2103)     bytes, so the traffic on the wire may well be a multiple of 512 bytes.
2104)     How much does the batching and overhead in TLS records blur this on the
2105)     wire? Do different buffer flushing strategies in Tor affect this? Could
2106)     a bit of padding help a lot, or is this an attack we must accept?</li>
2107)     <li>Tor circuits are built one hop at a time, so in theory we have the
2108)     ability to make some streams exit from the second hop, some from the
2109)     third, and so on. This seems nice because it breaks up the set of exiting
2110)     streams that a given relay can see. But if we want each stream to be safe,
2111)     the "shortest" path should be at least 3 hops long by our current logic, so
2112)     the rest will be even longer. We need to examine this performance / security
2113)     tradeoff.</li>
2114)     <li>It's not that hard to DoS Tor relays or directory authorities. Are client
2115)     puzzles the right answer? What other practical approaches are there? Bonus
2116)     if they're backward-compatible with the current Tor protocol.</li>
2117)     <li>Programs like <a

2118)     href="<page torbutton/index>">Torbutton</a> aim to hide

2119)     your browser's UserAgent string by replacing it with a uniform answer for
2120)     every Tor user. That way the attacker can't splinter Tor's anonymity set
2121)     by looking at that header. It tries to pick a string that is commonly used
2122)     by non-Tor users too, so it doesn't stand out. Question one: how badly
2123)     do we hurt ourselves by periodically updating the version of Firefox
2124)     that Torbutton claims to be? If we update it too often, we splinter the
2125)     anonymity sets ourselves. If we don't update it often enough, then all the
2126)     Tor users stand out because they claim to be running a quite old version
2127)     of Firefox. The answer here probably depends on the Firefox versions seen
2128)     in the wild. Question two: periodically people ask us to cycle through N
2129)     UserAgent strings rather than stick with one. Does this approach help,
2130)     hurt, or not matter? Consider: cookies and recognizing Torbutton users
2131)     by their rotating UserAgents; malicious websites who only attack certain
2132)     browsers; and whether the answers to question one impact this answer.
2133)     </li>
2134)     <li>How many bridge relays do you need to know to maintain
2135)     reachability? We should measure the churn in our bridges. If there is
2136)     lots of churn, are there ways to keep bridge users more likely to stay
2137)     connected?
2138)     </li>
2139)     </ol>

2140)     

2141)     <p>
2142)     <a href="<page about/contact>">Let us know</a> if you've made progress on any
2143)     of these!
2144)     </p>
2145)   </div>
2146)   <!-- END MAINCOL -->
2147)   <div id = "sidecol">
2148) #include "side.wmi"
2149) #include "info.wmi"
2150)   </div>
2151)   <!-- END SIDECOL -->
2152) </div>
2153) <!-- END CONTENT -->