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

29) 

30)     <a id="Documentation"></a>
31)     <h2><a class="anchor" href="#Documentation">Documentation</a></h2>
32)     <ol>

33)     <li>Help translate the
34) <!-- web page and -->
35)     documentation into other

36)     languages. See the <a href="<page getinvolved/translation>">translation
37)     guidelines</a> if you want to help out. We especially need Arabic or
38)     Farsi translations, for the many Tor users in censored areas.</li>
39)     <li>Evaluate and document

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

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

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

44)     programs that interface with Tor</a>. Which ones are useful in which

45)     situations? Please help us test them out and document your results.</li>
46)     </ol>

47) 

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

51)     <li>Monitor some of our <a 
52)     href="https://lists.torproject.org/cgi-bin/mailman/listinfo">public mailing 
53)     lists</a>, like <a 
54)     href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk">tor-talk</a>, <a 
55)     href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays">tor-relays</a>, <a 
56)     href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev">tor-dev</a>, or <a 
57)     href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tbb-dev">tbb-dev</a>, 
58)     and summarize noteworthy exchanges into articles for <a 

59)     href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-news">Tor 

60)     Weekly News</a>.</li>

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

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

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

66)     <a

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

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

69)     <li>Create a poster around a theme, such as "Tor for Freedom!"</li>

70)     <li>Create a t-shirt design that incorporates "<a
71)     href="https://check.torproject.org/">Congratulations! You are using
72)     Tor!</a>" in any language.</li>

73)     <li>Spread the word about Tor at a symposium or conference and use these
74)     <a href="https://media.torproject.org/misc/2015-03-tor-brochure/">Tor
75)     brochures</a> in PDF and ODG format and translated to at least ten
76)     different languages as conversation starter.</li>

77)     </ol>

78) 

79)     <a id="gsoc"></a>
80)     <h2><a class="anchor" href="#gsoc">Google Summer of Code</a></h2>
81) 
82)     <p>
83)     Tor is also taking part in this year's <a

84)     href="https://summerofcode.withgoogle.com/">Google
85)     Summer of Code</a>! To apply but you need to be either <a
86)     href="https://developers.google.com/open-source/gsoc/faq#what_are_the_eligibility_requirements_for_participation">a
87)     present student or just graduated</a>. <b>See our page for <a href="<page
88)     about/gsoc>">Google Summer of Code</a> for more information.</b>

89)     </p>
90) 

91)     <a id="Projects"></a>
92)     <h2><a class="anchor" href="#Projects">Projects</a></h2>

93) 

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

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

101)     </p>

102) 

103)     <p>
104)     For a presentation summarizing many of these projects see...
105)     </p>
106) 
107)     <div id="ecosystem_presentation">

108)       <a href="https://www.youtube.com/watch?v=fb6iqZcQsSg">Tor Ecosystem</a> (<a href="https://media.torproject.org/video/2013-11-t3am-damian-johnson.mp4">mp4</a>, <a href="https://svn.torproject.org/svn/projects/presentations/2013-11-t3am-tor-ecosystem.pdf">slides</a>)

109)     </div>
110) 
111)     <br /></br />
112) 

113)     <table id="projects">
114)       <tr>
115)         <th>Name</th>
116)         <th>Category</th>
117)         <th>Language</th>
118)         <th>Activity</th>
119)         <th>Contributors</th>
120)       </tr>

121) 

122)       <tr>
123)         <td><a href="#project-tor">Tor</a></td>
124)         <td>Core</td>
125)         <td>C</td>
126)         <td>Heavy</td>

127)         <td>nickm, athena, arma</td>

128)       </tr>

129) 

130)       <tr>

131)         <td><a href="#project-torbrowser">Tor Browser</a></td>

132)         <td>Bundle</td>

133)         <td>Javascript, XUL, Scripting</td>

134)         <td>Heavy</td>

135)         <td>mikeperry, Pearl Crescent</td>

136)       </tr>
137) 

138)       <tr>

139)         <td><a href="#project-httpseverywhere">HTTPS Everywhere</a></td>
140)         <td>Browser Add-on</td>
141)         <td>Javascript</td>

142)         <td>Heavy</td>

143)         <td>pde, mikeperry</td>

144)       </tr>

145) 

146)       <tr>

147)         <td><a href="#project-nyx">Nyx</a></td>

148)         <td>User Interface</td>
149)         <td>Python, Curses</td>

150)         <td>Heavy</td>

151)         <td>atagar</td>
152)       </tr>

153) 

154)       <tr>

155)         <td><a href="#project-orbot">Orbot</a></td>
156)         <td>User Interface</td>
157)         <td>Java</td>

158)         <td>Moderage</td>

159)         <td>n8fr8</td>

160)       </tr>

161) 

162)       <tr>

163)         <td><a href="#project-tails">Tails</a></td>
164)         <td>OS image</td>
165)         <td>Sys Admin</td>
166)         <td>Heavy</td>
167)         <td><a href="https://tails.boum.org/">#tails</a></td>

168)       </tr>

169) 

170)       <tr>

171)         <td><a href="#project-torramdisk">tor-ramdisk</a></td>
172)         <td>OS image</td>
173)         <td>Sys Admin</td>

174)         <td>Light</td>

175)         <td>blueness</td>
176)       </tr>
177) 

178)       <tr>

179)         <td><a href="#project-torsocks">Torsocks</a></td>
180)         <td>Usability</td>
181)         <td>C</td>

182)         <td>Light</td>

183)         <td>David Goulet</td>

184)       </tr>
185) 

186)       <tr>
187)         <td><a href="#project-tormessenger">Tor Messenger</a></td>
188)         <td>Bundle</td>
189)         <td>JavaScript, XUL, Scripting</td>
190)         <td>Heavy</td>
191)         <td>arlolra, boklm, sukhe</td>
192)       </tr>
193) 

194)       <tr>

195)         <td><a href="#project-torbirdy">TorBirdy</a></td>
196)         <td>Browser Add-on</td>
197)         <td>JavaScript</td>

198)         <td>Light</td>
199)         <td>sukhe</td>

200)       </tr>

201) 

202)       <tr>

203)         <td><a href="#project-obfsproxy">Obfsproxy</a></td>
204)         <td>Client Add-on</td>

205)         <td>Python</td>

206)         <td>None</td>

207)         <td>asn</td>

208)       </tr>
209) 

210)       <tr>

211)         <td><a href="#project-flash-proxy">Flash Proxy</a></td>
212)         <td>Client Add-on</td>
213)         <td>Python, JavaScript, Go</td>

214)         <td>Light</td>

215)         <td>dcf, infinity0, Arlo Breault</td>

216)       </tr>

217) 

218)       <tr>

219)         <td><a href="#project-shadow">Shadow</a></td>

220)         <td>Simulator</td>

221)         <td>C, Python</td>

222)         <td>Heavy</td>

223)         <td>robgjansen</td>
224)       </tr>

225) 

226)       <tr>
227)         <td><a href="#project-chutney">Chutney</a></td>
228)         <td>Simulator</td>
229)         <td>Python</td>
230)         <td>Light</td>
231)         <td>nickm</td>
232)       </tr>
233) 

234)       <tr>

235)         <td><a href="#project-stem">Stem</a></td>

236)         <td>Library</td>
237)         <td>Python</td>

238)         <td>Heavy</td>

239)         <td>atagar</td>

240)       </tr>

241) 

242)       <tr>

243)         <td><a href="#project-txtorcon">Txtorcon</a></td>
244)         <td>Library</td>
245)         <td>Python, Twisted</td>

246)         <td>Light</td>

247)         <td>meejah</td>
248)       </tr>

249) 

250)       <tr>

251)         <td><a href="#project-tlsdate">Tlsdate</a></td>
252)         <td>Utility</td>
253)         <td>C</td>

254)         <td>None</td>

255)         <td>ioerror</td>
256)       </tr>

257) 

258)       <tr>

259)         <td><a href="#project-metrics">Metrics</a></td>
260)         <td>Client Service</td>
261)         <td>Java</td>

262)         <td>Moderate</td>

263)         <td>karsten</td>
264)       </tr>

265) 

266)       <tr>

267)         <td><a href="#project-atlas">Atlas</a></td>
268)         <td>Client Service</td>
269)         <td>JavaScript</td>

270)         <td>None</td>

271)         <td></td>

272)       </tr>

273) 

274)       <tr>
275)         <td><a href="#project-globe">Globe</a></td>
276)         <td>Client Service</td>
277)         <td>JavaScript</td>

278)         <td>None</td>
279)         <td></td>

280)       </tr>
281) 

282)       <tr>

283)         <td><a href="#project-compass">Compass</a></td>
284)         <td>Client Service</td>
285)         <td>Python</td>

286)         <td>None</td>
287)         <td></td>

288)       </tr>

289) 

290)       <tr>

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

293)         <td>Java</td>

294)         <td>Light</td>

295)         <td>karsten</td>

296)       </tr>
297) 

298)       <tr>
299)         <td><a href="#project-exitmap">ExitMap</a></td>
300)         <td>Backend Service</td>
301)         <td>Python</td>

302)         <td>Light</td>

303)         <td>phw</td>
304)       </tr>
305) 

306)       <tr>
307)         <td><a href="#project-doctor">DocTor</a></td>
308)         <td>Backend Service</td>
309)         <td>Python</td>

310)         <td>Light</td>

311)         <td>atagar</td>
312)       </tr>
313) 

314)       <tr>

315)         <td><a href="#project-weather">Weather</a></td>
316)         <td>Client Service</td>
317)         <td>Python</td>

318)         <td>None</td>

319)         <td>kaner</td>
320)       </tr>

321) 

322)       <tr>

323)         <td><a href="#project-gettor">GetTor</a></td>
324)         <td>Client Service</td>
325)         <td>Python</td>

326)         <td>Light</td>
327)         <td>ilv</td>

328)       </tr>

329) 

330)       <tr>

331)         <td><a href="#project-torcheck">TorCheck</a></td>
332)         <td>Client Service</td>

333)         <td>Go</td>

334)         <td>None</td>

335)         <td>Arlo</td>

336)       </tr>

337) 

338)       <tr>

339)         <td><a href="#project-bridgedb">BridgeDB</a></td>
340)         <td>Backend Service</td>
341)         <td>Python</td>

342)         <td>Light</td>

343)         <td>isis</td>

344)       </tr>

345) 

346)       <tr>

347)         <td><a href="#project-ooni-probe">Ooni Probe</a></td>

348)         <td>Scanner</td>
349)         <td>Python</td>

350)         <td>Moderate</td>

351)         <td>hellais, aagbsn</td>

352)       </tr>
353) 

354)       <tr>
355)         <td><a href="#project-torps">TorPS</a></td>
356)         <td>Backend Service</td>
357)         <td>Python</td>

358)         <td>None</td>

359)         <td>Aaron Johnson</td>
360)       </tr>
361) 

362)       <tr>

363)         <td><a href="#project-torflow">TorFlow</a></td>
364)         <td>Backend Service</td>
365)         <td>Python</td>

366)         <td>None</td>

367)         <td>aagbsn</td>

368)       </tr>

369) 

370)       <tr>

371)         <td><a href="#project-tor2web">Tor2web</a></td>
372)         <td>Client Service</td>

373)         <td>Python</td>

374)         <td>Heavy</td>

375)         <td>evilaliv3, hellais</td>

376)       </tr>

377) 

378)       <tr>

379)         <td><a href="#project-anonbib">Anonbib</a></td>
380)         <td>Website</td>

381)         <td>Python</td>

382)         <td>Light</td>

383)         <td>arma, nickm</td>
384)       </tr>

385)     </table>

386) 

387)     <sub>
388)     * Project is still in an alpha state.
389)     </sub>

390) 

391)     <br /><br />

392) 

393)     <a id="project-tor"></a>
394)     <h3>Tor (<a href="https://gitweb.torproject.org/tor.git">code</a>, <a

395)     href="https://trac.torproject.org/projects/tor/report/12">bug

396)     tracker</a>)</h3>

397) 

398)     <p>
399)     Central project, providing the core software for using and participating in
400)     the Tor network. Numerous people contribute to the project to varying
401)     extents, but the chief architects are Nick Mathewson and Roger Dingledine.
402)     </p>

403) 

404)     <p>
405)     <b>Project Ideas:</b><br />

406)     <i><a href="#improveHiddenServices">Help improve Tor hidden services</a></i>

407)     </p>

408) 

409)     <a id="project-torbrowser"></a>

410)     <h3><a href="<page projects/torbrowser>">Tor Browser</a> (<a

411)     href="https://gitweb.torproject.org/tor-browser.git">code</a>, <a

412)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torbutton&component=Tor+Launcher&component=Tor+Browser&component=Tor+bundles%2Finstallation&col=id&col=summary&col=status&col=owner&col=type&col=priority&col=milestone&order=priority">bug

413)     tracker</a>, <a href="https://www.torproject.org/projects/torbrowser/design/">design doc</a>)</h3>
414) 

415)     <p>

416)     Tor Browser is an easy-to-use, portable package of Tor, HTTPS-Everywhere, 
417)     NoScript, TorLauncher, Torbutton, and a Firefox fork, all  preconfigured 
418)     to work together out of
419)     the box. The modified copy of Firefox aims to resolve the

420)     privacy and security issues in mainline version.

421)     </p>

422) 

423)     <p>
424)     <b>Project Ideas:</b><br />
425)     <i><a href="#panopticlick">Panopticlick</a></i><br />
426)     </p>
427) 

428)     <a id="project-httpseverywhere"></a>
429)     <h3><a href="https://www.eff.org/https-everywhere">HTTPS Everywhere</a> (<a
430)     href="https://gitweb.torproject.org/https-everywhere.git">code</a>, <a
431)     href="https://trac.torproject.org/projects/tor/report/19">bug

432)     tracker</a>)</h3>

433) 

434)     <p>

435)     HTTPS Everywhere is a Firefox and Chrome extension that encrypts
436)     your communications with many major websites, making your browsing
437)     more secure.

438)     </p>

439) 

440)     <a id="project-nyx"></a>
441)     <h3><a href="https://www.atagar.com/arm/">Nyx</a> (<a
442)     href="https://gitweb.torproject.org/nyx.git">code</a>, <a

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

445) 

446)     <p>

447)     Nyx (previously <i>arm</i>) is a terminal status monitor for Tor

448)     intended for command-line aficionados, ssh connections, and anyone with a
449)     tty terminal. This works much like top does for system usage, providing
450)     real time statistics for bandwidth, resource usage, connections, and quite
451)     a bit more.

452)     </p>

453) 

454)     <p>
455)     <b>Project Ideas:</b><br />
456)     <i><a href="#expand_nyx">Expand Nyx</a></i>
457)     </p>
458) 

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

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

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

464) 
465)     <p>

466)     Provides Tor on the Android platform. The project is under active 
467)     development, updates to latest Tor releases, and working to stay up to 
468)     date with all changes in Android and mobile threats.

469)     </p>
470) 
471)     <a id="project-tails"></a>
472)     <h3><a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> (<a

473)     href="https://git-tails.immerda.ch/tails/">code</a>, <a
474)     href="https://labs.riseup.net/code/projects/tails">bug

475)     tracker</a>, <a href="https://tails.boum.org/doc">documentation</a>, <a
476)     href="https://tails.boum.org/contribute/design/">design</a>, <a
477)     href="https://tails.boum.org/contribute">contribute</a>)</h3>

478) 
479)     <p>
480)     The Amnesic Incognito Live System is a live CD/USB distribution
481)     preconfigured so that everything is safely routed through Tor and leaves no
482)     trace on the local system. This is a merger of the Amnesia and <a
483)     href="http://www.anonymityanywhere.com/incognito/">Incognito</a> projects,
484)     and still under very active development.
485)     </p>
486) 

487)     <a id="project-torramdisk"></a>
488)     <h3><a href="http://opensource.dyc.edu/tor-ramdisk">Tor-ramdisk</a> (<a

489)     href="https://gitweb.torproject.org/tor-ramdisk.git">code</a>, <a

490)     href="http://opensource.dyc.edu/tor-ramdisk-documentation">documentation</a>)</h3>

491) 
492)     <p>

493)     Tor-ramdisk is a uClibc-based micro Linux distribution whose sole
494)     purpose is to securely host a Tor server purely in RAM.

495)     </p>
496) 

497)     <a id="project-torsocks"></a>

498)     <h3>Torsocks (<a

499)     href="https://gitweb.torproject.org/torsocks.git">code</a>, <a
500)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torify&order=priority">bug
501)     tracker</a>)</h3>
502) 

503)     <p>

504)     Utility for adapting other applications to work with Tor. Development has
505)     slowed and compatibility issues remain with some platforms, but it's
506)     otherwise feature complete.

507)     </p>

508) 

509)     <a id="project-tormessenger"></a>
510)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/doc/TorMessenger">Tor Messenger</a> (<a
511)     href="https://gitweb.torproject.org/tor-messenger-build.git">code</a>, <a
512)     href="https://trac.torproject.org/projects/tor/query?status=!closed&component=Tor+Messenger">bug tracker</a>)</h3>
513) 
514)     <p>
515)     Tor Messenger is a cross-platform chat program that aims to be secure by default and sends all of its traffic over Tor.
516)     </p>
517) 

518)     <a id="project-torbirdy"></a>
519)     <h3>TorBirdy (<a

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

521)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy/dev">bug
522)     tracker</a>)</h3>

523) 

524)     <p>
525)     TorBirdy is Torbutton for Thunderbird and related Mozilla mail clients.
526)     </p>

527) 

528)     <p>
529)     <b>Project Ideas:</b><br />
530)     <i><a href="#makeTorbirdyBetter">Make TorBirdy Better</a></i>
531)     </p>
532) 

533)     <a id="project-obfsproxy"></a>

534)     <h3><a href="<page projects/obfsproxy>">Obfsproxy</a> (<a

535)     href="https://gitweb.torproject.org/pluggable-transports/obfsproxy.git">code</a>,
536)     <a 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

537)     tracker</a>)</h3>

538) 

539)     <p>
540)     A proxy that shapes Tor traffic, making it harder for censors to detect and

541)     block Tor. This has both a C and python implementation.

542)     </p>

543) 

544)     <a id="project-flash-proxy"></a>
545)     <h3><a href="https://crypto.stanford.edu/flashproxy/">Flash Proxy</a> (<a
546)     href="https://gitweb.torproject.org/flashproxy.git">code</a>, <a
547)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_information&status=needs_review&status=needs_revision&status=new&status=reopened&component=Flashproxy">bug
548)     tracker</a>)</h3>

549) 

550)     <p>
551)     Pluggable transport using proxies running in web browsers to defeat
552)     address-based blocking.
553)     </p>

554) 

555)     <a id="project-chutney"></a>
556)     <h3>Chutney (<a href="https://gitweb.torproject.org/chutney.git">code</a>,
557)     <a href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_information&status=needs_review&status=needs_revision&status=new&status=reopened&component=Chutney">bug
558)     tracker</a>)</h3>
559) 
560)     <p>
561)     Integration test suite that spawns a local tor network, checking the
562)     interactions of its components.
563)     </p>
564) 

565)     <a id="project-shadow"></a>
566)     <h3><a href="https://shadow.cs.umn.edu/">Shadow</a> (<a
567)     href="https://github.com/shadow">code</a>, <a
568)     href="https://github.com/shadow/shadow/issues">bug
569)     tracker</a>)</h3>

570) 

571)     <p>
572)     Shadow is a discrete-event network simulator that runs the real
573)     Tor software as a plug-in. Shadow is open-source software that enables
574)     accurate, efficient, controlled, and repeatable Tor experimentation.

575)     For another simulator, see <a
576)     href="http://crysp.uwaterloo.ca/software/exptor/">ExperimenTor</a>.

577)     </p>

578) 

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

580)     <h3><a href="https://stem.torproject.org/">Stem</a> (<a

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

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

583)     tracker</a>)</h3>

584) 

585)     <p>

586)     Python controller library for scripts and controller applications using
587)     Tor.

588)     </p>

589) 

590)     <p>
591)     <b>Project Ideas:</b><br />
592)     <i><a href="#descriptor_parsing_in_go">Stem Descriptor Parsing in Go</a></i>
593)     </p>
594) 

595)     <a id="project-txtorcon"></a>

596)     <h3><a href="https://txtorcon.readthedocs.org">Txtorcon</a> (<a

597)     href="https://github.com/meejah/txtorcon">code</a>, <a

598)     href="https://github.com/meejah/txtorcon/issues">bug tracker</a>)</h3>

599) 

600)     <p>
601)     Twisted-based asynchronous Tor control protocol implementation. Includes
602)     unit-tests, examples, state-tracking code and configuration abstraction.
603)     Used by OONI and APAF.
604)     </p>

605) 

606)     <p>
607)     <b>Project Ideas:</b><br />
608)     <i><a href="#txtorcon_use_txaio">Convert txtorcon to use txaio</a></i><br />
609)     <i><a href="#txtorcon_use_pytest">Convert txtorcon to py.test</a></i>
610)     </p>
611) 

612)     <a id="project-tlsdate"></a>
613)     <h3>Tlsdate (<a href="https://github.com/ioerror/tlsdate">code</a>)</h3>

614) 

615)     <p>
616)     tlsdate: secure parasitic rdate replacement
617)     </p>

618) 

619)     <p>
620)     tlsdate sets the local clock by securely connecting with TLS to remote
621)     servers and extracting the remote time out of the secure handshake. Unlike
622)     ntpdate, tlsdate uses TCP, for instance connecting to a remote HTTPS or TLS
623)     enabled service, and provides some protection against adversaries that try
624)     to feed you malicious time information.
625)     </p>

626) 

627)     <a id="project-metrics"></a>
628)     <h3><a href="https://metrics.torproject.org/">Metrics</a> (code: <a
629)     href="https://gitweb.torproject.org/metrics-db.git">db</a>, <a

630)     href="https://gitweb.torproject.org/metrics-web.git">web</a>)</h3>

631) 

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

635)     Karsten Loesing. See also <a
636)     href="https://gitweb.torproject.org/torperf.git">TorPerf</a>.

637)     </p>

638) 

639)     <a id="project-atlas"></a>
640)     <h3><a href="https://atlas.torproject.org/">Atlas</a> (<a
641)     href="https://gitweb.torproject.org/atlas.git">code</a>)</h3>

642) 

643)     <p>
644)     Atlas is a web application to discover Tor relays and bridges. It provides
645)     useful information on how relays are configured along with graphics about

646)     their past usage.

647)     </p>

648) 

649)     <p>

650)     This is the spiritual successor to <a
651)     href="https://gitweb.torproject.org/torstatus.git">TorStatus</a>, the <a

652)     href="https://svn.torproject.org/svn/torstatus/trunk/">original

653)     codebase</a> for which was written in PHP, and rewritten by students from
654)     Wesleyan as Django.

655)     </p>

656) 

657)     <a id="project-globe"></a>
658)     <h3><a href="http://globe.rndm.de/">Globe</a> (<a
659)     href="https://github.com/makepanic/globe">code</a>, <a
660)     href="https://github.com/makepanic/globe/issues">bug tracker</a>)</h3>
661) 
662)     <p>
663)     Globe is a web application that allows you to search for Tor relays and
664)     bridges. It gives you a detailed overview of properties and configurations
665)     of a relay or bridge.
666)     </p>
667) 

668)     <a id="project-compass"></a>
669)     <h3><a href="https://compass.torproject.org/">Compass</a> (<a
670)     href="https://gitweb.torproject.org/compass.git">code</a>, <a
671)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Compass&order=priority">bug
672)     tracker</a>)</h3>

673) 

674)     <p>
675)     Compass is a web and command line application that filters and
676)     aggregates the Tor relays based on various attributes.
677)     </p>

678) 
679)     <a id="project-onionoo"></a>

680)     <h3><a href="https://onionoo.torproject.org/">Onionoo</a> (<a
681)     href="https://gitweb.torproject.org/onionoo.git">code</a>,
682)     <a href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Onionoo&order=priority">bug tracker</a>)</h3>

683) 
684)     <p>
685)     Onionoo is a JSON based protocol to learn information about currently
686)     running Tor relays and bridges.
687)     </p>
688) 

689)     <a id="project-exitmap"></a>
690)     <h3><a href="http://www.cs.kau.se/philwint/spoiled_onions/">ExitMap</a> (<a
691)     href="https://github.com/NullHypothesis/exitmap">code</a>, <a
692)     href="https://github.com/NullHypothesis/exitmap/issues">bug tracker</a>)</h3>
693) 
694)     <p>

695)     Scanner for the Tor network by Philipp Winter to detect malicious and
696)     misconfigured exits. For more information about how it works see his <a
697)     href="http://www.cs.kau.se/philwint/spoiled_onions/pets2014.pdf">Spoiled

698)     Onions</a> research paper.
699)     </p>
700) 

701)     <p>
702)     <b>Project Ideas:</b><br />
703)     <i><a href="#exitmap_improvements">Exitmap Improvements</a></i>
704)     </p>
705) 

706)     <a id="project-doctor"></a>
707)     <h3>DocTor (<a
708)     href="https://gitweb.torproject.org/doctor.git">code</a>, <a
709)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=DocTor&order=priority">bug
710)     tracker</a>)</h3>
711) 
712)     <p>
713)     DocTor is a notification service that monitors newly published descriptor
714)     information for issues. This is primarily a service to help the tor
715)     directory authority operators, but it also checks for a handful of other
716)     issues like sybil attacks.
717)     </p>
718) 

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

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

721)     href="https://gitweb.torproject.org/weather.git">code</a>, <a
722)     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
723)     tracker</a>)</h3>

724) 

725)     <p>
726)     Provides automatic notification to subscribed relay operators when their
727)     relay's unreachable. This underwent a rewrite by the <a
728)     href="http://hfoss.wesleyan.edu/">Wesleyan HFOSS team</a>, which went live
729)     in early 2011.
730)     </p>

731) 

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

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

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

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

737) 

738)     <p>
739)     E-mail autoresponder providing Tor's packages over SMTP. This has been
740)     relatively unchanged for quite a while.
741)     </p>

742) 

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

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

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

746)     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
747)     tracker</a>)</h3>

748) 

749)     <p>

750)     Site for determining if the visitor is using Tor or not.

751)     </p>

752) 

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

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

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

758) 

759)     <p>
760)     Backend bridge distributor, handling the various pools they're distributed
761)     in. This was actively developed until Fall of 2010.
762)     </p>

763) 
764)     <a id="project-ooni-probe"></a>

765)     <h3><a href="https://ooni.torproject.org/">Ooni Probe</a> (<a

766)     href="https://gitweb.torproject.org/ooni-probe.git">code</a>, <a
767)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Ooni&order=priority">bug
768)     tracker</a>)</h3>
769) 
770)     <p>
771)     Censorship scanner, checking your local connection for blocked or modified
772)     content.
773)     </p>
774) 

775)     <a id="project-torps"></a>
776)     <h3>TorPS</a> (<a href="https://github.com/torps/torps">code</a>)</h3>
777) 
778)     <p>
779)     The Tor Path Simulator (TorPS) is a tool for efficiently simulating
780)     path selection in Tor. It chooses circuits and assigns user streams to
781)     those circuits in the same way that Tor does. TorPS is fast enough to
782)     perform thousands of simulations over periods of months.
783)     </p>
784) 

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

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

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

790) 

791)     <p>
792)     Library and collection of services for actively monitoring the Tor network.
793)     These include the Bandwidth Scanners (measuring throughput of relays) and
794)     SoaT (scans for malicious or misconfigured exit nodes). SoaT was last
795)     actively developed in the Summer of 2010, and the Bandwidth Scanners a few
796)     months later. Both have been under active use since then, but development
797)     has stopped.
798)     </p>

799) 
800)     <a id="project-tor2web"></a>
801)     <h3><a
802)     href="http://wiki.tor2web.org/index.php/Main_Page">Tor2web</a> (<a
803)     href="https://github.com/globaleaks/tor2web-3.0/wiki">code</a>)</h3>
804) 
805)     <p>
806)     Tor2web allows Internet users to browse websites running in <a
807)     href="<page docs/hidden-services>">Tor hidden services</a>. It trades
808)     user anonymity for usability by allowing anonymous content to be
809)     distributed to non-anonymous users.
810)     </p>
811) 

812)     <a id="project-anonbib"></a>
813)     <h3><a
814)     href="http://freehaven.net/anonbib/">Anonymity Bibliography</a> (<a
815)     href="https://gitweb.torproject.org/anonbib.git">code</a>)</h3>
816) 
817)     <p>

818)     Anonbib is a list of important papers in the field of anonymity. It's
819)     also a set of scripts to generate the website from Latex (bibtex). If
820)     we're missing any important papers, please let us know!

821)     </p>
822) 

823)     <a id="Coding"></a>
824)     <a id="Summer"></a>

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

826) 

827)     <p>

828)     You may find some of these projects to be good ideas for <a href="<page
829)     about/gsoc>">Google Summer of Code</a> and the <a
830)     href="https://live.gnome.org/OutreachProgramForWomen">Outreach Program for

831)     Women</a>. We have labelled each idea with which of our <a href="<page
832)     about/corepeople>">core developers</a> would be good mentors. If one or
833)     more of these ideas looks promising to you, please <a href="<page
834)     about/contact>">contact us</a> to discuss your plans rather than sending
835)     blind applications. You may also want to propose your own project idea
836)     &mdash; which often results in the best applications.

837)     </p>

838) 

839)     <ol>

840) 

841)     <a id="makeTorbirdyBetter"></a>
842)     <li>
843)     <b>Make TorBirdy Better</b>
844)     <br>

845)     Language: <i>JavaScript, C++</i>

846)     <br>

847)     Likely Mentors: <i>Sukhbir Singh (sukhe)</i>

848)     <br><br>

849)     <p>
850) TorBirdy is an extension that configures Thunderbird to make connections over
851) the Tor anonymity network. TorBirdy has been under development for quite a
852) while but there are two known leaks that prevent it from being used by a wider

853) audience. As part of this project, you will be working on implementing a HTTP
854) proxy.

855)     </p>
856) 
857)     <p>

858) <b>HTTP Proxy</b> TorBirdy needs a HTTP proxy or a HTTP -&gt; SOCKS5 shim. Please look at

859) ticket <a href="https://trac.torproject.org/projects/tor/ticket/6958">#6958</a>

860) for more information. Note: this has to be done using JavaScript and without using

861) an external proxy.
862)     </p>
863) 
864)     <p>
865) If time permits and you are awesome enough to finish the above two tasks, you

866) will be working on the <a href="https://trac.torproject.org/projects/tor/query?status=!closed&component=TorBirdy">
867) remaining TorBirdy tickets</a>.

868)     </p>
869) 
870)     <p>

871) Applicants should be familiar with JavaScript (and preferably C++ as well). As
872) part of your application for this project, please submit code samples for
873) previous JavaScript projects that you have developed, or point us to projects
874) you have been involved with (links to a public Git/GitHub repository
875) preferred).  Prior extension development is a big plus and will be given
876) preference during application ranking.

877)     </p>
878) 
879)     <p>

880) You may contact the mentors on IRC for more information. (sukhe on #tor-dev, #tor on irc.oftc.net)

881)     </p>
882)     </li>
883) 

884)     <a id="improveHiddenServices"></a>
885)     <li>
886)     <b>Help improve Tor hidden services</b>
887)     <br>

888)     Language: <i>C</i>

889)     <br>

890)     Likely Mentors: <i>George (asn)</i>

891)     <br><br>

892)     <p>
893) We're working on a revamp of the entire Tor hidden service design to
894) improve the security and reliability of the hidden service system.
895)     </p>
896) 
897)     <p>
898) This is a big project: see

899) <a href="https://gitweb.torproject.org/torspec.git/tree/proposals/224-rend-spec-ng.txt">proposal

900) 224</a> for the latest design.  Are you interested in implementing some
901) part of that?
902)     </p>
903) 
904)     <p>
905) This is a very ambitious project, so we're deliberately not suggesting
906) particular sub-topics.  If you're interested in participating, try to
907) read and understand the <a

908) href="https://gitweb.torproject.org/torspec.git/tree/rend-spec.txt">existing

909) design</a> and the design proposal for the new design, and then talk to
910) us about what part you want to work on.
911)     </p>
912) 
913)     <p>
914) As part of the application process for this project, please contribute a
915) nontrivial patch to Tor -- ideally, one that will affect some part of
916) the codebase that you want to work on.
917)     </p>
918)     </li>
919) 

920)     <a id="exitmap_improvements"></a>
921)     <li>
922)     <b>Exitmap Improvements</b>
923)     <br>

924)     Language: <i>Python</i>

925)     <br>
926)     Likely Mentors: <i>Philipp (phw)</i>

927)     <br><br>

928)     <p>
929) The Tor Project makes use of the Python tool <a
930) href="https://gitweb.torproject.org/user/phw/exitmap.git/">Exitmap</a> to
931) systematically scan for malicious and misbehaving exit relays.  Once such a
932) relay is found, it is assigned the BadExit flag which prevents clients from
933) selecting the relay as last hop in their circuit.
934)     </p>
935) 
936)     <p>
937) Exitmap supports scanning modules which implement a specific scan over
938) exit relays.  Examples are the DNS module which checks for DNS poisoning
939) or the patching check module which looks out for tampered file
940) downloads.
941)     </p>
942) 
943)     <p>
944) This project is meant to extend exitmap in several ways.  First, it
945) should be made fully autonomous.  That means that exitmap should be able
946) to run in the background, periodically fetch new relay descriptors, and
947) have a smart algorithm which keeps scanning all exit relays
948) periodically.  Second, exitmap should be able to emulate some user
949) interaction and dynamically "explore" the web in order to detect
950) tampering.  Third, unit tests should be added for existing and new code
951) in order to make the code base more robust.
952)     </p>
953)     </li>

954) 

955)     <a id="expand_nyx"></a>
956)     <li>
957)     <b>Expand Nyx</b>
958)     <br>

959)     Language: <i>Python</i>

960)     <br>
961)     Likely Mentors: <i>Damian (atagar)</i>

962)     <br><br>

963)     <p>
964) Nyx (previously known as <a href="https://www.atagar.com/arm/">arm</a>) is an
965) ncurses monitor that provides Tor relay operators...
966)     </p>
967) 
968)     <ul>
969)       <li><a href="https://www.atagar.com/arm/images/screenshot_page1_full.png">bandwidth graphs and event log</a></li>
970)       <li><a href="https://www.atagar.com/arm/images/screenshot_page2_full.png">connections</a></li>
971)       <li><a href="https://www.atagar.com/arm/images/screenshot_page3_full.png">user's torrc</a></li>
972)       <li><a href="https://www.atagar.com/arm/images/screenshot_configPanel_full.png">config editor</a></li>
973)     </ul>
974) 
975)     <p>
976) Nyx is presently under development in preparation for its next release. If you
977) like python, terminals, and collaborating on an active codebase this just might
978) be the project for you!
979)     </p>
980) 
981)     <p>
982) Proposals should involve a grab-bag of moderately small improvements you'd like
983) to make. You're encouraged to brainstorm ideas of their own but here's a few to
984) get ya started...
985)     </p>
986) 
987)     <ul>
988)       <li>Bring back the <a href="https://www.atagar.com/arm/images/screenshot_interpretor_full.png">interpreter panel</a>. This panel was dropped when refactoring Nyx, but it would be a neat component to bring back. You can <a href="https://gitweb.torproject.org/nyx.git/tree/src/cli/interpretorPanel.py?h=release">find old code for it in the history</a> and Stem (the library backing Nyx) has a much improved <a href="https://stem.torproject.org/tutorials/down_the_rabbit_hole.html">variant of this we can leverage</a>. This task would involve writing the curses code around Stem's interpreter functions.</li>
989)       <li>Windows support. Like most curses applications Nyx doesn't run natively on Windows. We've had dozens of users request this and <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#Windows">it should be possible</a>. This would involve supporting PDCurses and expanding Stem to be able to query the cpu/memory usage of the tor process.</li>
990)       <li>Unit testing! Nyx has <a href="https://gitweb.torproject.org/nyx.git/tree/test">started adding tests</a> but it's still very minimal. Achieving any substantial code coverage will require us to figure out how to unit test curses components.</li>
991)       <li>Onionoo provides additional relay information that could enrich our connection panel such as geoip and rdns. Trick is that at present we can only query it on a per-relay basis which would leak our connections (no-go for security). However, if we could get information about all relays in bulk it would sidestep this. For some old thoughts on this see <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#CircuitDetails">here</a>.</li>

992)       <li>Relay setup wizard. Our last release had this (screenshots: <a href="https://www.atagar.com/transfer/tmp/arm_wizard1.png">1</a>, <a href="https://www.atagar.com/transfer/tmp/arm_wizard2.png">2</a>, <a href="https://www.atagar.com/transfer/tmp/arm_wizard3.png">3</a>). This has been removed because including it directly in Nyx confused users, but we might want to resurrect it as a separate <i>setup-tor-relay</i> command.</li>

993)       <li><a href="https://trac.torproject.org/projects/tor/ticket/18499">Improved dialog</a> for selecting events to log.</li>

994)       <li>... and more! Again, don't hesitate to propose ideas of your own.</li>
995)     </ul>
996) 
997)     <p>
998)     <b>As part of your application for this project please get your hands wet with the codebase by contributing patches for <a href="https://gitweb.torproject.org/nyx.git">Nyx</a> and <a href="https://stem.torproject.org/faq.html#how-do-i-get-started">Stem</a>!</b>
999)     </p>
1000)     </li>
1001) 

1002)     <a id="descriptor_parsing_in_go"></a>
1003)     <li>
1004)     <b>Stem Descriptor Parsing in Go</b>
1005)     <br>
1006)     Language: <i>Go, Python</i>
1007)     <br>
1008)     Likely Mentors: <i>Damian (atagar), Philipp (phw)</i>
1009)     <br><br>
1010)     <p>
1011)     Tor consists of two parts: the application and a distributed network of a
1012)     few thousand volunteer relays. Information about these relays is public,
1013)     and made up of documents called <b><a href="https://stem.torproject.org/tutorials/mirror_mirror_on_the_wall.html#what-is-a-descriptor">descriptors</a></b>. We have
1014)     <a href="https://stem.torproject.org/tutorials/mirror_mirror_on_the_wall.html#are-there-any-other-parsing-libraries">three libraries capable of reading these documents</a>...
1015)     </p>
1016) 
1017)     <ul>
1018)       <li><b><a href="https://stem.torproject.org/">Stem</a></b> (Python)</li>
1019)       <li><b><a href="https://gitweb.torproject.org/metrics-lib.git/">Metrics-lib</a></b> (Java)</li>
1020)       <li><b><a href="https://gitweb.torproject.org/user/phw/zoossh.git/">Zoossh</a></b> (Go)</li>
1021)     </ul>
1022) 
1023)     <p>
1024)     Stem is the most feature rich but slowest, and conversely Zoossh is fastest
1025)     but limited. But what if Stem used CFFI bindings to do the heavy lifting in
1026)     Go? Could we unify these libraries, getting the feature set of Stem with
1027)     the performance of Zoossh?
1028)     </p>
1029) 
1030)     <p>
1031)     <b>Applicants should be familiar with both Python and Go. As part of your
1032)     application for this project please write a demo CFFI binding for Stem as a
1033)     proof of concept.</b> Bonus points if you <a
1034)     href="https://stem.torproject.org/faq.html#how-do-i-get-started">get your
1035)     hands wet by contributing patches</a>!
1036)     </p>
1037)     </li>
1038) 

1039)     <a id="txtorcon_use_txaio"></a>
1040)     <li>
1041)     <b>Convert txtorcon to use txaio</b>
1042)     <br>
1043)     Language: <i>Python, asyncio, Twisted</i>
1044)     <br>
1045)     Likely Mentors: <i>meejah</i>
1046)     <br><br>
1047)     <p>
1048)     txtorcon is currently supports only Twisted users. Re-working txtorcon
1049)     to use the txaio library would allow users to choose between Twisted and
1050)     asyncio for the client code.
1051)     </p>
1052) 
1053)     <p>
1054)     This would involve fairly extensive refactoring to txtorcon, as it
1055)     currently makes heavy use of @inlineCallbacks which doesn't work with
1056)     txaio. A prospective student should be very familiar with event-based
1057)     programming in general, and be familiar with one of Twisted or asyncio.
1058)     See also: https://github.com/meejah/txtorcon/issues/135
1059)     </p>
1060)     </li>
1061) 
1062)     <a id="txtorcon_use_pytest"></a>
1063)     <li>
1064)     <b>Convert txtorcon to py.test</b>
1065)     <br>
1066)     Language: <i>Python, Twisted</i>
1067)     <br>
1068)     Likely Mentors: <i>meejah</i>
1069)     <br><br>
1070)     <p>
1071)     Currently txtorcon uses the built-in "unittest" module, as well as
1072)     Twisted's Deferred-respecting extensions on top. However, meejah has
1073)     found py.test's "fixture" approach to be much more powerful in other
1074)     situations.
1075)     </p>
1076) 
1077)     <p>
1078)     This project would be to port at least part of txtorcon's test-suite to
1079)     use py.test style tests and fixtures and evaluate: are the tests easier
1080)     to read? are there fewer lines of code? If so, the rest of the suite
1081)     should be ported and txtorcon switched over to use py.test exclusively.
1082)     </p>
1083) 
1084)     <p>
1085)     As some of txtorcon's tests aren't very well-written, this would take a
1086)     prospective student who is very strong in unit-testing knowledge. As
1087)     txtorcon is event-based, familiarity with that style of programming
1088)     (preferrably with Twisted) is ideal.
1089)     See also: https://github.com/meejah/txtorcon/issues/136
1090)     </p>
1091)     </li>
1092) 

1093)     <a id="coniks_in_messenger"></a>
1094)     <li>
1095)     <b>Implement and Integrate CONIKS for Tor Messenger</b>
1096)     <br>

1097)     Language: <i>C, JavaScript</i>

1098)     <br>

1099)     Likely Mentors: <i>Marcela (masomel), Arlo (arlolra)</i>

1100)     <br><br>

1101)     <p>
1102) CONIKS is an end-user key management and verification system for end-to-end
1103) secure communication services, which improves upon existing key management
1104) systems by providing both strong security and better usability using a model
1105) called key transparency. CONIKS does this by requiring providers to manage
1106) tamper-evident, publicly-auditable key directories, which contain mappings from
1107) usernames to public keys, on behalf of their users. This design makes it easier
1108) for users (both "default" users and power users) to establish trust since they
1109) don't have to worry about or even see keys, but users also don't have to
1110) trust the provider to be well-behaved because the CONIKS client can run as
1111) part of the secure messaging app and automatically check that the service
1112) provider doesn’t map spurious keys to their users' usernames, and it can
1113) verify that observed name-to-key mappings are consistent with what other
1114) clients in the system are seeing. Unlike existing key transparency solutions,
1115) CONIKS also provides strong privacy guarantees by employing cryptographic
1116) primitives for robust data obfuscation.
1117)     </p>
1118) 
1119)     <p>
1120) The CONIKS system design, protocols, and proof-of-concept are described in
1121) great detail in the <a
1122) href="https://www.usenix.org/system/files/conference/usenixsecurity15/sec15-paper-melara.pdf">CONIKS
1123) research paper</a>, and basic reference implementations of a CONIKS key server
1124) and a CONIKS client are avialable on <a
1125) href="https://github.com/coniks-sys/coniks-ref-implementation">Github</a>.
1126)     </p>
1127) 
1128)     <p>
1129) This project has two main components: (1) designing and implementing a CONIKS
1130) key server tailored to Tor Messenger users, and (2) building a CONIKS client
1131) which integrates with the Tor Messenger client. One challenge the applicant
1132) will face is ensuring that the key server design is efficient and scalable for
1133) large volumes of users, concurrent traffic and guarantees this scalability even
1134) as Tor Messenger's user base grows. On the client side, the main challenges
1135) will be to focus on space efficiency as well as minimizing computational
1136) overhead when implementing the CONIKS consistency checks, and determining how
1137) to best communicate CONIKS consistency check results to users in the UI. Since
1138) Tor Messenger does not hand out online identities per se, as most online
1139) communication services do (like, say, Twitter, in which each user has a unique
1140) handle), the CONIKS key server for Tor Messenger will have to map usernames
1141) from third-party communication services to the encryption keys used in Tor
1142) Messenger. One additional important challenge that the applicant will have to
1143) help address is ensuring that each such third-party username remains unique in
1144) the Tor Messenger space and that such external, third-party identities are
1145) indeed controlled by the expected user of that third-party communication
1146) service.
1147)     </p>
1148) 
1149)     <p>
1150) Some design and implementation questions have been discussed in <a
1151) href="https://trac.torproject.org/projects/tor/ticket/17961">Ticket #17961</a>.
1152)     </p>
1153) 
1154)     <p>
1155) The applicant should have some familiarity with well-known crypto primitives
1156) and algorithms, as well as have a basic understanding of the key transparency
1157) model. Client side integration will require some basic use of JavaScript.
1158) Consider submitting a patch for <a
1159) href="https://github.com/arlolra/ctypes-otr/issues">one of the open key
1160) verification issues</a> as part of the application process.
1161)     </p>
1162)     </li>

1163) 
1164)     <a id="panopticlick"></a>
1165)     <li>
1166)     <b>Panopticlick</b>
1167)     <br>
1168)     Likely Mentors: <i>Georg (GeKo)</i>
1169)     <p>
1170) 
1171) The <a href="https://panopticlick.eff.org">Panopticlick project by the EFF</a>
1172) revolutionized how people think about <a
1173) href="https://panopticlick.eff.org/browser-uniqueness.pdf">browser
1174) fingerprinting</a>, both by developing tests and metrics to measure browser
1175) fingerprintability, and by crowdsourcing the evaluation and contribution of
1176) individual browser features to overall fingerprintability.
1177) 
1178)     </p>
1179)     <p>
1180) 
1181) Unfortunately, the way Panopticlick is designed <a
1182) href="https://blog.torproject.org/blog/effs-panopticlick-and-torbutton">makes
1183) it difficult</a> to evaluate defenses to browser fingerprinting, especially
1184) for browsers with a relatively small userbase such as Tor Browser. This is
1185) because any approach we take to reduce fingerprinting automatically makes our
1186) users more distinct from the previous users who submitted their fingerprint
1187) data to the EFF. Indeed, it is also impossible to ever expect that users of
1188) one browser will ever be able to blend in with users of another browser
1189) (Chrome users will always be distinguishable from Firefox users for example,
1190) based on feature set alone).
1191) 
1192)    </p>
1193)    <p>
1194) 
1195) To address this, we would like to have <a
1196) href="https://trac.torproject.org/projects/tor/ticket/6119">our own
1197) fingerprint test suite</a> to evaluate the fingerprintability of each browser
1198) feature for users running a specific Tor Browser version. There are also <a
1199) href="https://trac.torproject.org/projects/tor/query?keywords=~tbb-fingerprinting">additional
1200) fingerprinting tests</a> we can add beyond those deployed by Panopticlick.
1201)    </p>
1202)    <p>
1203) 
1204) For this project, the student would develop a website that users can
1205) voluntarily visit to test and record their Tor Browser fingerprint.  The user
1206) should get feedback on how she performed and the test results should be
1207) available in a machine readable format (e.g. JSON), broken down by Tor Browser
1208) version.  In a second step one could think about adding more sophisticated
1209) tests or supporting other browser vendors that might want to test the
1210) uniformity amongst their userbase as well. Of course, results from each
1211) browser would also need to be broken down by both browser implementation and
1212) version, so that results would only reflect the population of that specific
1213) implementation.
1214) 
1215)     </p>
1216)     </li>
1217) 

1218)     <a id="stegotorus"></a>
1219)     <li>
1220)     <b>Make Stegotorus deployment ready</b>
1221)     <br>
1222)     Language: <i>C++</i>
1223)     <br>
1224)     Likely Mentors: <i>vmon</i>
1225)     <br><br>
1226)     <p>
1227)     <a
1228)     href="https://github.com/TheTorProject/stegotorus/tree/master/src">Stegotorus</a>
1229)     is a PT framework which streamline the development stealthier pluggable
1230)     transport. An HTTP pluggable transport is already implemented in Stegotorus
1231)     framework and can be used when encrypted payloads are throttled and only
1232)     ephemeral connections are tolerated.
1233)     </p>
1234) 
1235)     <p>
1236)     The majority of work on Stegotorus is done and it can be deployed with a relatively minor improvements including:
1237)     </p>
1238) 
1239)     <ul>
1240)       <li><b>#8098 A config file file for Stegotorus</b>
1241)         <p>
1242)         Stegotorus needs many configuration settings specially on the bridge
1243)         side. This include also the configuration required by each steg module.
1244)         Currently the configuration is fed to Stegotorus as command line
1245)         arguments but a file like torrc is needed so all tweaking can be read
1246)         from there.
1247)         </p>
1248) 
1249)         <p><i>
1250)         Current Status and work needed to be done: The code for reading the
1251)         config file is written by SRI but it is not yet used in the Stegotorus
1252)         to read the config.
1253)         </i></p>
1254)       </li>
1255) 
1256)       <li><b>#8101 Debugging the transparent proxy</b>
1257)         <p>
1258)         Stegotorus http module uses other websites payload to hide and serve
1259)         censored traffic. As such it needs to decide if the request is
1260)         genuinely to the auxiliary website, in that case becomes a transparent
1261)         proxy and serves the website content as requested, or if the request is
1262)         actually a request to serve censored material which should be delivered
1263)         to steg modules.
1264)         </p>
1265) 
1266)         <p><i>
1267)         Current Status: This is completely implemented. However, the transparent proxy sometimes crashes and need to be triaged, debugged and fixed.
1268)         </i></p>
1269)       </li>
1270) 
1271)       <li><b>#11337 refactoring the steg module code</b>
1272)         <p>
1273)         The http steg module code, although not essentials to the core of the
1274)         Stegotorus. needs some improvement and clean up. The solution is to
1275)         refactor the steg modules as children of FileStegMod.
1276)         </p>
1277) 
1278)         <p><i>
1279)         Current status and work needed to be done: This has already been done
1280)         but still needs testing and refactoring before it can be reliably merge
1281)         to the master branch.
1282)         </i></p>
1283)       </li>
1284) 
1285)       <li><b>#8089 Adding Elligator to Stegotorus handshake and test</b>
1286)         <p>
1287)         The current Stegotorus handshake is distinguishable from random byte
1288)         string, which can be used to flag and detect Stegotorus traffic
1289)         deterministically and need to be implemented similar to
1290)         ScrambleSuite. Also because the capacity of client to server channel
1291)         might be slim depending on the choice of steg module it is desirable
1292)         to be implemented using Elliptic curve crypto. Hence, Elligator
1293)         protocol is ideal solution for this situation. All we need is to replace Stegotorus handshake by Elligator.
1294)         </p>
1295) 
1296)         <p><i>
1297)         Current Status and work needed to be done: Elligator handshake code is
1298)         included in stegotorus code base, it is only needed to be called by
1299)         instead of the current handshake and be tested.
1300)         </i></p>
1301)       </li>
1302) 
1303)       <li><b>Make Stegotorus memory safe by using shared pointers</b>
1304)         <p>
1305)         Stegotorus has large code base and it is not written in a memory safe
1306)         languages. To facilitate its audit, we need to replace (almost all) use
1307)         of pointers to shared pointers.
1308)         </p>
1309) 
1310)         <p><i>
1311)         Current Status: No progress has not been done.
1312)         </i></p>
1313)       </li>
1314) 
1315)       <li><b>Security Audit and writing more unit test</b>
1316)         <p>
1317)         To be able to deploy Stegotorus for real world use we need to audit the
1318)         code and write more unit test covering new aspects of the Stegotorus
1319)         (new http transport, proxy server, Elligator handshake)
1320)         </p>
1321) 
1322)         <p><i>
1323)         Current Status: No progress has been done.
1324)         </i></p>
1325)       </li>
1326) 
1327)       <li><b>SRI branch merging</b>
1328)         <p>
1329)         Stegotorus has been forked from the initial development from SRI. Now
1330)         that SRI is hosting Stegotorus publicly it is desirable to merge the
1331)         two branches so we can benefit from both developments.
1332)         </p>
1333) 
1334)         <p><i>
1335)         Current Status: No progress has been done.
1336)         </i></p>
1337)       </li>
1338) 
1339)       <li><b>#8099 deterministic build</b>
1340)         <p>
1341)         To make deterministic build possible we need to build many of
1342)         Stegotorus dependency from scratch. Boost library is a a huge
1343)         dependency for Stegotorus to access the file system. As we are only
1344)         planning to deploy Stegotorus bridges on Linux machines we can simplify
1345)         such access without that dependency. By dropping such dependency, it
1346)         should be straight forward to have deterministic build for Stegotorus.
1347)         </p>
1348) 
1349)         <p><i>
1350)         Current Status: No progress has been done.
1351)         </i></p>
1352)       </li>
1353)     </ul>
1354)     </li>
1355) 

1356)     <a id="letsEncryptClient"></a>
1357)     <li>
1358)     <b>Expand the OS and Server Support of the Let's Encrypt Client</b>
1359)     <br>
1360)     Language: <i>Python, Bash</i>
1361)     <br>
1362)     Likely Mentors: <i>Brad Warren (bmw)</i>
1363)     <br><br>
1364)     <p>
1365)     <a href="https://letsencrypt.org/">Let's Encrypt</a> is a free and open
1366)     certificate authority that allows its users to setup HTTPS on their web
1367)     server in a matter of seconds. The project uses a new protocol called ACME
1368)     to automatically perform domain validation and certificate issuance.
1369)     </p>
1370) 
1371)     <p>
1372)     The Let's Encrypt client currently works on most Unix-like OSes and is
1373)     able to automatically set up HTTPS on many Apache configurations. The
1374)     purpose of this project is to expand Let's Encrypt support to new
1375)     systems.
1376)     </p>
1377) 
1378)     <p>
1379)     Potential targets include:
1380)     </p>
1381) 
1382)     <ul>
1383)       <li>Better OS X support including a port or Homebrew package</li>
1384)       <li>A Let's Encrypt client for Windows / IIS</li>
1385)       <li>Handling of more obscure Apache configurations</li>
1386)       <li>Automated HTTPS configuration for other web servers such as Nginx or lighttpd</li>
1387)       <li>Improved support people using shared hosting who are unable to use the full Let's Encrypt client on their server</li>
1388)     </ul>
1389)     </li>
1390) 

1391)     <a id="ahmiaSearch"></a>
1392)     <li>
1393)     <b>Ahmia - Hidden Service Search</b>
1394)     <br>
1395)     Language: <i>Python, Django</i>
1396)     <br>
1397)     Likely Mentors: <i>Juha Nurmi (numes), George (asn)</i>
1398)     <br><br>
1399)     <p>
1400)     Ahmia is open-source search engine software for Tor hidden service deep
1401)     dark web sites. You can test the running search engine at ahmia.fi. For
1402)     more information see our <a
1403)     href="https://blog.torproject.org/category/tags/ahmiafi">blog post about
1404)     Ahmia's GSoC2014 development</a>.
1405)     </p>
1406) 
1407)     <p>
1408)     Ahmia is a working search engine that indexes, searches, and catalogs
1409)     content published on Tor Hidden Services. Furthermore, it is an environment
1410)     to share meaningful insights, statistics, insights, and news about the Tor
1411)     network itself. In this context, there is a lot of work to do.
1412)     </p>
1413) 
1414)     <p>
1415)     The Ahmia web service is written using the Django web framework. As a
1416)     result, the server-side language is Python. On the client-side, most of the
1417)     pages are plain HTML. There are some pages that require JavaScript, but the
1418)     search itself works without client-side JavaScript.
1419)     </p>
1420) 
1421)     <p>
1422)     There are several possible directions for this project, including...
1423)     </p>
1424) 
1425)     <ol>
1426)       <li>Improving the search results (very important)<br />
1427)         <ul>
1428)           <li>Tweaking search algorithms</li>

1429)           <li>Adjust Elasticsearch</li>

1430)           <li>Enrich the data that is used to rank the search results</li>
1431)         </ul>
1432)       </li>
1433)       <li>Improving UX and UI (very important)<br />
1434)         <ul>
1435)           <li>Showing relevant knowledge</li>
1436)           <li>Design the navigation and information architecture</li>
1437)           <li>HTML5, CSS and Django development</li>
1438)         </ul>
1439)       </li>
1440)       <li>Review code and infrastructure<br />
1441)         <ul>
1442)           <li>Review code and fix bugs</li>
1443)           <li>Writing Django test cases</li>
1444)           <li>Linux configurations, automatizations</li>
1445)         </ul>
1446)       </li>
1447)       <li>Gather statistics over time and publish them<br />
1448)         <ul>
1449)           <li>Gather different kind of stats about Hidden Services</li>
1450)           <li>Publish these stats using HTTP REST API</li>
1451)           <li>Using this API show meaningful tables, charts and visualizations</li>
1452)         </ul>
1453)       </li>
1454)     </ol>
1455)     </li>

1456) <!--
1457)     <a id=""></a>
1458)     <li>
1459)     <b></b>
1460)     <br>

1461)     Language: <i>Python</i>

1462)     <br>
1463)     Likely Mentors: <i>Damian (atagar)</i>

1464)     <br><br>

1465)     <p>
1466) 
1467)     </p>
1468) 
1469)     <p>
1470) 
1471)     </p>
1472)     </li>
1473) -->
1474) 

1475)     <li>
1476)     <b>Bring up new ideas!</b>

1477)     <br>

1478)     Don't like any of these? Look at the <a

1479)     href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development

1480)     roadmap</a> for more ideas, or just try out Tor and Tor Browser,

1481)     and find out what you think needs fixing.

1482)     Some of the <a href="<spectree>proposals">current proposals</a>

1483)     might also be short on developers.
1484)     </li>

1485) 

1486)     </ol>

1487) 

1488)     <a id="OtherCoding"></a>
1489)     <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
1490)     <ol>
1491)     <li>Tor relays don't work well on Windows XP. On
1492)     Windows, Tor uses the standard <tt>select()</tt> system
1493)     call, which uses space in the non-page pool. This means
1494)     that a medium sized Tor relay will empty the non-page pool, <a

1495)     href="<wiki>doc/WindowsBufferProblems">causing

1496)     havoc and system crashes</a>. We should probably be using overlapped IO
1497)     instead. One solution would be to teach <a
1498)     href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
1499)     overlapped IO rather than select() on Windows, and then adapt Tor to
1500)     the new libevent interface. Christian King made a
1501)     <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
1502)     start</a> on this in the summer of 2007.</li>

1503) 

1504)     <li>We need a flexible simulator framework for studying end-to-end
1505)     traffic confirmation attacks. Many researchers have whipped up ad hoc
1506)     simulators to support their intuition either that the attacks work
1507)     really well or that some defense works great. Can we build a simulator
1508)     that's clearly documented and open enough that everybody knows it's
1509)     giving a reasonable answer? This will spur a lot of new research.
1510)     See the entry <a href="#Research">below</a> on confirmation attacks for
1511)     details on the research side of this task &mdash; who knows, when it's
1512)     done maybe you can help write a paper or three also.</li>

1513) 

1514)     <li>Tor 0.1.1.x and later include support for hardware crypto
1515)     accelerators via OpenSSL. It has been lightly tested and is
1516)     possibly very buggy.  We're looking for more rigorous testing,

1517)     performance analysis, and optimally, code fixes to OpenSSL and

1518)     Tor if needed.</li>

1519) 

1520)     <li>Write a <a
1521)     href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">fuzzer</a>
1522)     for Tor to discover security vulnerabilities. Determine if there
1523)     are good fuzzing frameworks out there for what we want. Win fame by

1524)     getting credit when we put out a new release because of you!</li>

1525) 

1526)     <li>Tor uses TCP for transport and TLS for link
1527)     encryption. This is nice and simple, but it means all cells
1528)     on a link are delayed when a single packet gets dropped, and
1529)     it means we can only reasonably support TCP streams. We have a <a

1530)     href="<page docs/faq>#TransportIPnotTCP">list

1531)     of reasons why we haven't shifted to UDP transport</a>, but it would
1532)     be great to see that list get shorter. We also have a proposed <a

1533)     href="<specblob>proposals/100-tor-spec-udp.txt">specification

1534)     for Tor and
1535)     UDP</a> &mdash; please let us know what's wrong with it.</li>

1536) 

1537)     <li>We're not that far from having IPv6 support for destination addresses
1538)     (at exit nodes). If you care strongly about IPv6, that's probably the
1539)     first place to start.</li>

1540) 

1541)     <li>We need a way to generate the website diagrams (for example, the "How
1542)     Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
1543)     from source, so we can translate them as UTF-8 text rather than edit
1544)     them by hand with Gimp. We might want to
1545)     integrate this as an wml file so translations are easy and images are
1546)     generated in multiple languages whenever we build the website.</li>

1547) 

1548)     <li>How can we make the various LiveCD/USB systems easier
1549)     to maintain, improve, and document?  One example is <a

1550)     href="https://tails.boum.org/">The Amnesic Incognito Live

1551)     System</a>.
1552)     </li>

1553) 

1554)     <li>
1555)     Another anti-censorship project is to try to make Tor
1556)     more scanning-resistant.  Right now, an adversary can identify <a

1557)     href="<specblob>proposals/125-bridges.txt">Tor bridges</a>

1558)     just by trying to connect to them, following the Tor protocol,
1559)     and seeing if they respond.  To solve this, bridges could <a
1560)     href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
1561)     webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
1562)     and not act like bridges until the user provides a bridge-specific key.
1563)     To start, check out Shane Pope's <a
1564)     href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
1565)     </li>

1566) 

1567)     </ol>

1568) 

1569)     <a id="Research"></a>
1570)     <h2><a class="anchor" href="#Research">Research</a></h2>
1571)     <ol>
1572)     <li>The "end-to-end traffic confirmation attack":
1573)     by watching traffic at Alice and at Bob, we can <a
1574)     href="http://freehaven.net/anonbib/#danezis:pet2004">compare
1575)     traffic signatures and become convinced that we're watching the same
1576)     stream</a>. So far Tor accepts this as a fact of life and assumes this
1577)     attack is trivial in all cases. First of all, is that actually true? How
1578)     much traffic of what sort of distribution is needed before the adversary
1579)     is confident he has won? Are there scenarios (e.g. not transmitting much)
1580)     that slow down the attack? Do some traffic padding or traffic shaping
1581)     schemes work better than others?</li>
1582)     <li>A related question is: Does running a relay/bridge provide additional
1583)     protection against these timing attacks? Can an external adversary that can't
1584)     see inside TLS links still recognize individual streams reliably?
1585)     Does the amount of traffic carried degrade this ability any? What if the
1586)     client-relay deliberately delayed upstream relayed traffic to create a queue
1587)     that could be used to mimic timings of client downstream traffic to make it
1588)     look like it was also relayed? This same queue could also be used for masking
1589)     timings in client upstream traffic with the techniques from <a
1590)     href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
1591)     but without the need for additional traffic. Would such an interleaving of
1592)     client upstream traffic obscure timings for external adversaries? Would the
1593)     strategies need to be adjusted for asymmetric links? For example, on
1594)     asymmetric links, is it actually possible to differentiate client traffic from
1595)     natural bursts due to their asymmetric capacity? Or is it easier than
1596)     symmetric links for some other reason?</li>
1597)     <li>Repeat Murdoch and Danezis's <a
1598)     href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
1599)     Oakland 05</a> on the current Tor network. See if you can learn why it
1600)     works well on some nodes and not well on others. (My theory is that the
1601)     fast nodes with spare capacity resist the attack better.) If that's true,
1602)     then experiment with the RelayBandwidthRate and RelayBandwidthBurst
1603)     options to run a relay that is used as a client while relaying the
1604)     attacker's traffic: as we crank down the RelayBandwidthRate, does the
1605)     attack get harder? What's the right ratio of RelayBandwidthRate to
1606)     actually capacity? Or is it a ratio at all? While we're at it, does a
1607)     much larger set of candidate relays increase the false positive rate
1608)     or other complexity for the attack? (The Tor network is now almost two
1609)     orders of magnitude larger than it was when they wrote their paper.) Be
1610)     sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
1611)     Clog the Queue</a> too.</li>
1612)     <li>The "routing zones attack": most of the literature thinks of
1613)     the network path between Alice and her entry node (and between the
1614)     exit node and Bob) as a single link on some graph. In practice,
1615)     though, the path traverses many autonomous systems (ASes), and <a
1616)     href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
1617)     that the same AS appears on both the entry path and the exit path</a>.
1618)     Unfortunately, to accurately predict whether a given Alice, entry,
1619)     exit, Bob quad will be dangerous, we need to download an entire Internet
1620)     routing zone and perform expensive operations on it. Are there practical
1621)     approximations, such as avoiding IP addresses in the same /8 network?</li>
1622)     <li>Other research questions regarding geographic diversity consider
1623)     the tradeoff between choosing an efficient circuit and choosing a random
1624)     circuit. Look at Stephen Rollyson's <a
1625)     href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
1626)     paper</a> on how to discard particularly slow choices without hurting
1627)     anonymity "too much". This line of reasoning needs more work and more
1628)     thinking, but it looks very promising.</li>
1629)     <li>Tor doesn't work very well when relays have asymmetric bandwidth
1630)     (e.g. cable or DSL). Because Tor has separate TCP connections between
1631)     each hop, if the incoming bytes are arriving just fine and the outgoing
1632)     bytes are all getting dropped on the floor, the TCP push-back mechanisms
1633)     don't really transmit this information back to the incoming streams.
1634)     Perhaps Tor should detect when it's dropping a lot of outgoing packets,
1635)     and rate-limit incoming streams to regulate this itself? I can imagine
1636)     a build-up and drop-off scheme where we pick a conservative rate-limit,
1637)     slowly increase it until we get lost packets, back off, repeat. We
1638)     need somebody who's good with networks to simulate this and help design
1639)     solutions; and/or we need to understand the extent of the performance
1640)     degradation, and use this as motivation to reconsider UDP transport.</li>
1641)     <li>A related topic is congestion control. Is our
1642)     current design sufficient once we have heavy use? Maybe
1643)     we should experiment with variable-sized windows rather
1644)     than fixed-size windows? That seemed to go well in an <a

1645)     href="http://www.psc.edu/index.php/hpn-ssh/638">ssh

1646)     throughput experiment</a>. We'll need to measure and tweak, and maybe
1647)     overhaul if the results are good.</li>
1648)     <li>Our censorship-resistance goals include preventing
1649)     an attacker who's looking at Tor traffic on the wire from <a
1650)     href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
1651)     it from normal SSL traffic</a>. Obviously we can't achieve perfect
1652)     steganography and still remain usable, but for a first step we'd like to
1653)     block any attacks that can win by observing only a few packets. One of
1654)     the remaining attacks we haven't examined much is that Tor cells are 512
1655)     bytes, so the traffic on the wire may well be a multiple of 512 bytes.
1656)     How much does the batching and overhead in TLS records blur this on the
1657)     wire? Do different buffer flushing strategies in Tor affect this? Could
1658)     a bit of padding help a lot, or is this an attack we must accept?</li>
1659)     <li>Tor circuits are built one hop at a time, so in theory we have the
1660)     ability to make some streams exit from the second hop, some from the
1661)     third, and so on. This seems nice because it breaks up the set of exiting
1662)     streams that a given relay can see. But if we want each stream to be safe,
1663)     the "shortest" path should be at least 3 hops long by our current logic, so
1664)     the rest will be even longer. We need to examine this performance / security
1665)     tradeoff.</li>
1666)     <li>It's not that hard to DoS Tor relays or directory authorities. Are client
1667)     puzzles the right answer? What other practical approaches are there? Bonus
1668)     if they're backward-compatible with the current Tor protocol.</li>
1669)     <li>Programs like <a

1670)     href="<page docs/torbutton/index>">Torbutton</a> aim to hide

1671)     your browser's UserAgent string by replacing it with a uniform answer for
1672)     every Tor user. That way the attacker can't splinter Tor's anonymity set
1673)     by looking at that header. It tries to pick a string that is commonly used
1674)     by non-Tor users too, so it doesn't stand out. Question one: how badly
1675)     do we hurt ourselves by periodically updating the version of Firefox
1676)     that Torbutton claims to be? If we update it too often, we splinter the
1677)     anonymity sets ourselves. If we don't update it often enough, then all the
1678)     Tor users stand out because they claim to be running a quite old version
1679)     of Firefox. The answer here probably depends on the Firefox versions seen
1680)     in the wild. Question two: periodically people ask us to cycle through N
1681)     UserAgent strings rather than stick with one. Does this approach help,
1682)     hurt, or not matter? Consider: cookies and recognizing Torbutton users
1683)     by their rotating UserAgents; malicious websites who only attack certain
1684)     browsers; and whether the answers to question one impact this answer.
1685)     </li>
1686)     <li>How many bridge relays do you need to know to maintain
1687)     reachability? We should measure the churn in our bridges. If there is
1688)     lots of churn, are there ways to keep bridge users more likely to stay
1689)     connected?
1690)     </li>
1691)     </ol>

1692) 

1693)     <p>
1694)     <a href="<page about/contact>">Let us know</a> if you've made progress on any
1695)     of these!
1696)     </p>
1697)   </div>
1698)   <!-- END MAINCOL -->
1699)   <div id = "sidecol">
1700) #include "side.wmi"
1701) #include "info.wmi"
1702)   </div>
1703)   <!-- END SIDECOL -->
1704) </div>
1705) <!-- END CONTENT -->