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

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

530)     href="https://gitweb.torproject.org/pluggable-transports/obfsproxy.git">code</a>,
531)     <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

532)     tracker</a>)</h3>

533) 

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

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

537)     </p>

538) 

539)     <a id="project-flash-proxy"></a>
540)     <h3><a href="https://crypto.stanford.edu/flashproxy/">Flash Proxy</a> (<a
541)     href="https://gitweb.torproject.org/flashproxy.git">code</a>, <a
542)     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
543)     tracker</a>)</h3>

544) 

545)     <p>
546)     Pluggable transport using proxies running in web browsers to defeat
547)     address-based blocking.
548)     </p>

549) 

550)     <a id="project-chutney"></a>
551)     <h3>Chutney (<a href="https://gitweb.torproject.org/chutney.git">code</a>,
552)     <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
553)     tracker</a>)</h3>
554) 
555)     <p>
556)     Integration test suite that spawns a local tor network, checking the
557)     interactions of its components.
558)     </p>
559) 

560)     <a id="project-shadow"></a>
561)     <h3><a href="https://shadow.cs.umn.edu/">Shadow</a> (<a
562)     href="https://github.com/shadow">code</a>, <a
563)     href="https://github.com/shadow/shadow/issues">bug
564)     tracker</a>)</h3>

565) 

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

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

572)     </p>

573) 

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

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

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

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

578)     tracker</a>)</h3>

579) 

580)     <p>

581)     Python controller library for scripts and controller applications using
582)     Tor.

583)     </p>

584) 

585)     <p>
586)     <b>Project Ideas:</b><br />
587)     <i><a href="#descriptor_parsing_in_go">Stem Descriptor Parsing in Go</a></i>
588)     </p>
589) 

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

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

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

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

594) 

595)     <p>
596)     Twisted-based asynchronous Tor control protocol implementation. Includes
597)     unit-tests, examples, state-tracking code and configuration abstraction.
598)     Used by OONI and APAF.
599)     </p>

600) 

601)     <p>
602)     <b>Project Ideas:</b><br />
603)     <i><a href="#txtorcon_use_txaio">Convert txtorcon to use txaio</a></i><br />
604)     <i><a href="#txtorcon_use_pytest">Convert txtorcon to py.test</a></i>
605)     </p>
606) 

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

609) 

610)     <p>
611)     tlsdate: secure parasitic rdate replacement
612)     </p>

613) 

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

621) 

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

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

626) 

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

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

632)     </p>

633) 

634)     <a id="project-atlas"></a>
635)     <h3><a href="https://atlas.torproject.org/">Atlas</a> (<a
636)     href="https://gitweb.torproject.org/atlas.git">code</a>)</h3>

637) 

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

641)     their past usage.

642)     </p>

643) 

644)     <p>

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

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

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

650)     </p>

651) 

652)     <a id="project-globe"></a>
653)     <h3><a href="http://globe.rndm.de/">Globe</a> (<a
654)     href="https://github.com/makepanic/globe">code</a>, <a
655)     href="https://github.com/makepanic/globe/issues">bug tracker</a>)</h3>
656) 
657)     <p>
658)     Globe is a web application that allows you to search for Tor relays and
659)     bridges. It gives you a detailed overview of properties and configurations
660)     of a relay or bridge.
661)     </p>
662) 

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

668) 

669)     <p>
670)     Compass is a web and command line application that filters and
671)     aggregates the Tor relays based on various attributes.
672)     </p>

673) 
674)     <a id="project-onionoo"></a>

675)     <h3><a href="https://onionoo.torproject.org/">Onionoo</a> (<a
676)     href="https://gitweb.torproject.org/onionoo.git">code</a>,
677)     <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>

678) 
679)     <p>
680)     Onionoo is a JSON based protocol to learn information about currently
681)     running Tor relays and bridges.
682)     </p>
683) 

684)     <a id="project-exitmap"></a>
685)     <h3><a href="http://www.cs.kau.se/philwint/spoiled_onions/">ExitMap</a> (<a
686)     href="https://github.com/NullHypothesis/exitmap">code</a>, <a
687)     href="https://github.com/NullHypothesis/exitmap/issues">bug tracker</a>)</h3>
688) 
689)     <p>

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

693)     Onions</a> research paper.
694)     </p>
695) 

696)     <p>
697)     <b>Project Ideas:</b><br />
698)     <i><a href="#exitmap_improvements">Exitmap Improvements</a></i>
699)     </p>
700) 

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

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

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

716)     href="https://gitweb.torproject.org/weather.git">code</a>, <a
717)     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
718)     tracker</a>)</h3>

719) 

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

726) 

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

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

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

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

732) 

733)     <p>
734)     E-mail autoresponder providing Tor's packages over SMTP. This has been
735)     relatively unchanged for quite a while.
736)     </p>

737) 

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

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

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

741)     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
742)     tracker</a>)</h3>

743) 

744)     <p>

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

746)     </p>

747) 

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

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

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

753) 

754)     <p>
755)     Backend bridge distributor, handling the various pools they're distributed
756)     in. This was actively developed until Fall of 2010.
757)     </p>

758) 
759)     <a id="project-ooni-probe"></a>

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

761)     href="https://gitweb.torproject.org/ooni-probe.git">code</a>, <a
762)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Ooni&order=priority">bug
763)     tracker</a>)</h3>
764) 
765)     <p>
766)     Censorship scanner, checking your local connection for blocked or modified
767)     content.
768)     </p>
769) 

770)     <a id="project-torps"></a>
771)     <h3>TorPS</a> (<a href="https://github.com/torps/torps">code</a>)</h3>
772) 
773)     <p>
774)     The Tor Path Simulator (TorPS) is a tool for efficiently simulating
775)     path selection in Tor. It chooses circuits and assigns user streams to
776)     those circuits in the same way that Tor does. TorPS is fast enough to
777)     perform thousands of simulations over periods of months.
778)     </p>
779) 

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

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

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

785) 

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

794) 
795)     <a id="project-tor2web"></a>
796)     <h3><a

797)     href="https://www.tor2web.org">Tor2web</a> (<a

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

807)     <a id="project-anonbib"></a>
808)     <h3><a
809)     href="http://freehaven.net/anonbib/">Anonymity Bibliography</a> (<a
810)     href="https://gitweb.torproject.org/anonbib.git">code</a>)</h3>
811) 
812)     <p>

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

816)     </p>
817) 

818)     <a id="Coding"></a>
819)     <a id="Summer"></a>

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

821) 

822)     <p>

823)     You may find some of these projects to be good ideas for <a href="<page

824)     about/gsoc>">Google Summer of Code</a>. We have labelled each idea with
825)     which of our <a href="<page about/corepeople>">core developers</a> would be
826)     good mentors. If one or more of these ideas looks promising to you, please
827)     <a href="<page about/contact>">contact us</a> to discuss your plans rather
828)     than sending blind applications. You may also want to propose your own
829)     project idea &mdash; which often results in the best applications.

830)     </p>

831) 

832)     <ol>

833) 

834)     <a id="improveHiddenServices"></a>
835)     <li>
836)     <b>Help improve Tor hidden services</b>
837)     <br>

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

839)     <br>

840)     Likely Mentors: <i>George (asn), David Goulet (dgoulet)</i>

841)     <br><br>

842)     <p>
843) We're working on a revamp of the entire Tor hidden service design to
844) improve the security and reliability of the hidden service system.
845)     </p>
846) 
847)     <p>
848) This is a big project: see

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

850) 224</a> for the latest design.  Are you interested in implementing some
851) part of that?
852)     </p>
853) 
854)     <p>
855) This is a very ambitious project, so we're deliberately not suggesting
856) particular sub-topics.  If you're interested in participating, try to
857) read and understand the <a

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

859) design</a> and the design proposal for the new design, and then talk to
860) us about what part you want to work on.
861)     </p>
862) 
863)     <p>
864) As part of the application process for this project, please contribute a
865) nontrivial patch to Tor -- ideally, one that will affect some part of
866) the codebase that you want to work on.
867)     </p>
868)     </li>
869) 

870)     <a id="exitmap_improvements"></a>
871)     <li>
872)     <b>Exitmap Improvements</b>
873)     <br>

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

875)     <br>
876)     Likely Mentors: <i>Philipp (phw)</i>

877)     <br><br>

878)     <p>
879) The Tor Project makes use of the Python tool <a
880) href="https://gitweb.torproject.org/user/phw/exitmap.git/">Exitmap</a> to
881) systematically scan for malicious and misbehaving exit relays.  Once such a
882) relay is found, it is assigned the BadExit flag which prevents clients from
883) selecting the relay as last hop in their circuit.
884)     </p>
885) 
886)     <p>
887) Exitmap supports scanning modules which implement a specific scan over
888) exit relays.  Examples are the DNS module which checks for DNS poisoning
889) or the patching check module which looks out for tampered file
890) downloads.
891)     </p>
892) 
893)     <p>
894) This project is meant to extend exitmap in several ways.  First, it
895) should be made fully autonomous.  That means that exitmap should be able
896) to run in the background, periodically fetch new relay descriptors, and
897) have a smart algorithm which keeps scanning all exit relays
898) periodically.  Second, exitmap should be able to emulate some user
899) interaction and dynamically "explore" the web in order to detect
900) tampering.  Third, unit tests should be added for existing and new code
901) in order to make the code base more robust.
902)     </p>
903)     </li>

904) 

905)     <a id="expand_nyx"></a>
906)     <li>
907)     <b>Expand Nyx</b>
908)     <br>

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

910)     <br>
911)     Likely Mentors: <i>Damian (atagar)</i>

912)     <br><br>

913)     <p>
914) Nyx (previously known as <a href="https://www.atagar.com/arm/">arm</a>) is an
915) ncurses monitor that provides Tor relay operators...
916)     </p>
917) 
918)     <ul>
919)       <li><a href="https://www.atagar.com/arm/images/screenshot_page1_full.png">bandwidth graphs and event log</a></li>
920)       <li><a href="https://www.atagar.com/arm/images/screenshot_page2_full.png">connections</a></li>
921)       <li><a href="https://www.atagar.com/arm/images/screenshot_page3_full.png">user's torrc</a></li>
922)       <li><a href="https://www.atagar.com/arm/images/screenshot_configPanel_full.png">config editor</a></li>
923)     </ul>
924) 
925)     <p>
926) Nyx is presently under development in preparation for its next release. If you
927) like python, terminals, and collaborating on an active codebase this just might
928) be the project for you!
929)     </p>
930) 
931)     <p>
932) Proposals should involve a grab-bag of moderately small improvements you'd like
933) to make. You're encouraged to brainstorm ideas of their own but here's a few to
934) get ya started...
935)     </p>
936) 
937)     <ul>
938)       <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>
939)       <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>
940)       <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>
941)       <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>

942)       <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>

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

944)       <li>... and more! Again, don't hesitate to propose ideas of your own.</li>
945)     </ul>
946) 
947)     <p>
948)     <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>
949)     </p>
950)     </li>
951) 

952)     <a id="descriptor_parsing_in_go"></a>
953)     <li>
954)     <b>Stem Descriptor Parsing in Go</b>
955)     <br>
956)     Language: <i>Go, Python</i>
957)     <br>
958)     Likely Mentors: <i>Damian (atagar), Philipp (phw)</i>
959)     <br><br>
960)     <p>
961)     Tor consists of two parts: the application and a distributed network of a
962)     few thousand volunteer relays. Information about these relays is public,
963)     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
964)     <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>...
965)     </p>
966) 
967)     <ul>
968)       <li><b><a href="https://stem.torproject.org/">Stem</a></b> (Python)</li>
969)       <li><b><a href="https://gitweb.torproject.org/metrics-lib.git/">Metrics-lib</a></b> (Java)</li>
970)       <li><b><a href="https://gitweb.torproject.org/user/phw/zoossh.git/">Zoossh</a></b> (Go)</li>
971)     </ul>
972) 
973)     <p>
974)     Stem is the most feature rich but slowest, and conversely Zoossh is fastest
975)     but limited. But what if Stem used CFFI bindings to do the heavy lifting in
976)     Go? Could we unify these libraries, getting the feature set of Stem with
977)     the performance of Zoossh?
978)     </p>
979) 
980)     <p>
981)     <b>Applicants should be familiar with both Python and Go. As part of your
982)     application for this project please write a demo CFFI binding for Stem as a
983)     proof of concept.</b> Bonus points if you <a
984)     href="https://stem.torproject.org/faq.html#how-do-i-get-started">get your
985)     hands wet by contributing patches</a>!
986)     </p>
987)     </li>
988) 

989)     <a id="txtorcon_use_txaio"></a>
990)     <li>
991)     <b>Convert txtorcon to use txaio</b>
992)     <br>
993)     Language: <i>Python, asyncio, Twisted</i>
994)     <br>
995)     Likely Mentors: <i>meejah</i>
996)     <br><br>
997)     <p>
998)     txtorcon is currently supports only Twisted users. Re-working txtorcon
999)     to use the txaio library would allow users to choose between Twisted and
1000)     asyncio for the client code.
1001)     </p>
1002) 
1003)     <p>
1004)     This would involve fairly extensive refactoring to txtorcon, as it
1005)     currently makes heavy use of @inlineCallbacks which doesn't work with
1006)     txaio. A prospective student should be very familiar with event-based
1007)     programming in general, and be familiar with one of Twisted or asyncio.
1008)     See also: https://github.com/meejah/txtorcon/issues/135
1009)     </p>
1010)     </li>
1011) 
1012)     <a id="txtorcon_use_pytest"></a>
1013)     <li>
1014)     <b>Convert txtorcon to py.test</b>
1015)     <br>
1016)     Language: <i>Python, Twisted</i>
1017)     <br>
1018)     Likely Mentors: <i>meejah</i>
1019)     <br><br>
1020)     <p>
1021)     Currently txtorcon uses the built-in "unittest" module, as well as
1022)     Twisted's Deferred-respecting extensions on top. However, meejah has
1023)     found py.test's "fixture" approach to be much more powerful in other
1024)     situations.
1025)     </p>
1026) 
1027)     <p>
1028)     This project would be to port at least part of txtorcon's test-suite to
1029)     use py.test style tests and fixtures and evaluate: are the tests easier
1030)     to read? are there fewer lines of code? If so, the rest of the suite
1031)     should be ported and txtorcon switched over to use py.test exclusively.
1032)     </p>
1033) 
1034)     <p>
1035)     As some of txtorcon's tests aren't very well-written, this would take a
1036)     prospective student who is very strong in unit-testing knowledge. As
1037)     txtorcon is event-based, familiarity with that style of programming
1038)     (preferrably with Twisted) is ideal.
1039)     See also: https://github.com/meejah/txtorcon/issues/136
1040)     </p>
1041)     </li>
1042) 

1043)     <a id="coniks_in_messenger"></a>
1044)     <li>
1045)     <b>Implement and Integrate CONIKS for Tor Messenger</b>
1046)     <br>

1047)     Language: <i>C, JavaScript</i>

1048)     <br>

1049)     Likely Mentors: <i>Marcela (masomel), Arlo (arlolra)</i>

1050)     <br><br>

1051)     <p>
1052) CONIKS is an end-user key management and verification system for end-to-end
1053) secure communication services, which improves upon existing key management
1054) systems by providing both strong security and better usability using a model
1055) called key transparency. CONIKS does this by requiring providers to manage
1056) tamper-evident, publicly-auditable key directories, which contain mappings from
1057) usernames to public keys, on behalf of their users. This design makes it easier
1058) for users (both "default" users and power users) to establish trust since they
1059) don't have to worry about or even see keys, but users also don't have to
1060) trust the provider to be well-behaved because the CONIKS client can run as
1061) part of the secure messaging app and automatically check that the service
1062) provider doesn’t map spurious keys to their users' usernames, and it can
1063) verify that observed name-to-key mappings are consistent with what other
1064) clients in the system are seeing. Unlike existing key transparency solutions,
1065) CONIKS also provides strong privacy guarantees by employing cryptographic
1066) primitives for robust data obfuscation.
1067)     </p>
1068) 
1069)     <p>
1070) The CONIKS system design, protocols, and proof-of-concept are described in
1071) great detail in the <a
1072) href="https://www.usenix.org/system/files/conference/usenixsecurity15/sec15-paper-melara.pdf">CONIKS
1073) research paper</a>, and basic reference implementations of a CONIKS key server
1074) and a CONIKS client are avialable on <a
1075) href="https://github.com/coniks-sys/coniks-ref-implementation">Github</a>.
1076)     </p>
1077) 
1078)     <p>
1079) This project has two main components: (1) designing and implementing a CONIKS
1080) key server tailored to Tor Messenger users, and (2) building a CONIKS client
1081) which integrates with the Tor Messenger client. One challenge the applicant
1082) will face is ensuring that the key server design is efficient and scalable for
1083) large volumes of users, concurrent traffic and guarantees this scalability even
1084) as Tor Messenger's user base grows. On the client side, the main challenges
1085) will be to focus on space efficiency as well as minimizing computational
1086) overhead when implementing the CONIKS consistency checks, and determining how
1087) to best communicate CONIKS consistency check results to users in the UI. Since
1088) Tor Messenger does not hand out online identities per se, as most online
1089) communication services do (like, say, Twitter, in which each user has a unique
1090) handle), the CONIKS key server for Tor Messenger will have to map usernames
1091) from third-party communication services to the encryption keys used in Tor
1092) Messenger. One additional important challenge that the applicant will have to
1093) help address is ensuring that each such third-party username remains unique in
1094) the Tor Messenger space and that such external, third-party identities are
1095) indeed controlled by the expected user of that third-party communication
1096) service.
1097)     </p>
1098) 
1099)     <p>
1100) Some design and implementation questions have been discussed in <a
1101) href="https://trac.torproject.org/projects/tor/ticket/17961">Ticket #17961</a>.
1102)     </p>
1103) 
1104)     <p>
1105) The applicant should have some familiarity with well-known crypto primitives
1106) and algorithms, as well as have a basic understanding of the key transparency
1107) model. Client side integration will require some basic use of JavaScript.
1108) Consider submitting a patch for <a
1109) href="https://github.com/arlolra/ctypes-otr/issues">one of the open key
1110) verification issues</a> as part of the application process.
1111)     </p>
1112)     </li>

1113) 
1114)     <a id="panopticlick"></a>
1115)     <li>
1116)     <b>Panopticlick</b>
1117)     <br>
1118)     Likely Mentors: <i>Georg (GeKo)</i>
1119)     <p>
1120) 
1121) The <a href="https://panopticlick.eff.org">Panopticlick project by the EFF</a>
1122) revolutionized how people think about <a
1123) href="https://panopticlick.eff.org/browser-uniqueness.pdf">browser
1124) fingerprinting</a>, both by developing tests and metrics to measure browser
1125) fingerprintability, and by crowdsourcing the evaluation and contribution of
1126) individual browser features to overall fingerprintability.
1127) 
1128)     </p>
1129)     <p>
1130) 
1131) Unfortunately, the way Panopticlick is designed <a
1132) href="https://blog.torproject.org/blog/effs-panopticlick-and-torbutton">makes
1133) it difficult</a> to evaluate defenses to browser fingerprinting, especially
1134) for browsers with a relatively small userbase such as Tor Browser. This is
1135) because any approach we take to reduce fingerprinting automatically makes our
1136) users more distinct from the previous users who submitted their fingerprint
1137) data to the EFF. Indeed, it is also impossible to ever expect that users of
1138) one browser will ever be able to blend in with users of another browser
1139) (Chrome users will always be distinguishable from Firefox users for example,
1140) based on feature set alone).
1141) 
1142)    </p>
1143)    <p>
1144) 
1145) To address this, we would like to have <a
1146) href="https://trac.torproject.org/projects/tor/ticket/6119">our own
1147) fingerprint test suite</a> to evaluate the fingerprintability of each browser
1148) feature for users running a specific Tor Browser version. There are also <a
1149) href="https://trac.torproject.org/projects/tor/query?keywords=~tbb-fingerprinting">additional
1150) fingerprinting tests</a> we can add beyond those deployed by Panopticlick.
1151)    </p>
1152)    <p>
1153) 
1154) For this project, the student would develop a website that users can
1155) voluntarily visit to test and record their Tor Browser fingerprint.  The user
1156) should get feedback on how she performed and the test results should be
1157) available in a machine readable format (e.g. JSON), broken down by Tor Browser
1158) version.  In a second step one could think about adding more sophisticated
1159) tests or supporting other browser vendors that might want to test the
1160) uniformity amongst their userbase as well. Of course, results from each
1161) browser would also need to be broken down by both browser implementation and
1162) version, so that results would only reflect the population of that specific
1163) implementation.
1164) 
1165)     </p>
1166)     </li>
1167) 

1168)     <a id="stegotorus"></a>
1169)     <li>
1170)     <b>Make Stegotorus deployment ready</b>
1171)     <br>
1172)     Language: <i>C++</i>
1173)     <br>
1174)     Likely Mentors: <i>vmon</i>
1175)     <br><br>
1176)     <p>
1177)     <a
1178)     href="https://github.com/TheTorProject/stegotorus/tree/master/src">Stegotorus</a>
1179)     is a PT framework which streamline the development stealthier pluggable
1180)     transport. An HTTP pluggable transport is already implemented in Stegotorus
1181)     framework and can be used when encrypted payloads are throttled and only
1182)     ephemeral connections are tolerated.
1183)     </p>
1184) 
1185)     <p>
1186)     The majority of work on Stegotorus is done and it can be deployed with a relatively minor improvements including:
1187)     </p>
1188) 
1189)     <ul>
1190)       <li><b>#8098 A config file file for Stegotorus</b>
1191)         <p>
1192)         Stegotorus needs many configuration settings specially on the bridge
1193)         side. This include also the configuration required by each steg module.
1194)         Currently the configuration is fed to Stegotorus as command line
1195)         arguments but a file like torrc is needed so all tweaking can be read
1196)         from there.
1197)         </p>
1198) 
1199)         <p><i>
1200)         Current Status and work needed to be done: The code for reading the
1201)         config file is written by SRI but it is not yet used in the Stegotorus
1202)         to read the config.
1203)         </i></p>
1204)       </li>
1205) 
1206)       <li><b>#8101 Debugging the transparent proxy</b>
1207)         <p>
1208)         Stegotorus http module uses other websites payload to hide and serve
1209)         censored traffic. As such it needs to decide if the request is
1210)         genuinely to the auxiliary website, in that case becomes a transparent
1211)         proxy and serves the website content as requested, or if the request is
1212)         actually a request to serve censored material which should be delivered
1213)         to steg modules.
1214)         </p>
1215) 
1216)         <p><i>
1217)         Current Status: This is completely implemented. However, the transparent proxy sometimes crashes and need to be triaged, debugged and fixed.
1218)         </i></p>
1219)       </li>
1220) 
1221)       <li><b>#11337 refactoring the steg module code</b>
1222)         <p>
1223)         The http steg module code, although not essentials to the core of the
1224)         Stegotorus. needs some improvement and clean up. The solution is to
1225)         refactor the steg modules as children of FileStegMod.
1226)         </p>
1227) 
1228)         <p><i>
1229)         Current status and work needed to be done: This has already been done
1230)         but still needs testing and refactoring before it can be reliably merge
1231)         to the master branch.
1232)         </i></p>
1233)       </li>
1234) 
1235)       <li><b>#8089 Adding Elligator to Stegotorus handshake and test</b>
1236)         <p>
1237)         The current Stegotorus handshake is distinguishable from random byte
1238)         string, which can be used to flag and detect Stegotorus traffic
1239)         deterministically and need to be implemented similar to
1240)         ScrambleSuite. Also because the capacity of client to server channel
1241)         might be slim depending on the choice of steg module it is desirable
1242)         to be implemented using Elliptic curve crypto. Hence, Elligator
1243)         protocol is ideal solution for this situation. All we need is to replace Stegotorus handshake by Elligator.
1244)         </p>
1245) 
1246)         <p><i>
1247)         Current Status and work needed to be done: Elligator handshake code is
1248)         included in stegotorus code base, it is only needed to be called by
1249)         instead of the current handshake and be tested.
1250)         </i></p>
1251)       </li>
1252) 
1253)       <li><b>Make Stegotorus memory safe by using shared pointers</b>
1254)         <p>
1255)         Stegotorus has large code base and it is not written in a memory safe
1256)         languages. To facilitate its audit, we need to replace (almost all) use
1257)         of pointers to shared pointers.
1258)         </p>
1259) 
1260)         <p><i>
1261)         Current Status: No progress has not been done.
1262)         </i></p>
1263)       </li>
1264) 
1265)       <li><b>Security Audit and writing more unit test</b>
1266)         <p>
1267)         To be able to deploy Stegotorus for real world use we need to audit the
1268)         code and write more unit test covering new aspects of the Stegotorus
1269)         (new http transport, proxy server, Elligator handshake)
1270)         </p>
1271) 
1272)         <p><i>
1273)         Current Status: No progress has been done.
1274)         </i></p>
1275)       </li>
1276) 
1277)       <li><b>SRI branch merging</b>
1278)         <p>
1279)         Stegotorus has been forked from the initial development from SRI. Now
1280)         that SRI is hosting Stegotorus publicly it is desirable to merge the
1281)         two branches so we can benefit from both developments.
1282)         </p>
1283) 
1284)         <p><i>
1285)         Current Status: No progress has been done.
1286)         </i></p>
1287)       </li>
1288) 
1289)       <li><b>#8099 deterministic build</b>
1290)         <p>
1291)         To make deterministic build possible we need to build many of
1292)         Stegotorus dependency from scratch. Boost library is a a huge
1293)         dependency for Stegotorus to access the file system. As we are only
1294)         planning to deploy Stegotorus bridges on Linux machines we can simplify
1295)         such access without that dependency. By dropping such dependency, it
1296)         should be straight forward to have deterministic build for Stegotorus.
1297)         </p>
1298) 
1299)         <p><i>
1300)         Current Status: No progress has been done.
1301)         </i></p>
1302)       </li>
1303)     </ul>
1304)     </li>
1305) 

1306)     <a id="letsEncryptClient"></a>
1307)     <li>
1308)     <b>Expand the OS and Server Support of the Let's Encrypt Client</b>
1309)     <br>
1310)     Language: <i>Python, Bash</i>
1311)     <br>
1312)     Likely Mentors: <i>Brad Warren (bmw)</i>
1313)     <br><br>
1314)     <p>
1315)     <a href="https://letsencrypt.org/">Let's Encrypt</a> is a free and open
1316)     certificate authority that allows its users to setup HTTPS on their web
1317)     server in a matter of seconds. The project uses a new protocol called ACME
1318)     to automatically perform domain validation and certificate issuance.
1319)     </p>
1320) 
1321)     <p>
1322)     The Let's Encrypt client currently works on most Unix-like OSes and is
1323)     able to automatically set up HTTPS on many Apache configurations. The
1324)     purpose of this project is to expand Let's Encrypt support to new
1325)     systems.
1326)     </p>
1327) 
1328)     <p>
1329)     Potential targets include:
1330)     </p>
1331) 
1332)     <ul>
1333)       <li>Better OS X support including a port or Homebrew package</li>
1334)       <li>A Let's Encrypt client for Windows / IIS</li>
1335)       <li>Handling of more obscure Apache configurations</li>
1336)       <li>Automated HTTPS configuration for other web servers such as Nginx or lighttpd</li>
1337)       <li>Improved support people using shared hosting who are unable to use the full Let's Encrypt client on their server</li>
1338)     </ul>
1339)     </li>
1340) 

1341)     <a id="ahmiaSearch"></a>
1342)     <li>
1343)     <b>Ahmia - Hidden Service Search</b>
1344)     <br>
1345)     Language: <i>Python, Django</i>
1346)     <br>
1347)     Likely Mentors: <i>Juha Nurmi (numes), George (asn)</i>
1348)     <br><br>
1349)     <p>
1350)     Ahmia is open-source search engine software for Tor hidden service deep
1351)     dark web sites. You can test the running search engine at ahmia.fi. For
1352)     more information see our <a
1353)     href="https://blog.torproject.org/category/tags/ahmiafi">blog post about
1354)     Ahmia's GSoC2014 development</a>.
1355)     </p>
1356) 
1357)     <p>
1358)     Ahmia is a working search engine that indexes, searches, and catalogs
1359)     content published on Tor Hidden Services. Furthermore, it is an environment
1360)     to share meaningful insights, statistics, insights, and news about the Tor
1361)     network itself. In this context, there is a lot of work to do.
1362)     </p>
1363) 
1364)     <p>
1365)     The Ahmia web service is written using the Django web framework. As a
1366)     result, the server-side language is Python. On the client-side, most of the
1367)     pages are plain HTML. There are some pages that require JavaScript, but the
1368)     search itself works without client-side JavaScript.
1369)     </p>
1370) 
1371)     <p>
1372)     There are several possible directions for this project, including...
1373)     </p>
1374) 
1375)     <ol>
1376)       <li>Improving the search results (very important)<br />
1377)         <ul>
1378)           <li>Tweaking search algorithms</li>

1379)           <li>Adjust Elasticsearch</li>

1380)           <li>Enrich the data that is used to rank the search results</li>
1381)         </ul>
1382)       </li>
1383)       <li>Improving UX and UI (very important)<br />
1384)         <ul>
1385)           <li>Showing relevant knowledge</li>
1386)           <li>Design the navigation and information architecture</li>
1387)           <li>HTML5, CSS and Django development</li>
1388)         </ul>
1389)       </li>
1390)       <li>Review code and infrastructure<br />
1391)         <ul>
1392)           <li>Review code and fix bugs</li>
1393)           <li>Writing Django test cases</li>
1394)           <li>Linux configurations, automatizations</li>
1395)         </ul>
1396)       </li>
1397)       <li>Gather statistics over time and publish them<br />
1398)         <ul>
1399)           <li>Gather different kind of stats about Hidden Services</li>
1400)           <li>Publish these stats using HTTP REST API</li>
1401)           <li>Using this API show meaningful tables, charts and visualizations</li>
1402)         </ul>
1403)       </li>
1404)     </ol>
1405)     </li>

1406) 
1407)     <a id="ipHijacking"></a>
1408)     <li>
1409)     <b>IP hijacking detection for the Tor Network</b>
1410)     <br>
1411)     Likely Mentors: <i>Aaron Gibson (aagbsn)</i>
1412)     <br><br>
1413)     <p>
1414)     <a href="https://en.wikipedia.org/wiki/IP_hijacking">IP hijacking</a>
1415)     occurs when a bad actor creates false routing information to redirect
1416)     Internet traffic to or through themselves. This activity is straightforward
1417)     to detect, because the Internet routing tables are public information, but
1418)     currently there are no public services that monitor the Tor network. The
1419)     Tor Network is a dynamic set of relays, so monitoring must be Tor-aware in
1420)     order to keep the set of monitored relays accurate. Additionally, consensus
1421)     archives and historical Internet routing table snapshots are publicly
1422)     available, and this analysis can be performed retroactively.
1423)     </p>
1424) 
1425)     <p>
1426)     The implications of IP hijacking are that Tor traffic can be redirected
1427)     through a network that an attacker controls, even if the attacker does not
1428)     normally have this capability - i.e. they are not in the network path. For
1429)     example, an adversary could hijack the prefix of a Tor Guard relay, in
1430)     order to learn who its clients are, or hijack a Tor Exit relay to tamper
1431)     with requests or name resolution.
1432)     </p>
1433) 
1434)     <p>
1435)     This project comprises building a service that compares network prefixes of
1436)     relays in the consensus with present and historic routing table snapshots
1437)     from looking glass services such as <a
1438)     href="http://routeviews.org">Routeviews</a>, or aggregators such as <a
1439)     href="https://bgpstream.caida.org">Caida BGPStream</a> and then issues
1440)     email alerts to the contact-info in the relay descriptor and a mailing
1441)     list. Network operators are responsive to route injections, and these
1442)     alerts can be used to notify network operators to take immediate action, as
1443)     well as collect information about the occurrence of these type of attacks.
1444)     </p>
1445)     </li>

1446) 
1447)     <a id="tailsServer"></a>
1448)     <li>
1449)     <b>Tails server: Self-hosted services behind Tails-powered Tor hidden services</b>
1450)     <br>
1451)     Likely Mentors: <i>anonym, George (asn)</i>
1452)     <p>Let's talk about group collaboration, communication and data sharing
1453)     infrastructure, such as chat servers, wikis, or file repositories.</p>
1454)     <p>Hosting such data and infrastructure <b>in the cloud</b> generally
1455)     implies to trust the service providers not to disclose content, usage or
1456)     users location information to third-parties. Hence, there are many threat
1457)     models in which cloud hosting is not suitable.</p>
1458)     <p>Tor partly answers the <b>users location</b> part; this is great, but
1459)     <b>content</b> is left unprotected.</p>
1460)     <p>There are two main ways to protect such content: either to encrypt it
1461)     client-side (<b>security by design</b>), or to avoid putting it into
1462)     untrusted hands in the first place.</p>
1463)     <p>Cloud solutions that offer security by design are rare and generally
1464)     not mature yet. The <b>Tails server</b> project is about exploring the
1465)     other side of the alternative: avoiding to put private data into
1466)     untrusted hands in the first place.</p>
1467)     <p>This is made possible thanks to Tor hidden services, that allow users
1468)     to offer location-hidden services, and make self-hosting possible in
1469)     many threat models. Self-hosting has its own lot of problems, however,
1470)     particularly in contexts where the physical security of the hosting
1471)     place is not assured. Combining Tor hidden services with Tails'
1472)     amnesia property and limited support for persistent encrypted data
1473)     allows to protect content, to a great degree, even in such contexts.</p>
1474)     <p>In short, setting up a new Tails server would be done by:</p>
1475) 
1476)     <ol style="list-style-type: decimal">
1477)       <li>Alice plugs a USB stick into a running desktop Tails system.</li>
1478)       <li>Alice uses a GUI to easily configure the needed services.</li>
1479)       <li>Alice unplugs the USB stick, that now contains encrypted services
1480)       configuration and data storage space.</li>
1481)       <li>Alice plugs that USB stick (and possibly a Tails Live CD) into the
1482)       old laptop that was dedicated to run Tails server.</li>
1483)       <li>Once booted, Alice enters the encryption passphrase either
1484)       directly using the keyboard or through a web interface listening on the
1485)       local network.</li>
1486)       <li>Then, Bob can use the configured services once he gets a hold on
1487)       the hidden service address. (The <b>petname system for Tor hidden
1488)       services</b> project would be very complementary to this one, by the
1489)       way.)</li>
1490)     </ol>
1491) 
1492)     <p>Tails server should content itself with hardware that is a bit old
1493)     (such as a PIII-450 laptop with 256MB of RAM) and/or half broken (e.g.
1494)     non-functional hard-disk, screen or keyboard).</p>
1495)     <p>The challenges behind this project are:</p>
1496) 
1497)     <ul>
1498)       <li>Design and write the services configuration GUI [keywords: edit
1499)       configuration files, upgrade between major Debian versions,
1500)       debconf].</li>
1501)       <li>How to create the hidden service key? [keywords: Vidalia, control
1502)       protocol].</li>
1503)       <li>Adapt the Tails boot process to allow switching to &quot;server
1504)       mode&quot; when appropriate.</li>
1505)       <li>Add support, to the Tails persistence setup process, for asking an
1506)       encryption passphrase without X, and possibly with a broken keyboard
1507)       and/or screen [keywords: local network, SSL/TLS?, certificate?].</li>
1508)     </ul>
1509) 
1510)     <p>This project can easily grow quite large, so the first task would
1511)     probably be to clarify what it would need to get an initial (minimal
1512)     but working) implementation ready to be shipped to users.</p>
1513)     <p>This project does not require to be an expert in one specific field,
1514)     but it requires to be experienced and at ease with a large scope of
1515)     software development tools, processes, and operating system knowledge.</p>
1516)     <p>Undertaking this project requires in-depth knowledge of Debian-like
1517)     systems (self-test: do the "dpkg conffile" and "debconf preseeding"
1518)     words sound new to your ear?); the Debian Live persistence system
1519)     being written in shell, being at ease with robust shell scripting is
1520)     a must; to end with, at least two pieces of software need to be
1521)     written from scratch (a GUI and a webapp): the preferred languages for
1522)     these tasks would be Python and Perl. Using Behaviour Driven
1523)     Development methods to convey expectations and acceptance criteria
1524)     would be most welcome.</p>
1525)     <p>For more information see https://tails.boum.org/todo/server_edition/</p>
1526)     </li>
1527) 

1528) <!--
1529)     <a id=""></a>
1530)     <li>
1531)     <b></b>
1532)     <br>

1533)     Language: <i>Python</i>

1534)     <br>
1535)     Likely Mentors: <i>Damian (atagar)</i>

1536)     <br><br>

1537)     <p>
1538) 
1539)     </p>
1540) 
1541)     <p>
1542) 
1543)     </p>
1544)     </li>
1545) -->
1546) 

1547)     <li>
1548)     <b>Bring up new ideas!</b>

1549)     <br>

1550)     Don't like any of these? Look at the <a

1551)     href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development

1552)     roadmap</a> for more ideas, or just try out Tor and Tor Browser,

1553)     and find out what you think needs fixing.

1554)     Some of the <a href="<spectree>proposals">current proposals</a>

1555)     might also be short on developers.
1556)     </li>

1557) 

1558)     </ol>

1559) 

1560)     <a id="OtherCoding"></a>
1561)     <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
1562)     <ol>
1563)     <li>Tor relays don't work well on Windows XP. On
1564)     Windows, Tor uses the standard <tt>select()</tt> system
1565)     call, which uses space in the non-page pool. This means
1566)     that a medium sized Tor relay will empty the non-page pool, <a

1567)     href="<wiki>doc/WindowsBufferProblems">causing

1568)     havoc and system crashes</a>. We should probably be using overlapped IO
1569)     instead. One solution would be to teach <a
1570)     href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
1571)     overlapped IO rather than select() on Windows, and then adapt Tor to
1572)     the new libevent interface. Christian King made a
1573)     <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
1574)     start</a> on this in the summer of 2007.</li>

1575) 

1576)     <li>We need a flexible simulator framework for studying end-to-end
1577)     traffic confirmation attacks. Many researchers have whipped up ad hoc
1578)     simulators to support their intuition either that the attacks work
1579)     really well or that some defense works great. Can we build a simulator
1580)     that's clearly documented and open enough that everybody knows it's
1581)     giving a reasonable answer? This will spur a lot of new research.
1582)     See the entry <a href="#Research">below</a> on confirmation attacks for
1583)     details on the research side of this task &mdash; who knows, when it's
1584)     done maybe you can help write a paper or three also.</li>

1585) 

1586)     <li>Tor 0.1.1.x and later include support for hardware crypto
1587)     accelerators via OpenSSL. It has been lightly tested and is
1588)     possibly very buggy.  We're looking for more rigorous testing,

1589)     performance analysis, and optimally, code fixes to OpenSSL and

1590)     Tor if needed.</li>

1591) 

1592)     <li>Write a <a
1593)     href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">fuzzer</a>
1594)     for Tor to discover security vulnerabilities. Determine if there
1595)     are good fuzzing frameworks out there for what we want. Win fame by

1596)     getting credit when we put out a new release because of you!</li>

1597) 

1598)     <li>Tor uses TCP for transport and TLS for link
1599)     encryption. This is nice and simple, but it means all cells
1600)     on a link are delayed when a single packet gets dropped, and
1601)     it means we can only reasonably support TCP streams. We have a <a

1602)     href="<page docs/faq>#TransportIPnotTCP">list

1603)     of reasons why we haven't shifted to UDP transport</a>, but it would
1604)     be great to see that list get shorter. We also have a proposed <a

1605)     href="<specblob>proposals/100-tor-spec-udp.txt">specification

1606)     for Tor and
1607)     UDP</a> &mdash; please let us know what's wrong with it.</li>

1608) 

1609)     <li>We're not that far from having IPv6 support for destination addresses
1610)     (at exit nodes). If you care strongly about IPv6, that's probably the
1611)     first place to start.</li>

1612) 

1613)     <li>We need a way to generate the website diagrams (for example, the "How
1614)     Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
1615)     from source, so we can translate them as UTF-8 text rather than edit
1616)     them by hand with Gimp. We might want to
1617)     integrate this as an wml file so translations are easy and images are
1618)     generated in multiple languages whenever we build the website.</li>

1619) 

1620)     <li>How can we make the various LiveCD/USB systems easier
1621)     to maintain, improve, and document?  One example is <a

1622)     href="https://tails.boum.org/">The Amnesic Incognito Live

1623)     System</a>.
1624)     </li>

1625) 

1626)     <li>
1627)     Another anti-censorship project is to try to make Tor
1628)     more scanning-resistant.  Right now, an adversary can identify <a

1629)     href="<specblob>proposals/125-bridges.txt">Tor bridges</a>

1630)     just by trying to connect to them, following the Tor protocol,
1631)     and seeing if they respond.  To solve this, bridges could <a
1632)     href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
1633)     webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
1634)     and not act like bridges until the user provides a bridge-specific key.
1635)     To start, check out Shane Pope's <a
1636)     href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
1637)     </li>

1638) 

1639)     </ol>

1640) 

1641)     <a id="Research"></a>
1642)     <h2><a class="anchor" href="#Research">Research</a></h2>
1643)     <ol>
1644)     <li>The "end-to-end traffic confirmation attack":
1645)     by watching traffic at Alice and at Bob, we can <a
1646)     href="http://freehaven.net/anonbib/#danezis:pet2004">compare
1647)     traffic signatures and become convinced that we're watching the same
1648)     stream</a>. So far Tor accepts this as a fact of life and assumes this
1649)     attack is trivial in all cases. First of all, is that actually true? How
1650)     much traffic of what sort of distribution is needed before the adversary
1651)     is confident he has won? Are there scenarios (e.g. not transmitting much)
1652)     that slow down the attack? Do some traffic padding or traffic shaping
1653)     schemes work better than others?</li>
1654)     <li>A related question is: Does running a relay/bridge provide additional
1655)     protection against these timing attacks? Can an external adversary that can't
1656)     see inside TLS links still recognize individual streams reliably?
1657)     Does the amount of traffic carried degrade this ability any? What if the
1658)     client-relay deliberately delayed upstream relayed traffic to create a queue
1659)     that could be used to mimic timings of client downstream traffic to make it
1660)     look like it was also relayed? This same queue could also be used for masking
1661)     timings in client upstream traffic with the techniques from <a
1662)     href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
1663)     but without the need for additional traffic. Would such an interleaving of
1664)     client upstream traffic obscure timings for external adversaries? Would the
1665)     strategies need to be adjusted for asymmetric links? For example, on
1666)     asymmetric links, is it actually possible to differentiate client traffic from
1667)     natural bursts due to their asymmetric capacity? Or is it easier than
1668)     symmetric links for some other reason?</li>
1669)     <li>Repeat Murdoch and Danezis's <a
1670)     href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
1671)     Oakland 05</a> on the current Tor network. See if you can learn why it
1672)     works well on some nodes and not well on others. (My theory is that the
1673)     fast nodes with spare capacity resist the attack better.) If that's true,
1674)     then experiment with the RelayBandwidthRate and RelayBandwidthBurst
1675)     options to run a relay that is used as a client while relaying the
1676)     attacker's traffic: as we crank down the RelayBandwidthRate, does the
1677)     attack get harder? What's the right ratio of RelayBandwidthRate to
1678)     actually capacity? Or is it a ratio at all? While we're at it, does a
1679)     much larger set of candidate relays increase the false positive rate
1680)     or other complexity for the attack? (The Tor network is now almost two
1681)     orders of magnitude larger than it was when they wrote their paper.) Be
1682)     sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
1683)     Clog the Queue</a> too.</li>
1684)     <li>The "routing zones attack": most of the literature thinks of
1685)     the network path between Alice and her entry node (and between the
1686)     exit node and Bob) as a single link on some graph. In practice,
1687)     though, the path traverses many autonomous systems (ASes), and <a
1688)     href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
1689)     that the same AS appears on both the entry path and the exit path</a>.
1690)     Unfortunately, to accurately predict whether a given Alice, entry,
1691)     exit, Bob quad will be dangerous, we need to download an entire Internet
1692)     routing zone and perform expensive operations on it. Are there practical
1693)     approximations, such as avoiding IP addresses in the same /8 network?</li>
1694)     <li>Other research questions regarding geographic diversity consider
1695)     the tradeoff between choosing an efficient circuit and choosing a random
1696)     circuit. Look at Stephen Rollyson's <a
1697)     href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
1698)     paper</a> on how to discard particularly slow choices without hurting
1699)     anonymity "too much". This line of reasoning needs more work and more
1700)     thinking, but it looks very promising.</li>
1701)     <li>Tor doesn't work very well when relays have asymmetric bandwidth
1702)     (e.g. cable or DSL). Because Tor has separate TCP connections between
1703)     each hop, if the incoming bytes are arriving just fine and the outgoing
1704)     bytes are all getting dropped on the floor, the TCP push-back mechanisms
1705)     don't really transmit this information back to the incoming streams.
1706)     Perhaps Tor should detect when it's dropping a lot of outgoing packets,
1707)     and rate-limit incoming streams to regulate this itself? I can imagine
1708)     a build-up and drop-off scheme where we pick a conservative rate-limit,
1709)     slowly increase it until we get lost packets, back off, repeat. We
1710)     need somebody who's good with networks to simulate this and help design
1711)     solutions; and/or we need to understand the extent of the performance
1712)     degradation, and use this as motivation to reconsider UDP transport.</li>
1713)     <li>A related topic is congestion control. Is our
1714)     current design sufficient once we have heavy use? Maybe
1715)     we should experiment with variable-sized windows rather
1716)     than fixed-size windows? That seemed to go well in an <a

1717)     href="http://www.psc.edu/index.php/hpn-ssh/638">ssh

1718)     throughput experiment</a>. We'll need to measure and tweak, and maybe
1719)     overhaul if the results are good.</li>
1720)     <li>Our censorship-resistance goals include preventing
1721)     an attacker who's looking at Tor traffic on the wire from <a
1722)     href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
1723)     it from normal SSL traffic</a>. Obviously we can't achieve perfect
1724)     steganography and still remain usable, but for a first step we'd like to
1725)     block any attacks that can win by observing only a few packets. One of
1726)     the remaining attacks we haven't examined much is that Tor cells are 512
1727)     bytes, so the traffic on the wire may well be a multiple of 512 bytes.
1728)     How much does the batching and overhead in TLS records blur this on the
1729)     wire? Do different buffer flushing strategies in Tor affect this? Could
1730)     a bit of padding help a lot, or is this an attack we must accept?</li>
1731)     <li>Tor circuits are built one hop at a time, so in theory we have the
1732)     ability to make some streams exit from the second hop, some from the
1733)     third, and so on. This seems nice because it breaks up the set of exiting
1734)     streams that a given relay can see. But if we want each stream to be safe,
1735)     the "shortest" path should be at least 3 hops long by our current logic, so
1736)     the rest will be even longer. We need to examine this performance / security
1737)     tradeoff.</li>
1738)     <li>It's not that hard to DoS Tor relays or directory authorities. Are client
1739)     puzzles the right answer? What other practical approaches are there? Bonus
1740)     if they're backward-compatible with the current Tor protocol.</li>
1741)     <li>Programs like <a

1742)     href="<page docs/torbutton/index>">Torbutton</a> aim to hide

1743)     your browser's UserAgent string by replacing it with a uniform answer for
1744)     every Tor user. That way the attacker can't splinter Tor's anonymity set
1745)     by looking at that header. It tries to pick a string that is commonly used
1746)     by non-Tor users too, so it doesn't stand out. Question one: how badly
1747)     do we hurt ourselves by periodically updating the version of Firefox
1748)     that Torbutton claims to be? If we update it too often, we splinter the
1749)     anonymity sets ourselves. If we don't update it often enough, then all the
1750)     Tor users stand out because they claim to be running a quite old version
1751)     of Firefox. The answer here probably depends on the Firefox versions seen
1752)     in the wild. Question two: periodically people ask us to cycle through N
1753)     UserAgent strings rather than stick with one. Does this approach help,
1754)     hurt, or not matter? Consider: cookies and recognizing Torbutton users
1755)     by their rotating UserAgents; malicious websites who only attack certain
1756)     browsers; and whether the answers to question one impact this answer.
1757)     </li>
1758)     <li>How many bridge relays do you need to know to maintain
1759)     reachability? We should measure the churn in our bridges. If there is
1760)     lots of churn, are there ways to keep bridge users more likely to stay
1761)     connected?
1762)     </li>
1763)     </ol>

1764) 

1765)     <p>
1766)     <a href="<page about/contact>">Let us know</a> if you've made progress on any
1767)     of these!
1768)     </p>
1769)   </div>
1770)   <!-- END MAINCOL -->
1771)   <div id = "sidecol">
1772) #include "side.wmi"
1773) #include "info.wmi"
1774)   </div>
1775)   <!-- END SIDECOL -->
1776) </div>
1777) <!-- END CONTENT -->