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volunteer.html      4) 

en/volunteer.wml    5) #include "head.wmi" TITLE="Tor: Volunteer"

volunteer.html      6) 
volunteer.html      7) <div class="main-column">
volunteer.html      8) 
volunteer.html      9) <!-- PUT CONTENT AFTER THIS TAG -->

en/volunteer.wml   10) <h2>A few things everyone can do now:</h2>

volunteer.html     11) <ol>

en/volunteer.wml   12) <li>Please consider <a href="<page docs/tor-doc-relay>">running
en/volunteer.wml   13) a relay</a> to help the Tor network grow.</li>
en/volunteer.wml   14) <li>Tell your friends! Get them to run relays. Get them to run hidden

volunteer.html     15) services. Get them to tell their friends.</li>

en/volunteer.wml   16) <li>If you like Tor's goals, please <a href="<page donate>">take a moment
en/volunteer.wml   17) to donate to support further Tor development</a>. We're also looking
en/volunteer.wml   18) for more sponsors &mdash; if you know any companies, NGOs, agencies,
en/volunteer.wml   19) or other organizations that want anonymity / privacy / communications
en/volunteer.wml   20) security, let them know about us.</li>
en/volunteer.wml   21) <li>We're looking for more <a href="<page torusers>">good examples of Tor
en/volunteer.wml   22) users and Tor use cases</a>. If you use Tor for a scenario or purpose not
en/volunteer.wml   23) yet described on that page, and you're comfortable sharing it with us,
en/volunteer.wml   24) we'd love to hear from you.</li>

volunteer.html     25) </ol>
volunteer.html     26) 

en/volunteer.wml   27) <a id="Usability"></a>

en/volunteer.wml   28) <h2><a class="anchor" href="#Usability">Supporting Applications</a></h2>

volunteer.html     29) <ol>

en/volunteer.wml   30) <li>We need more and better ways to intercept DNS requests so they don't "leak" their

en/volunteer.wml   31) request to a local observer while we're trying to be anonymous. (This
en/volunteer.wml   32) happens because the application does the DNS resolve before going to
en/volunteer.wml   33) the SOCKS proxy.)</li>

en/volunteer.wml   34) <li>Tsocks/dsocks items:

en/volunteer.wml   35) <ul>
en/volunteer.wml   36) <li>We need to <a

en/volunteer.wml   37) href="https://wiki.torproject.org/noreply/TheOnionRouter/TSocksPatches">apply

en/volunteer.wml   38) all our tsocks patches</a> and maintain a new fork. We'll host it if
en/volunteer.wml   39) you want.</li>
en/volunteer.wml   40) <li>We should patch Dug Song's "dsocks" program to use Tor's
en/volunteer.wml   41) <i>mapaddress</i> commands from the controller interface, so we
en/volunteer.wml   42) don't waste a whole round-trip inside Tor doing the resolve before
en/volunteer.wml   43) connecting.</li>
en/volunteer.wml   44) <li>We need to make our <i>torify</i> script detect which of tsocks or
en/volunteer.wml   45) dsocks is installed, and call them appropriately. This probably means
en/volunteer.wml   46) unifying their interfaces, and might involve sharing code between them
en/volunteer.wml   47) or discarding one entirely.</li>
en/volunteer.wml   48) </ul>

en/volunteer.wml   49) </li>

en/volunteer.wml   50) <li>People running relays tell us they want to have one BandwidthRate

en/volunteer.wml   51) during some part of the day, and a different BandwidthRate at other
en/volunteer.wml   52) parts of the day. Rather than coding this inside Tor, we should have a
en/volunteer.wml   53) little script that speaks via the <a href="<page gui/index>">Tor
en/volunteer.wml   54) Controller Interface</a>, and does a setconf to change the bandwidth

en/volunteer.wml   55) rate. There is one for Unix and Mac already (it uses bash and cron),

en/volunteer.wml   56) but Windows users still need a solution.

en/volunteer.wml   57) </li>

volunteer.html     58) <li>Speaking of geolocation data, somebody should draw a map of the Earth

en/volunteer.wml   59) with a pin-point for each Tor relay. Bonus points if it updates as the

en/volunteer.wml   60) network grows and changes. Unfortunately, the easy ways to do this involve
en/volunteer.wml   61) sending all the data to Google and having them draw the map for you. How
en/volunteer.wml   62) much does this impact privacy, and do we have any other good options?</li>

volunteer.html     63) </ol>
volunteer.html     64) 

en/volunteer.wml   65) <a id="Advocacy"></a>

en/volunteer.wml   66) <h2><a class="anchor" href="#Advocacy">Advocacy</a></h2>
en/volunteer.wml   67) <ol>
en/volunteer.wml   68) <li>Create a community logo under a Creative Commons license that all can use and modify</li>
en/volunteer.wml   69) <li>Create a presentation that can be used for various user group meetings around the world</li>
en/volunteer.wml   70) <li>Create a video about your positive uses of Tor.  Some have already started on Seesmic.</li>
en/volunteer.wml   71) <li>Create a poster, or a set of posters, around a theme, such as "Tor for Freedom!"</li>
en/volunteer.wml   72) </ol>
en/volunteer.wml   73) 

en/volunteer.wml   74) <a id="Documentation"></a>
en/volunteer.wml   75) <h2><a class="anchor" href="#Documentation">Documentation</a></h2>

volunteer.html     76) <ol>

en/volunteer.wml   77) <li>Please help Matt Edman with the documentation and how-tos for his

en/volunteer.wml   78) Tor controller,
en/volunteer.wml   79) <a href="http://vidalia-project.net/">Vidalia</a>.</li>

en/volunteer.wml   80) <li>Evaluate and document

en/volunteer.wml   81) <a href="https://wiki.torproject.org/wiki/TheOnionRouter/TorifyHOWTO">our

en/volunteer.wml   82) list of programs</a> that can be configured to use Tor.</li>

volunteer.html     83) <li>We need better documentation for dynamically intercepting

en/volunteer.wml   84) connections and sending them through Tor. tsocks (Linux), dsocks (BSD),

en/volunteer.wml   85) and freecap (Windows) seem to be good candidates, as would better
en/volunteer.wml   86) use of our new TransPort feature.</li>

en/volunteer.wml   87) <li>We have a huge list of <a href="https://wiki.torproject.org/noreply/TheOnionRouter/SupportPrograms">potentially useful

volunteer.html     88) programs that interface to Tor</a>. Which ones are useful in which
volunteer.html     89) situations? Please help us test them out and document your results.</li>

en/volunteer.wml   90) <li>Help translate the web page and documentation into other
en/volunteer.wml   91) languages. See the <a href="<page translation>">translation

en/volunteer.wml   92) guidelines</a> if you want to help out. We especially need Arabic or
en/volunteer.wml   93) Farsi translations, for the many Tor users in censored areas.</li>

volunteer.html     94) </ol>
volunteer.html     95) 

en/volunteer.wml   96) <a id="Coding"></a>

en/volunteer.wml   97) <a id="Summer"></a>
en/volunteer.wml   98) <a id="Projects"></a>

en/volunteer.wml   99) <h2><a class="anchor" href="#Projects">Good Coding Projects</a></h2>

en/volunteer.wml  100) 
en/volunteer.wml  101) <p>

en/volunteer.wml  102) You may find some of these projects to be good <a href="<page
en/volunteer.wml  103) gsoc>">Google Summer of Code 2009</a> ideas. We have labelled each idea
en/volunteer.wml  104) with how useful it would be to the overall Tor project (priority), how
en/volunteer.wml  105) much work we expect it would be (effort level), how much clue you should
en/volunteer.wml  106) start with (skill level), and which of our <a href="<page
en/volunteer.wml  107) people>#Core">core developers</a> would be good mentors.
en/volunteer.wml  108) If one or more of these ideas looks promising to you, please <a
en/volunteer.wml  109) href="<page contact>">contact us</a> to discuss your plans rather than
en/volunteer.wml  110) sending blind applications. You may also want to propose your own project
en/volunteer.wml  111) idea which often results in the best applications.

en/volunteer.wml  112) </p>
en/volunteer.wml  113) 

en/volunteer.wml  114) <ol>
en/volunteer.wml  115) 

en/volunteer.wml  116) <li>

en/volunteer.wml  117) <b>Tor Browser Bundle for Linux/Mac OS X</b>

en/volunteer.wml  118) <br />

en/volunteer.wml  119) Priority: <i>High</i>

en/volunteer.wml  120) <br />

en/volunteer.wml  121) Effort Level: <i>High</i>
en/volunteer.wml  122) <br />
en/volunteer.wml  123) Skill Level: <i>Medium</i>
en/volunteer.wml  124) <br />
en/volunteer.wml  125) Likely Mentors: <i>Steven, Andrew</i>
en/volunteer.wml  126) <br />
en/volunteer.wml  127) The Tor Browser bundle incorporates Tor, Firefox, and the Vidalia user
en/volunteer.wml  128) interface (and optionally Pidgin IM). Components are pre-configured to
en/volunteer.wml  129) operate in a secure way, and it has very few dependencies on the
en/volunteer.wml  130) installed operating system. It has therefore become one of the most
en/volunteer.wml  131) easy to use, and popular, ways to use Tor on Windows.
en/volunteer.wml  132) <br />
en/volunteer.wml  133) However, there is currently no comparable package for Linux and Mac OS
en/volunteer.wml  134) X, so this project would be to implement Tor Browser Bundle for these
en/volunteer.wml  135) platforms. This will involve modifications to Vidalia (C++), possibly
en/volunteer.wml  136) Firefox (C) then creating and testing the launcher on a range of
en/volunteer.wml  137) operating system versions and configurations to verify portability.
en/volunteer.wml  138) <br />
en/volunteer.wml  139) Students should be familiar with application development on one or
en/volunteer.wml  140) preferably both of Linux and Mac OS X, and be comfortable with C/C++
en/volunteer.wml  141) and shell scripting.
en/volunteer.wml  142) <br />
en/volunteer.wml  143) Part of this project could be usability testing of Tor Browser Bundle,
en/volunteer.wml  144) ideally amongst our target demographic.
en/volunteer.wml  145) That would help a lot in knowing what needs to be done in terms of bug
en/volunteer.wml  146) fixes or new features. We get this informally at the moment, but a more
en/volunteer.wml  147) structured process would be better.
en/volunteer.wml  148) </li>
en/volunteer.wml  149) 
en/volunteer.wml  150) <li>
en/volunteer.wml  151) <b>Translation wiki for our website</b>
en/volunteer.wml  152) <br />
en/volunteer.wml  153) Priority: <i>High</i>
en/volunteer.wml  154) <br />
en/volunteer.wml  155) Effort Level: <i>Medium</i>
en/volunteer.wml  156) <br />
en/volunteer.wml  157) Skill Level: <i>Medium</i>
en/volunteer.wml  158) <br />
en/volunteer.wml  159) Likely Mentors: <i>Jacob</i>
en/volunteer.wml  160) <br />
en/volunteer.wml  161) The Tor Project has been working over the past year to set up web-based
en/volunteer.wml  162) tools to help volunteers translate our applications into other languages.
en/volunteer.wml  163) We finally hit upon Pootle, and we have a fine web-based translation engine
en/volunteer.wml  164) in place for Vidalia, Torbutton, and Torcheck. However, Pootle only
en/volunteer.wml  165) translates strings that are in the "po" format, and our website uses wml
en/volunteer.wml  166) files. This project is about finding a way to convert our wml files into po
en/volunteer.wml  167) strings and back, so they can be handled by Pootle.

en/volunteer.wml  168) </li>
en/volunteer.wml  169) 
en/volunteer.wml  170) <li>
en/volunteer.wml  171) <b>Help track the overall Tor Network status</b>

en/volunteer.wml  172) <br />

en/volunteer.wml  173) Priority: <i>Medium to High</i>
en/volunteer.wml  174) <br />
en/volunteer.wml  175) Effort Level: <i>Medium</i>
en/volunteer.wml  176) <br />
en/volunteer.wml  177) Skill Level: <i>Medium</i>
en/volunteer.wml  178) <br />

en/volunteer.wml  179) Likely Mentors: <i>Karsten, Roger</i>

en/volunteer.wml  180) <br />

en/volunteer.wml  181) It would be great to set up an automated system for tracking network
en/volunteer.wml  182) health over time, graphing it, etc. Part of this project would involve
en/volunteer.wml  183) inventing better metrics for assessing network health and growth. Is the
en/volunteer.wml  184) average uptime of the network increasing? How many relays are qualifying
en/volunteer.wml  185) for Guard status this month compared to last month? What's the turnover
en/volunteer.wml  186) in terms of new relays showing up and relays shutting off? Periodically
en/volunteer.wml  187) people collect brief snapshots, but where it gets really interesting is
en/volunteer.wml  188) when we start tracking data points over time.
en/volunteer.wml  189) <br />

en/volunteer.wml  190) Data could be collected from the Tor Network Scanners in <a
en/volunteer.wml  191) href="https://svn.torproject.org/svn/torflow/trunk/README">TorFlow</a>, from

en/volunteer.wml  192) the server descriptors that each relay publishes, and from other
en/volunteer.wml  193) sources. Results over time could be integrated into one of the <a
en/volunteer.wml  194) href="https://torstatus.blutmagie.de/">Tor Status</a> web pages, or be
en/volunteer.wml  195) kept separate. Speaking of the Tor Status pages, take a look at Roger's
en/volunteer.wml  196) <a href="http://archives.seul.org/or/talk/Jan-2008/msg00300.html">Tor
en/volunteer.wml  197) Status wish list</a>.
en/volunteer.wml  198) </li>
en/volunteer.wml  199) 
en/volunteer.wml  200) <li>
en/volunteer.wml  201) <b>Improving Tor's ability to resist censorship</b>
en/volunteer.wml  202) <br />

en/volunteer.wml  203) Priority: <i>Medium to High</i>

en/volunteer.wml  204) <br />

en/volunteer.wml  205) Effort Level: <i>Medium</i>

en/volunteer.wml  206) <br />
en/volunteer.wml  207) Skill Level: <i>High</i>
en/volunteer.wml  208) <br />

en/volunteer.wml  209) Likely Mentors: <i>Nick, Roger, Steven</i>

en/volunteer.wml  210) <br />

en/volunteer.wml  211) The Tor 0.2.0.x series makes <a
en/volunteer.wml  212) href="<svnsandbox>doc/design-paper/blocking.html">significant
en/volunteer.wml  213) improvements</a> in resisting national and organizational censorship.
en/volunteer.wml  214) But Tor still needs better mechanisms for some parts of its
en/volunteer.wml  215) anti-censorship design.  For example, current Tors can only listen on a
en/volunteer.wml  216) single address/port combination at a time.  There's
en/volunteer.wml  217) <a href="<svnsandbox>doc/spec/proposals/118-multiple-orports.txt">a
en/volunteer.wml  218) proposal to address this limitation</a> and allow clients to connect
en/volunteer.wml  219) to any given Tor on multiple addresses and ports, but it needs more
en/volunteer.wml  220) work.  Another anti-censorship project (far more difficult) is to try
en/volunteer.wml  221) to make Tor more scanning-resistant.  Right now, an adversary can identify
en/volunteer.wml  222) <a href="<svnsandbox>doc/spec/proposals/125-bridges.txt">Tor bridges</a>
en/volunteer.wml  223) just by trying to connect to them, following the Tor protocol, and
en/volunteer.wml  224) seeing if they respond.  To solve this, bridges could
en/volunteer.wml  225) <a href="<svnsandbox>doc/design-paper/blocking.html#tth_sEc9.3">act like
en/volunteer.wml  226) webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
en/volunteer.wml  227) and not act like bridges until the user provides a bridge-specific key.
en/volunteer.wml  228) <br />
en/volunteer.wml  229) This project involves a lot of research and design. One of the big
en/volunteer.wml  230) challenges will be identifying and crafting approaches that can still
en/volunteer.wml  231) resist an adversary even after the adversary knows the design, and
en/volunteer.wml  232) then trading off censorship resistance with usability and robustness.
en/volunteer.wml  233) </li>
en/volunteer.wml  234) 
en/volunteer.wml  235) <li>

en/volunteer.wml  236) <b>Tuneup Tor!</b>

en/volunteer.wml  237) <br />

en/volunteer.wml  238) Priority: <i>Medium to High</i>

en/volunteer.wml  239) <br />

en/volunteer.wml  240) Effort Level: <i>Medium to High</i>

en/volunteer.wml  241) <br />

en/volunteer.wml  242) Skill Level: <i>High</i>
en/volunteer.wml  243) <br />
en/volunteer.wml  244) Likely Mentors: <i>Nick, Roger, Mike, Karsten</i>
en/volunteer.wml  245) <br />
en/volunteer.wml  246) Right now, Tor relays measure and report their own bandwidth, and Tor
en/volunteer.wml  247) clients choose which relays to use in part based on that bandwidth.
en/volunteer.wml  248) This approach is vulnerable to
en/volunteer.wml  249) <a href="http://freehaven.net/anonbib/#bauer:wpes2007">attacks where
en/volunteer.wml  250) relays lie about their bandwidth</a>;
en/volunteer.wml  251) to address this, Tor currently caps the maximum bandwidth
en/volunteer.wml  252) it's willing to believe any relay provides.  This is a limited fix, and
en/volunteer.wml  253) a waste of bandwidth capacity to boot.  Instead,
en/volunteer.wml  254) Tor should possibly measure bandwidth in a more distributed way, perhaps
en/volunteer.wml  255) as described in the
en/volunteer.wml  256) <a href="http://freehaven.net/anonbib/author.html#snader08">"A Tune-up for
en/volunteer.wml  257) Tor"</a> paper
en/volunteer.wml  258) by Snader and Borisov. One could use current testing code to
en/volunteer.wml  259) double-check this paper's findings and verify the extent to which they
en/volunteer.wml  260) dovetail with Tor as deployed in the wild, and determine good ways to
en/volunteer.wml  261) incorporate them into their suggestions Tor network without adding too
en/volunteer.wml  262) much communications overhead between relays and directory
en/volunteer.wml  263) authorities.

en/volunteer.wml  264) </li>
en/volunteer.wml  265) 
en/volunteer.wml  266) <li>

en/volunteer.wml  267) <b>Improving Polipo on Windows</b>

en/volunteer.wml  268) <br />

en/volunteer.wml  269) Priority: <i>Medium to High</i>

en/volunteer.wml  270) <br />
en/volunteer.wml  271) Effort Level: <i>Medium</i>
en/volunteer.wml  272) <br />
en/volunteer.wml  273) Skill Level: <i>Medium</i>
en/volunteer.wml  274) <br />

en/volunteer.wml  275) Likely Mentors: <i>Martin</i>

en/volunteer.wml  276) <br />

en/volunteer.wml  277) Help port <a
en/volunteer.wml  278) href="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</a> to
en/volunteer.wml  279) Windows. Example topics to tackle include:
en/volunteer.wml  280) 1) the ability to asynchronously
en/volunteer.wml  281) query name servers, find the system nameservers, and manage netbios
en/volunteer.wml  282) and dns queries.
en/volunteer.wml  283) 2) manage events and buffers
en/volunteer.wml  284) natively (i.e. in Unix-like OSes, Polipo defaults to 25% of ram, in
en/volunteer.wml  285) Windows it's whatever the config specifies). 3) some sort of GUI config
en/volunteer.wml  286) and reporting tool, bonus if it has a systray icon with right clickable
en/volunteer.wml  287) menu options. Double bonus if it's cross-platform compatible.

en/volunteer.wml  288) 4) allow the software to use the Windows Registry and handle proper
en/volunteer.wml  289) Windows directory locations, such as "C:\Program Files\Polipo"

en/volunteer.wml  290) </li>
en/volunteer.wml  291) 
en/volunteer.wml  292) <li>
en/volunteer.wml  293) <b>Implement a torrent-based scheme for downloading Thandy packages</b>

en/volunteer.wml  294) <br />

en/volunteer.wml  295) Priority: <i>Medium to High</i>

en/volunteer.wml  296) <br />

en/volunteer.wml  297) Effort Level: <i>High</i>
en/volunteer.wml  298) <br />
en/volunteer.wml  299) Skill Level: <i>Medium to High</i>
en/volunteer.wml  300) <br />
en/volunteer.wml  301) Likely Mentors: <i>Martin, Nick</i>
en/volunteer.wml  302) <br />
en/volunteer.wml  303) <a
en/volunteer.wml  304) href="http://git.torproject.org/checkout/thandy/master/specs/thandy-spec.txt">Thandy</a>
en/volunteer.wml  305) is a relatively new software to allow assisted updates of Tor and related
en/volunteer.wml  306) software. Currently, there are very few users, but we expect Thandy to be
en/volunteer.wml  307) used by almost every Tor user in the future. To avoid crashing servers on
en/volunteer.wml  308) the day of a Tor update, we need new ways to distribute new packages
en/volunteer.wml  309) efficiently, and using libtorrent seems to be a possible solution. If you
en/volunteer.wml  310) think of other good ideas, great - please do let us know!<br />
en/volunteer.wml  311) We also need to investigate how to include our mirrors better. If possible,
en/volunteer.wml  312) there should be an easy way for them to help distributing the packages.

en/volunteer.wml  313) </li>
en/volunteer.wml  314) 

en/volunteer.wml  315) <li>

en/volunteer.wml  316) <b>Tor Controller Status Event Interface</b>

en/volunteer.wml  317) <br />

en/volunteer.wml  318) Priority: <i>Medium</i>
en/volunteer.wml  319) <br />
en/volunteer.wml  320) Effort Level: <i>Medium</i>
en/volunteer.wml  321) <br />

en/volunteer.wml  322) Skill Level: <i>Low to Medium</i>

en/volunteer.wml  323) <br />
en/volunteer.wml  324) Likely Mentors: <i>Matt</i>
en/volunteer.wml  325) <br />

en/volunteer.wml  326) There are a number of status changes inside Tor of which the user may need

en/volunteer.wml  327) to be informed. For example, if the user is trying to set up his Tor as a
en/volunteer.wml  328) relay and Tor decides that its ports are not reachable from outside

en/volunteer.wml  329) the user's network, we should alert the user. Currently, all the user

en/volunteer.wml  330) gets is a couple log messages in Vidalia's 'message log' window, which they

en/volunteer.wml  331) likely never see since they don't receive a notification that something
en/volunteer.wml  332) has gone wrong. Even if the user does actually look at the message log,
en/volunteer.wml  333) most of the messages make little sense to the novice user.
en/volunteer.wml  334) <br />
en/volunteer.wml  335) Tor has the ability to inform Vidalia of many such status changes, and
en/volunteer.wml  336) we recently implemented support for a couple of these events. Still,
en/volunteer.wml  337) there are many more status events the user should be informed of and we
en/volunteer.wml  338) need a better UI for actually displaying them to the user.
en/volunteer.wml  339) <br />
en/volunteer.wml  340) The goal of this project then is to design and implement a UI for
en/volunteer.wml  341) displaying Tor status events to the user. For example, we might put a
en/volunteer.wml  342) little badge on Vidalia's tray icon that alerts the user to new status
en/volunteer.wml  343) events they should look at. Double-clicking the icon could bring up a
en/volunteer.wml  344) dialog that summarizes recent status events in simple terms and maybe

en/volunteer.wml  345) suggests a remedy for any negative events if they can be corrected by

en/volunteer.wml  346) the user. Of course, this is just an example and one is free to

en/volunteer.wml  347) suggest another approach.
en/volunteer.wml  348) <br />

en/volunteer.wml  349) A person undertaking this project should have good UI design and layout

en/volunteer.wml  350) and some C++ development experience. Previous experience with Qt and

en/volunteer.wml  351) Qt's Designer will be very helpful, but are not required. Some

en/volunteer.wml  352) English writing ability will also be useful, since this project will
en/volunteer.wml  353) likely involve writing small amounts of help documentation that should
en/volunteer.wml  354) be understandable by non-technical users. Bonus points for some graphic
en/volunteer.wml  355) design/Photoshop fu, since we might want/need some shiny new icons too.
en/volunteer.wml  356) </li>
en/volunteer.wml  357) 

en/volunteer.wml  358) <li>

en/volunteer.wml  359) <b>Improve our unit testing process</b>

en/volunteer.wml  360) <br />

en/volunteer.wml  361) Priority: <i>Medium</i>

en/volunteer.wml  362) <br />

en/volunteer.wml  363) Effort Level: <i>Medium</i>
en/volunteer.wml  364) <br />
en/volunteer.wml  365) Skill Level: <i>Medium</i>
en/volunteer.wml  366) <br />
en/volunteer.wml  367) Likely Mentors: <i>Nick, Roger</i>
en/volunteer.wml  368) <br />
en/volunteer.wml  369) Tor needs to be far more tested. This is a multi-part effort. To start
en/volunteer.wml  370) with, our unit test coverage should rise substantially, especially in
en/volunteer.wml  371) the areas outside the utility functions. This will require significant
en/volunteer.wml  372) refactoring of some parts of Tor, in order to dissociate as much logic
en/volunteer.wml  373) as possible from globals.
en/volunteer.wml  374) <br />
en/volunteer.wml  375) Additionally, we need to automate our performance testing. We've got
en/volunteer.wml  376) buildbot to automate our regular integration and compile testing already
en/volunteer.wml  377) (though we need somebody to set it up on Windows),
en/volunteer.wml  378) but we need to get our network simulation tests (as built in <a
en/volunteer.wml  379) href="https://svn.torproject.org/svn/torflow/trunk/README">TorFlow</a>)
en/volunteer.wml  380) updated for more recent versions of Tor, and designed to launch a test
en/volunteer.wml  381) network either on a single machine, or across several, so we can test
en/volunteer.wml  382) changes in performance on machines in different roles automatically.
en/volunteer.wml  383) </li>
en/volunteer.wml  384) 
en/volunteer.wml  385) <li>
en/volunteer.wml  386) <b>Help revive an independent Tor client implementation</b>
en/volunteer.wml  387) <br />
en/volunteer.wml  388) Priority: <i>Medium</i>
en/volunteer.wml  389) <br />
en/volunteer.wml  390) Effort Level: <i>High</i>
en/volunteer.wml  391) <br />
en/volunteer.wml  392) Skill Level: <i>Medium to High</i>
en/volunteer.wml  393) <br />
en/volunteer.wml  394) Likely Mentors: <i>Karsten, Nick</i>
en/volunteer.wml  395) <br />
en/volunteer.wml  396) Reanimate one of the approaches to implement a Tor client in Java,
en/volunteer.wml  397) e.g. the <a href="http://onioncoffee.sourceforge.net/">OnionCoffee
en/volunteer.wml  398) project</a>, and make it run on <a
en/volunteer.wml  399) href="http://code.google.com/android/">Android</a>. The first step
en/volunteer.wml  400) would be to port the existing code and execute it in an Android
en/volunteer.wml  401) environment. Next, the code should be updated to support the newer Tor
en/volunteer.wml  402) protocol versions like the <a href="<svnsandbox>doc/spec/dir-spec.txt">v3
en/volunteer.wml  403) directory protocol</a>. Further, support for requesting or even
en/volunteer.wml  404) providing Tor hidden services would be neat, but not required.
en/volunteer.wml  405) <br />
en/volunteer.wml  406) A prospective developer should be able to understand and write new Java
en/volunteer.wml  407) code, including
en/volunteer.wml  408) a Java cryptography API. Being able to read C code would be helpful,
en/volunteer.wml  409) too. One should be willing to read the existing documentation,
en/volunteer.wml  410) implement code based on it, and refine the documentation
en/volunteer.wml  411) when things are underdocumented. This project is mostly about coding and
en/volunteer.wml  412) to a small degree about design.
en/volunteer.wml  413) </li>
en/volunteer.wml  414) 
en/volunteer.wml  415) <li>
en/volunteer.wml  416) <b>New Torbutton Features</b>
en/volunteer.wml  417) <br />
en/volunteer.wml  418) Priority: <i>Medium</i>
en/volunteer.wml  419) <br />
en/volunteer.wml  420) Effort Level: <i>High</i>
en/volunteer.wml  421) <br />
en/volunteer.wml  422) Skill Level: <i>High</i>
en/volunteer.wml  423) <br />
en/volunteer.wml  424) Likely Mentors: <i>Mike</i>
en/volunteer.wml  425) <br/>
en/volunteer.wml  426) There are several <a
en/volunteer.wml  427) href="https://bugs.torproject.org/flyspray/index.php?tasks=all&amp;project=5&amp;type=2">good
en/volunteer.wml  428) feature requests</a> on the Torbutton Flyspray section. In particular, <a
en/volunteer.wml  429) href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=523">Integrating
en/volunteer.wml  430) 'New Identity' with Vidalia</a>,
en/volunteer.wml  431) <a href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=940">ways of
en/volunteer.wml  432) managing multiple cookie jars/identities</a>, <a
en/volunteer.wml  433) href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=637">preserving
en/volunteer.wml  434) specific cookies</a> when cookies are cleared,
en/volunteer.wml  435) <a
en/volunteer.wml  436) href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=524">better
en/volunteer.wml  437) referrer spoofing</a>, <a
en/volunteer.wml  438) href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=564">correct
en/volunteer.wml  439) Tor status reporting</a>, and <a
en/volunteer.wml  440) href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=462">"tor://"
en/volunteer.wml  441) and "tors://" urls</a> are all interesting
en/volunteer.wml  442) features that could be added.
en/volunteer.wml  443) <br />
en/volunteer.wml  444) This work would be independent coding in Javascript and the fun world of <a
en/volunteer.wml  445) href="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">XUL</a>,
en/volunteer.wml  446) with not too much involvement in the Tor internals.
en/volunteer.wml  447) </li>
en/volunteer.wml  448) 
en/volunteer.wml  449) <li>
en/volunteer.wml  450) <b>New Thandy Features</b>
en/volunteer.wml  451) <br />
en/volunteer.wml  452) Priority: <i>Medium</i>
en/volunteer.wml  453) <br />
en/volunteer.wml  454) Effort Level: <i>Medium</i>
en/volunteer.wml  455) <br />
en/volunteer.wml  456) Skill Level: <i>Medium to High</i>
en/volunteer.wml  457) <br />
en/volunteer.wml  458) Likely Mentors: <i>Martin</i>
en/volunteer.wml  459) <br />
en/volunteer.wml  460) Additional capabilities are needed for assisted updates of all the Tor
en/volunteer.wml  461) related software for Windows and other operating systems. Some of the
en/volunteer.wml  462) features to consider include:
en/volunteer.wml  463) 1) Integration of the <a
en/volunteer.wml  464) href="http://chandlerproject.org/Projects/MeTooCrypto">MeTooCrypto
en/volunteer.wml  465) Python library</a>
en/volunteer.wml  466) for authenticated HTTPS downloads. 2) Adding a level of indirection
en/volunteer.wml  467) between the timestamp signatures and the package files included in an
en/volunteer.wml  468) update. See the "Thandy attacks / suggestions" thread on or-dev.
en/volunteer.wml  469) 3) Support locale specific installation and configuration of assisted
en/volunteer.wml  470) updates based on preference, host, or user account language settings.
en/volunteer.wml  471) Familiarity with Windows codepages, unicode, and other character sets
en/volunteer.wml  472) is helpful in addition to general win32 and posix API experience and
en/volunteer.wml  473) Python proficiency.
en/volunteer.wml  474) </li>
en/volunteer.wml  475) 
en/volunteer.wml  476) <li>
en/volunteer.wml  477) <b>Simulator for slow Internet connections</b>
en/volunteer.wml  478) <br />
en/volunteer.wml  479) Priority: <i>Medium</i>
en/volunteer.wml  480) <br />
en/volunteer.wml  481) Effort Level: <i>Medium</i>
en/volunteer.wml  482) <br />
en/volunteer.wml  483) Skill Level: <i>Medium</i>
en/volunteer.wml  484) <br />
en/volunteer.wml  485) Likely Mentors: <i>Steven</i>
en/volunteer.wml  486) <br />
en/volunteer.wml  487) Many users of Tor have poor-quality Internet connections, giving low
en/volunteer.wml  488) bandwidth, high latency, and high packet loss/re-ordering. User
en/volunteer.wml  489) experience is that Tor reacts badly to these conditions, but it is
en/volunteer.wml  490) difficult to improve the situation without being able to repeat the
en/volunteer.wml  491) problems in the lab.
en/volunteer.wml  492) <br />
en/volunteer.wml  493) This project would be to build a simulation environment which
en/volunteer.wml  494) replicates the poor connectivity so that the effect on Tor performance
en/volunteer.wml  495) can be measured. Other components would be a testing utility to
en/volunteer.wml  496) establish what are the properties of connections available, and to
en/volunteer.wml  497) measure the effect of performance-improving modifications to Tor.
en/volunteer.wml  498) <br />
en/volunteer.wml  499) The tools used would be up to the student, but dummynet (for FreeBSD)
en/volunteer.wml  500) and nistnet (for Linux) are two potential components on which this
en/volunteer.wml  501) project could be built. Students should be experienced with network
en/volunteer.wml  502) programming/debugging and TCP/IP, and preferably familiar with C and a
en/volunteer.wml  503) scripting language.
en/volunteer.wml  504) </li>
en/volunteer.wml  505) 
en/volunteer.wml  506) <li>
en/volunteer.wml  507) <b>An Improved and More Usable Network Map in Vidalia</b>
en/volunteer.wml  508) <br />
en/volunteer.wml  509) Priority: <i>Low to Medium</i>
en/volunteer.wml  510) <br />
en/volunteer.wml  511) Effort Level: <i>Medium</i>
en/volunteer.wml  512) <br />
en/volunteer.wml  513) Skill Level: <i>Medium</i>
en/volunteer.wml  514) <br />
en/volunteer.wml  515) Likely Mentors: <i>Matt</i>
en/volunteer.wml  516) <br />
en/volunteer.wml  517) One of Vidalia's existing features is a network map that shows the user
en/volunteer.wml  518) the approximate geographic location of relays in the Tor network and
en/volunteer.wml  519) plots the paths the user's traffic takes as it is tunneled through the
en/volunteer.wml  520) Tor network. The map is currently not very interactive and has rather
en/volunteer.wml  521) poor graphics. Instead, we implemented KDE's Marble widget such
en/volunteer.wml  522) that it gives us a better quality map and enables improved interactivity,
en/volunteer.wml  523) such as allowing the user to click on individual relays or circuits to
en/volunteer.wml  524) display additional information. We want to add the ability
en/volunteer.wml  525) for users to click on a particular relay or a country containing one or
en/volunteer.wml  526) more Tor exit relays and say, "I want my connections to exit
en/volunteer.wml  527) from here."
en/volunteer.wml  528) <br />
en/volunteer.wml  529) This project will first involve getting familiar with Vidalia
en/volunteer.wml  530) and the Marble widget's API. One will then integrate the widget
en/volunteer.wml  531) into Vidalia and customize Marble to be better suited for our application,
en/volunteer.wml  532) such as making circuits clickable, storing cached map data in Vidalia's
en/volunteer.wml  533) own data directory, and customizing some of the widget's dialogs.
en/volunteer.wml  534) <br />
en/volunteer.wml  535) A person undertaking this project should have good C++ development
en/volunteer.wml  536) experience. Previous experience with Qt and CMake is helpful, but not
en/volunteer.wml  537) required.
en/volunteer.wml  538) </li>
en/volunteer.wml  539) 
en/volunteer.wml  540) <li>
en/volunteer.wml  541) <b>Bring moniTor to life</b>
en/volunteer.wml  542) <br />
en/volunteer.wml  543) Priority: <i>Low</i>
en/volunteer.wml  544) <br />
en/volunteer.wml  545) Effort Level: <i>Medium</i>
en/volunteer.wml  546) <br />
en/volunteer.wml  547) Skill Level: <i>Low to Medium</i>
en/volunteer.wml  548) <br />
en/volunteer.wml  549) Likely Mentors: <i>Karsten, Jacob</i>
en/volunteer.wml  550) <br />
en/volunteer.wml  551) Implement a <a href="http://www.ss64.com/bash/top.html">top-like</a>
en/volunteer.wml  552) management tool for Tor relays. The purpose of such a tool would be
en/volunteer.wml  553) to monitor a local Tor relay via its control port and include useful
en/volunteer.wml  554) system information of the underlying machine. When running this tool, it
en/volunteer.wml  555) would dynamically update its content like top does for Linux processes.
en/volunteer.wml  556) <a href="http://archives.seul.org/or/dev/Jan-2008/msg00005.html">This
en/volunteer.wml  557) or-dev post</a> might be a good first read.
en/volunteer.wml  558) <br />
en/volunteer.wml  559) A person interested in this should be familiar
en/volunteer.wml  560) with or willing to learn about administering a Tor relay and configuring
en/volunteer.wml  561) it via its control port. As an initial prototype is written in Python,
en/volunteer.wml  562) some knowledge about writing Python code would be helpful, too. This
en/volunteer.wml  563) project is one part about identifying requirements to such a
en/volunteer.wml  564) tool and designing its interface, and one part lots of coding.
en/volunteer.wml  565) </li>
en/volunteer.wml  566) 
en/volunteer.wml  567) <li>
en/volunteer.wml  568) <b>Torbutton equivalent for Thunderbird</b>
en/volunteer.wml  569) <br />
en/volunteer.wml  570) Priority: <i>Low</i>
en/volunteer.wml  571) <br />
en/volunteer.wml  572) Effort Level: <i>High</i>
en/volunteer.wml  573) <br />
en/volunteer.wml  574) Skill Level: <i>High</i>
en/volunteer.wml  575) <br />
en/volunteer.wml  576) Likely Mentors: <i>Mike</i>
en/volunteer.wml  577) <br />
en/volunteer.wml  578) We're hearing from an increasing number of users that they want to use
en/volunteer.wml  579) Thunderbird with Tor. However, there are plenty of application-level
en/volunteer.wml  580) concerns, for example, by default Thunderbird will put your hostname in
en/volunteer.wml  581) the outgoing mail that it sends. At some point we should start a new
en/volunteer.wml  582) push to build a Thunderbird extension similar to Torbutton.
en/volunteer.wml  583) </li>
en/volunteer.wml  584) 
en/volunteer.wml  585) <li>
en/volunteer.wml  586) <b>Intermediate Level Network Device Driver</b>
en/volunteer.wml  587) <br />
en/volunteer.wml  588) Priority: <i>Low</i>
en/volunteer.wml  589) <br />
en/volunteer.wml  590) Effort Level: <i>High</i>
en/volunteer.wml  591) <br />
en/volunteer.wml  592) Skill Level: <i>High</i>
en/volunteer.wml  593) <br />
en/volunteer.wml  594) Likely Mentors: <i>Martin</i>
en/volunteer.wml  595) <br />
en/volunteer.wml  596) The WinPCAP device driver used by Tor VM for bridged networking does
en/volunteer.wml  597) not support a number of wireless and non-Ethernet network adapters.
en/volunteer.wml  598) Implementation of a intermediate level network device driver for win32
en/volunteer.wml  599) and 64bit would provide a way to intercept and route traffic over such
en/volunteer.wml  600) networks. This project will require knowledge of and experience with
en/volunteer.wml  601) Windows kernel device driver development and testing. Familiarity with
en/volunteer.wml  602) Winsock and Qemu would also be helpful.
en/volunteer.wml  603) </li>
en/volunteer.wml  604) 

en/volunteer.wml  605) <li>
en/volunteer.wml  606) <b>Improve Tor Weather</b>
en/volunteer.wml  607) <br />
en/volunteer.wml  608) Priority: <i>Medium</i>
en/volunteer.wml  609) <br />
en/volunteer.wml  610) Effort Level: <i>Medium</i>
en/volunteer.wml  611) <br />
en/volunteer.wml  612) Skill Level: <i>Medium</i>
en/volunteer.wml  613) <br />

en/volunteer.wml  614) Likely Mentors: <i>Jake, Roger</i>

en/volunteer.wml  615) <br />
en/volunteer.wml  616) <a href="https://weather.torproject.org/">Tor weather</a> is a tool
en/volunteer.wml  617) that allows signing up to receive notifications via email when the
en/volunteer.wml  618) tracked Tor relay is down. Currently, it isn't really useful for
en/volunteer.wml  619) people who use the hibernation feature of Tor, or for those who
en/volunteer.wml  620) have to shut down their relay regularly. During the project, Tor

en/volunteer.wml  621) weather could be extended to allow more flexible configurations.

en/volunteer.wml  622) Other enhancements are also possible: Weather could send out warnings

en/volunteer.wml  623) when your relay runs an out-of-date version of Tor, or when its

en/volunteer.wml  624) observed bandwith drops below a certain value. It might also be a
en/volunteer.wml  625) nice tool that allows for checking whether your relay has earned

en/volunteer.wml  626) you a <a href="<page tshirt>">T-Shirt</a>, or sending reminders to
en/volunteer.wml  627) directory authorities that
en/volunteer.wml  628) their keys are about to expire. Be creative, and consider how the
en/volunteer.wml  629) above project to track overall network status can help you get your job
en/volunteer.wml  630) done more quickly! See also its
en/volunteer.wml  631) <a href="https://svn.torproject.org/svn/weather/trunk/README">README</a>
en/volunteer.wml  632) and <a href="https://svn.torproject.org/svn/weather/trunk/TODO">TODO</a>.

en/volunteer.wml  633) </li>
en/volunteer.wml  634) 

en/volunteer.wml  635) <li>
en/volunteer.wml  636) <b>Bring up new ideas!</b>
en/volunteer.wml  637) <br />
en/volunteer.wml  638) Don't like any of these? Look at the <a
en/volunteer.wml  639) href="<svnsandbox>doc/roadmaps/2008-12-19-roadmap-full.pdf">Tor development
en/volunteer.wml  640) roadmap</a> for more ideas.
en/volunteer.wml  641) Some of the <a href="<svnsandbox>doc/spec/proposals/">current proposals</a>
en/volunteer.wml  642) might also be short on developers.
en/volunteer.wml  643) </li>
en/volunteer.wml  644) 
en/volunteer.wml  645) <!-- Mike is already working on this.
en/volunteer.wml  646) <li>
en/volunteer.wml  647) <b>Tor Node Scanner improvements</b>
en/volunteer.wml  648) <br />
en/volunteer.wml  649) Similar to the SoaT exit scanner (or perhaps even during exit scanning),
en/volunteer.wml  650) statistics can be gathered about the reliability of nodes. Nodes that
en/volunteer.wml  651) fail too high a percentage of their circuits should not be given
en/volunteer.wml  652) Guard status. Perhaps they should have their reported bandwidth
en/volunteer.wml  653) penalized by some ratio as well, or just get marked as Invalid. In
en/volunteer.wml  654) addition, nodes that exhibit a very low average stream capacity but
en/volunteer.wml  655) advertise a very high node bandwidth can also be marked as Invalid.
en/volunteer.wml  656) Much of this statistics gathering is already done, it just needs to be
en/volunteer.wml  657) transformed into something that can be reported to the Directory
en/volunteer.wml  658) Authorities to blacklist/penalize nodes in such a way that clients
en/volunteer.wml  659) will listen.
en/volunteer.wml  660) <br />
en/volunteer.wml  661) In addition, these same statistics can be gathered about the traffic
en/volunteer.wml  662) through a node. Events can be added to the <a
en/volunteer.wml  663) href="https://svn.torproject.org/svn/torctl/trunk/doc/howto.txt">Tor Control
en/volunteer.wml  664) Protocol</a> to
en/volunteer.wml  665) report if a circuit extend attempt through the node succeeds or fails, and
en/volunteer.wml  666) passive statistics can be gathered on both bandwidth and reliability
en/volunteer.wml  667) of other nodes via a node-based monitor using these events. Such a
en/volunteer.wml  668) scanner would also report information on oddly-behaving nodes to
en/volunteer.wml  669) the Directory Authorities, but a communication channel for this
en/volunteer.wml  670) currently does not exist and would need to be developed as well.
en/volunteer.wml  671) </li>
en/volunteer.wml  672) -->
en/volunteer.wml  673) 
en/volunteer.wml  674) <!-- Is this still a useful project? If so, move it to another section.
en/volunteer.wml  675) <li>
en/volunteer.wml  676) <b>Better Debian/Ubuntu Packaging for Tor+Vidalia</b>
en/volunteer.wml  677) <br />
en/volunteer.wml  678) Vidalia currently doesn't play nicely on Debian and Ubuntu with the
en/volunteer.wml  679) default Tor packages. The current Tor packages automatically start Tor
en/volunteer.wml  680) as a daemon running as the debian-tor user and (sensibly) do not have a
en/volunteer.wml  681) <a href="<svnsandbox>doc/spec/control-spec.txt">ControlPort</a> defined
en/volunteer.wml  682) in the default torrc. Consequently, Vidalia will try
en/volunteer.wml  683) to start its own Tor process since it could not connect to the existing
en/volunteer.wml  684) Tor, and Vidalia's Tor process will then exit with an error message
en/volunteer.wml  685) the user likely doesn't understand since Tor cannot bind its listening
en/volunteer.wml  686) ports &mdash; they're already in use by the original Tor daemon.
en/volunteer.wml  687) <br />
en/volunteer.wml  688) The current solution involves either telling the user to stop the
en/volunteer.wml  689) existing Tor daemon and let Vidalia start its own Tor process, or
en/volunteer.wml  690) explaining to the user how to set a control port and password in their
en/volunteer.wml  691) torrc. A better solution on Debian would be to use Tor's ControlSocket,
en/volunteer.wml  692) which allows Vidalia to talk to Tor via a Unix domain socket, and could
en/volunteer.wml  693) possibly be enabled by default in Tor's Debian packages. Vidalia can
en/volunteer.wml  694) then authenticate to Tor using filesystem-based (cookie) authentication
en/volunteer.wml  695) if the user running Vidalia is also in the debian-tor group.
en/volunteer.wml  696) <br />
en/volunteer.wml  697) This project will first involve adding support for Tor's ControlSocket
en/volunteer.wml  698) to Vidalia. The student will then develop and test Debian and Ubuntu
en/volunteer.wml  699) packages for Vidalia that conform to Debian's packaging standards and
en/volunteer.wml  700) make sure they work well with the existing Tor packages. We can also
en/volunteer.wml  701) set up an apt repository to host the new Vidalia packages.
en/volunteer.wml  702) <br />
en/volunteer.wml  703) The next challenge would be to find an intuitive usable way for Vidalia
en/volunteer.wml  704) to be able to change Tor's configuration (torrc) even though it is
en/volunteer.wml  705) located in <code>/etc/tor/torrc</code> and thus immutable. The best
en/volunteer.wml  706) idea we've come up with so far is to feed Tor a new configuration via
en/volunteer.wml  707) the ControlSocket when Vidalia starts, but that's bad because Tor starts
en/volunteer.wml  708) each boot with a different configuration than the user wants. The second
en/volunteer.wml  709) best idea
en/volunteer.wml  710) we've come up with is for Vidalia to write out a temporary torrc file
en/volunteer.wml  711) and ask the user to manually move it to <code>/etc/tor/torrc</code>,
en/volunteer.wml  712) but that's bad because users shouldn't have to mess with files directly.
en/volunteer.wml  713) <br />
en/volunteer.wml  714) A person undertaking this project should have prior knowledge of
en/volunteer.wml  715) Debian package management and some C++ development experience. Previous
en/volunteer.wml  716) experience with Qt is helpful, but not required.
en/volunteer.wml  717) </li>
en/volunteer.wml  718) -->
en/volunteer.wml  719) 
en/volunteer.wml  720) <!-- This should be mostly done.
en/volunteer.wml  721) <li>
en/volunteer.wml  722) <b>Tor/Polipo/Vidalia Auto-Update Framework</b>
en/volunteer.wml  723) <br />
en/volunteer.wml  724) We're in need of a good authenticated-update framework.
en/volunteer.wml  725) Vidalia already has the ability to notice when the user is running an
en/volunteer.wml  726) outdated or unrecommended version of Tor, using signed statements inside
en/volunteer.wml  727) the Tor directory information. Currently, Vidalia simply pops
en/volunteer.wml  728) up a little message box that lets the user know they should manually
en/volunteer.wml  729) upgrade. The goal of this project would be to extend Vidalia with the
en/volunteer.wml  730) ability to also fetch and install the updated Tor software for the
en/volunteer.wml  731) user. We should do the fetches via Tor when possible, but also fall back
en/volunteer.wml  732) to direct fetches in a smart way. Time permitting, we would also like
en/volunteer.wml  733) to be able to update other
en/volunteer.wml  734) applications included in the bundled installers, such as Polipo and
en/volunteer.wml  735) Vidalia itself.
en/volunteer.wml  736) <br />
en/volunteer.wml  737) To complete this project, the student will first need to first investigate
en/volunteer.wml  738) the existing auto-update frameworks (e.g., Sparkle on OS X) to evaluate
en/volunteer.wml  739) their strengths, weaknesses, security properties, and ability to be
en/volunteer.wml  740) integrated into Vidalia. If none are found to be suitable, the student
en/volunteer.wml  741) will design their own auto-update framework, document the design, and
en/volunteer.wml  742) then discuss the design with other developers to assess any security
en/volunteer.wml  743) issues. The student will then implement their framework (or integrate
en/volunteer.wml  744) an existing one) and test it.
en/volunteer.wml  745) <br />
en/volunteer.wml  746) A person undertaking this project should have good C++ development
en/volunteer.wml  747) experience. Previous experience with Qt is helpful, but not required. One
en/volunteer.wml  748) should also have a good understanding of common security
en/volunteer.wml  749) practices, such as package signature verification. Good writing ability
en/volunteer.wml  750) is also important for this project, since a vital step of the project
en/volunteer.wml  751) will be producing a design document to review and discuss
en/volunteer.wml  752) with others prior to implementation.
en/volunteer.wml  753) </li>
en/volunteer.wml  754) -->
en/volunteer.wml  755) 
en/volunteer.wml  756) <!-- Jake already did most of this.
en/volunteer.wml  757) <li>
en/volunteer.wml  758) <b>Improvements on our active browser configuration tester</b> -
en/volunteer.wml  759) <a href="https://check.torproject.org/">https://check.torproject.org/</a>
en/volunteer.wml  760) <br />
en/volunteer.wml  761) We currently have a functional web page to detect if Tor is working. It
en/volunteer.wml  762) has a few places where it falls short. It requires improvements with
en/volunteer.wml  763) regard to default languages and functionality. It currently only responds
en/volunteer.wml  764) in English. In addition, it is a hack of a perl script that should have
en/volunteer.wml  765) never seen the light of day. It should probably be rewritten in python
en/volunteer.wml  766) with multi-lingual support in mind. It currently uses the <a
en/volunteer.wml  767) href="http://exitlist.torproject.org/">Tor DNS exit list</a>
en/volunteer.wml  768) and should continue to do so in the future. It currently result in certain
en/volunteer.wml  769) false positives and these should be discovered, documented, and fixed
en/volunteer.wml  770) where possible. Anyone working on this project should be interested in
en/volunteer.wml  771) DNS, basic perl or preferably python programming skills, and will have
en/volunteer.wml  772) to interact minimally with Tor to test their code.
en/volunteer.wml  773) <br />
en/volunteer.wml  774) If you want to make the project more exciting
en/volunteer.wml  775) and involve more design and coding, take a look at <a
en/volunteer.wml  776) href="<svnsandbox>doc/spec/proposals/131-verify-tor-usage.txt">proposal
en/volunteer.wml  777) 131-verify-tor-usage.txt</a>.
en/volunteer.wml  778) </li>
en/volunteer.wml  779) -->
en/volunteer.wml  780) 

en/volunteer.wml  781) <!-- If we decide to switch to the exit list in TorStatus, this is obsolete.

en/volunteer.wml  782) <li>

en/volunteer.wml  783) <b>Improvements on our DNS Exit List service</b> -

en/volunteer.wml  784) <a href="http://exitlist.torproject.org/">http://exitlist.torproject.org/</a>

en/volunteer.wml  785) <br />

en/volunteer.wml  786) The <a href="http://p56soo2ibjkx23xo.onion/">exitlist software</a>
en/volunteer.wml  787) is written by our fabulous anonymous

en/volunteer.wml  788) contributer Tup. It's a DNS server written in Haskell that supports part of our <a

en/volunteer.wml  789) href="<svnsandbox>doc/contrib/torel-design.txt">exitlist

en/volunteer.wml  790) design document</a>. Currently, it is functional and it is used by

en/volunteer.wml  791) check.torproject.org and other users. The issues that are outstanding
en/volunteer.wml  792) are mostly aesthetic. This wonderful service could use a much better
en/volunteer.wml  793) website using the common Tor theme. It would be best served with better
en/volunteer.wml  794) documentation for common services that use an RBL. It could use more
en/volunteer.wml  795) publicity. A person working on this project should be interested in DNS,
en/volunteer.wml  796) basic RBL configuration for popular services, and writing documentation.
en/volunteer.wml  797) The person would require minimal Tor interaction — testing their
en/volunteer.wml  798) own documentation at the very least. Furthermore, it would be useful

en/volunteer.wml  799) if they were interested in Haskell and wanted to implement more of the

en/volunteer.wml  800) torel-design.txt suggestions.
en/volunteer.wml  801) </li>

en/volunteer.wml  802) -->

en/volunteer.wml  803) 

en/volunteer.wml  804) <!-- Nobody wanted to keep this.

en/volunteer.wml  805) <li>

en/volunteer.wml  806) <b>Testing integration of Tor with web browsers for our end users</b>

en/volunteer.wml  807) <br />

en/volunteer.wml  808) The Tor project currently lacks a solid test suite to ensure that a
en/volunteer.wml  809) user has a properly and safely configured web browser. It should test for as

en/volunteer.wml  810) many known issues as possible. It should attempt to decloak the

en/volunteer.wml  811) user in any way possible. Two current webpages that track these

en/volunteer.wml  812) kinds of issues are run by Greg Fleischer and HD Moore. Greg keeps a nice <a

en/volunteer.wml  813) href="http://pseudo-flaw.net/tor/torbutton/">list of issues along
en/volunteer.wml  814) with their proof of concept code, bug issues, etc</a>. HD Moore runs

en/volunteer.wml  815) the <a href="http://www.decloak.net/">metasploit

en/volunteer.wml  816) decloak website</a>. A person interested in defending Tor could start

en/volunteer.wml  817) by collecting as many workable and known methods for decloaking a

en/volunteer.wml  818) Tor user. (<a href="https://torcheck.xenobite.eu/">This page</a> may

en/volunteer.wml  819) be helpful as a start.) One should be familiar with the common pitfalls but

en/volunteer.wml  820) possibly have new methods in mind for implementing decloaking issues. The
en/volunteer.wml  821) website should ensure that it tells a user what their problem is. It
en/volunteer.wml  822) should help them to fix the problem or direct them to the proper support

en/volunteer.wml  823) channels. The person should also be closely familiar with using Tor and how

en/volunteer.wml  824) to prevent Tor information leakage.

en/volunteer.wml  825) </li>

en/volunteer.wml  826) -->

en/volunteer.wml  827) 

en/volunteer.wml  828) <!-- Nick did quite some work here. Is this project still required then?

en/volunteer.wml  829) <li>

en/volunteer.wml  830) <b>Libevent and Tor integration improvements</b>
en/volunteer.wml  831) <br />

en/volunteer.wml  832) Tor should make better use of the more recent features of Niels
en/volunteer.wml  833) Provos's <a href="http://monkey.org/~provos/libevent/">Libevent</a>

en/volunteer.wml  834) library.  Tor already uses Libevent for its low-level asynchronous IO

en/volunteer.wml  835) calls, and could also use Libevent's increasingly good implementations

en/volunteer.wml  836) of network buffers and of HTTP.  This wouldn't be simply a matter of

en/volunteer.wml  837) replacing Tor's internal calls with calls to Libevent: instead, we'll

en/volunteer.wml  838) need to refactor Tor to use Libevent calls that do not follow the

en/volunteer.wml  839) same models as Tor's existing backends. Also, we'll need to add
en/volunteer.wml  840) missing functionality to Libevent as needed — most difficult likely
en/volunteer.wml  841) will be adding OpenSSL support on top of Libevent's buffer abstraction.
en/volunteer.wml  842) Also tricky will be adding rate-limiting to Libevent.

en/volunteer.wml  843) </li>

en/volunteer.wml  844) -->

en/volunteer.wml  845) 

en/volunteer.wml  846) <!--

en/volunteer.wml  847) <li>

en/volunteer.wml  848) <b>Improving the Tor QA process: Continuous Integration for Windows builds</b>
en/volunteer.wml  849) <br />

en/volunteer.wml  850) It would be useful to have automated build processes for Windows and
en/volunteer.wml  851) probably other platforms. The purpose of having a continuous integration
en/volunteer.wml  852) build environment is to ensure that Windows isn't left behind for any of
en/volunteer.wml  853) the software projects used in the Tor project or its accompanying.<br />
en/volunteer.wml  854) Buildbot may be a good choice for this as it appears to support all of

en/volunteer.wml  855) the platforms Tor does. See the

en/volunteer.wml  856) <a href="http://en.wikipedia.org/wiki/BuildBot">wikipedia entry for

en/volunteer.wml  857) buildbot</a>.<br />
en/volunteer.wml  858) There may be better options and the person undertaking this task should

en/volunteer.wml  859) evaluate other options. Any person working on this automatic build
en/volunteer.wml  860) process should have experience or be willing to learn how to build all
en/volunteer.wml  861) of the respective Tor related code bases from scratch. Furthermore, the
en/volunteer.wml  862) person should have some experience building software in Windows
en/volunteer.wml  863) environments as this is the target audience we want to ensure we do not
en/volunteer.wml  864) leave behind. It would require close work with the Tor source code but
en/volunteer.wml  865) probably only in the form of building, not authoring.<br />
en/volunteer.wml  866) Additionally, we need to automate our performance testing for all platforms.
en/volunteer.wml  867) We've got buildbot (except on Windows &mdash; as noted above) to automate
en/volunteer.wml  868) our regular integration and compile testing already,
en/volunteer.wml  869) but we need to get our network simulation tests (as built in torflow)
en/volunteer.wml  870) updated for more recent versions of Tor, and designed to launch a test
en/volunteer.wml  871) network either on a single machine, or across several, so we can test
en/volunteer.wml  872) changes in performance on machines in different roles automatically.

en/volunteer.wml  873) </li>

en/volunteer.wml  874) -->

en/volunteer.wml  875) 

en/volunteer.wml  876) <!-- Removed, unless Mike still wants this to be in.

en/volunteer.wml  877) <li>
en/volunteer.wml  878) <b>Torbutton improvements</b>
en/volunteer.wml  879) <br />
en/volunteer.wml  880) Torbutton has a number of improvements that can be made in the post-1.2
en/volunteer.wml  881) timeframe. Most of these are documented as feature requests in the <a

en/volunteer.wml  882) href="https://bugs.torproject.org/flyspray/index.php?tasks=all&project=5">Torbutton

en/volunteer.wml  883) flyspray section</a>. Good examples include: stripping off node.exit on http
en/volunteer.wml  884) headers, more fine-grained control over formfill blocking, improved referrer

en/volunteer.wml  885) spoofing based on the domain of the site (a-la <a

en/volunteer.wml  886) href="https://addons.mozilla.org/en-US/firefox/addon/953">refcontrol extension</a>),

en/volunteer.wml  887) tighter integration with Vidalia for reporting Tor status, a New Identity
en/volunteer.wml  888) button with Tor integration and multiple identity management, and anything

en/volunteer.wml  889) else you might think of.

en/volunteer.wml  890) <br />
en/volunteer.wml  891) This work would be independent coding in Javascript and the fun world of <a
en/volunteer.wml  892) href="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">XUL</a>,
en/volunteer.wml  893) with not too much involvement in the Tor internals.

en/volunteer.wml  894) </li>

en/volunteer.wml  895) -->

en/volunteer.wml  896) 

en/volunteer.wml  897) <!-- Is Blossom development still happening?

en/volunteer.wml  898) <li>
en/volunteer.wml  899) <b>Rework and extend Blossom</b>
en/volunteer.wml  900) <br />
en/volunteer.wml  901) Rework and extend Blossom (a tool for monitoring and
en/volunteer.wml  902) selecting appropriate Tor circuits based upon exit node requirements
en/volunteer.wml  903) specified by the user) to gather data in a self-contained way, with
en/volunteer.wml  904) parameters easily configurable by the user.  Blossom is presently
en/volunteer.wml  905) implemented as a single Python script that interfaces with Tor using the
en/volunteer.wml  906) Controller interface and depends upon metadata about Tor nodes obtained
en/volunteer.wml  907) via external processes, such as a webpage indicating status of the nodes
en/volunteer.wml  908) plus publically available data from DNS, whois, etc.  This project has
en/volunteer.wml  909) two parts: (1) Determine which additional metadata may be useful and
en/volunteer.wml  910) rework Blossom so that it cleanly obtains the metadata on its own rather
en/volunteer.wml  911) than depend upon external scripts (this may, for example, involve
en/volunteer.wml  912) additional threads or inter-process communication), and (2) develop a
en/volunteer.wml  913) means by which the user can easily configure Blossom, starting with a
en/volunteer.wml  914) configuration file and possibly working up to a web configuration engine.

en/volunteer.wml  915) Knowledge of Tor and Python are important; knowledge of
en/volunteer.wml  916) TCP, interprocess communication, and Perl will also be helpful.  An
en/volunteer.wml  917) interest in network neutrality is important as well, since the
en/volunteer.wml  918) principles of evaluating and understanding internet inconsistency are at
en/volunteer.wml  919) the core of the Blossom effort.

en/volunteer.wml  920) </li>
en/volunteer.wml  921) 
en/volunteer.wml  922) <li>
en/volunteer.wml  923) <b>Improve Blossom: Allow users to qualitatively describe exit nodes they desire</b>
en/volunteer.wml  924) <br />
en/volunteer.wml  925) Develop and implement a means of affording Blossom
en/volunteer.wml  926) users the ability to qualitatively describe the exit node that they
en/volunteer.wml  927) want.  The Internet is an inconsistent place: some Tor exit nodes see
en/volunteer.wml  928) the world differently than others.  As presently implemented, Blossom (a
en/volunteer.wml  929) tool for monitoring and selecting appropriate Tor circuits based upon
en/volunteer.wml  930) exit node requirements specified by the user) lacks a sufficiently rich
en/volunteer.wml  931) language to describe how the different vantage points are different.
en/volunteer.wml  932) For example, some exit nodes may have an upstream network that filters
en/volunteer.wml  933) certain kinds of traffic or certain websites.  Other exit nodes may
en/volunteer.wml  934) provide access to special content as a result of their location, perhaps
en/volunteer.wml  935) as a result of discrimination on the part of the content providers
en/volunteer.wml  936) themselves.  This project has two parts: (1) develop a language for
en/volunteer.wml  937) describing characteristics of networks in which exit nodes reside, and
en/volunteer.wml  938) (2) incorporate this language into Blossom so that users can select Tor
en/volunteer.wml  939) paths based upon the description.

en/volunteer.wml  940) Knowledge of Tor and Python are important; knowledge of
en/volunteer.wml  941) TCP, interprocess communication, and Perl will also be helpful.  An
en/volunteer.wml  942) interest in network neutrality is important as well, since the
en/volunteer.wml  943) principles of evaluating and understanding internet inconsistency are at
en/volunteer.wml  944) the core of the Blossom effort.

en/volunteer.wml  945) </li>

en/volunteer.wml  946) -->

en/volunteer.wml  947) 

en/volunteer.wml  948) <!-- not really suited for GSoC; integrated into TBB for Linux/Mac OS X

en/volunteer.wml  949) <li>
en/volunteer.wml  950) <b>Usability testing of Tor</b>
en/volunteer.wml  951) <br />

en/volunteer.wml  952) Priority: <i>Medium</i>
en/volunteer.wml  953) <br />
en/volunteer.wml  954) Effort Level: <i>Medium</i>
en/volunteer.wml  955) <br />
en/volunteer.wml  956) Skill Level: <i>Low to Medium</i>
en/volunteer.wml  957) <br />
en/volunteer.wml  958) Likely Mentors: <i>Andrew</i>
en/volunteer.wml  959) <br />

en/volunteer.wml  960) Especially the browser bundle, ideally amongst our target demographic.
en/volunteer.wml  961) That would help a lot in knowing what needs to be done in terms of bug
en/volunteer.wml  962) fixes or new features. We get this informally at the moment, but a more
en/volunteer.wml  963) structured process would be better.
en/volunteer.wml  964) </li>

en/volunteer.wml  965) -->

en/volunteer.wml  966) 

en/volunteer.wml  967) </ol>
en/volunteer.wml  968) 

en/volunteer.wml  969) <a id="OtherCoding"></a>
en/volunteer.wml  970) <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>

volunteer.html    971) <ol>

en/volunteer.wml  972) <li>Tor relays don't work well on Windows XP. On

en/volunteer.wml  973) Windows, Tor uses the standard <tt>select()</tt> system

en/volunteer.wml  974) call, which uses space in the non-page pool. This means

en/volunteer.wml  975) that a medium sized Tor relay will empty the non-page pool, <a

en/volunteer.wml  976) href="https://wiki.torproject.org/noreply/TheOnionRouter/WindowsBufferProblems">causing

en/volunteer.wml  977) havoc and system crashes</a>. We should probably be using overlapped IO

en/volunteer.wml  978) instead. One solution would be to teach <a
en/volunteer.wml  979) href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
en/volunteer.wml  980) overlapped IO rather than select() on Windows, and then adapt Tor to

en/volunteer.wml  981) the new libevent interface. Christian King made a

en/volunteer.wml  982) <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good

en/volunteer.wml  983) start</a> on this in the summer of 2007.</li>

en/volunteer.wml  984) 

en/volunteer.wml  985) <li>We need to actually start building our <a href="<page
en/volunteer.wml  986) documentation>#DesignDoc">blocking-resistance design</a>. This involves

en/volunteer.wml  987) fleshing out the design, modifying many different pieces of Tor, adapting
en/volunteer.wml  988) <a href="http://vidalia-project.net/">Vidalia</a> so it supports the
en/volunteer.wml  989) new features, and planning for deployment.</li>

en/volunteer.wml  990) 

en/volunteer.wml  991) <li>We need a flexible simulator framework for studying end-to-end
en/volunteer.wml  992) traffic confirmation attacks. Many researchers have whipped up ad hoc
en/volunteer.wml  993) simulators to support their intuition either that the attacks work
en/volunteer.wml  994) really well or that some defense works great. Can we build a simulator
en/volunteer.wml  995) that's clearly documented and open enough that everybody knows it's
en/volunteer.wml  996) giving a reasonable answer? This will spur a lot of new research.
en/volunteer.wml  997) See the entry <a href="#Research">below</a> on confirmation attacks for
en/volunteer.wml  998) details on the research side of this task &mdash; who knows, when it's
en/volunteer.wml  999) done maybe you can help write a paper or three also.</li>

en/volunteer.wml 1000) 

en/volunteer.wml 1001) <li>Tor 0.1.1.x and later include support for hardware crypto accelerators

en/volunteer.wml 1002) via OpenSSL. It has been lightly tested and is possibly very buggy.  We're looking for more rigorous testing, performance analysis, and optimally, code fixes to openssl and Tor if needed.</li>

en/volunteer.wml 1003) 

volunteer.html   1004) <li>Perform a security analysis of Tor with <a
volunteer.html   1005) href="http://en.wikipedia.org/wiki/Fuzz_testing">"fuzz"</a>. Determine

en/volunteer.wml 1006) if there are good fuzzing libraries out there for what we want. Win fame by

volunteer.html   1007) getting credit when we put out a new release because of you!</li>

en/volunteer.wml 1008) 

volunteer.html   1009) <li>Tor uses TCP for transport and TLS for link
volunteer.html   1010) encryption. This is nice and simple, but it means all cells
volunteer.html   1011) on a link are delayed when a single packet gets dropped, and
volunteer.html   1012) it means we can only reasonably support TCP streams. We have a <a

en/volunteer.wml 1013) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#TransportIPnotTCP">list

en/volunteer.wml 1014) of reasons why we haven't shifted to UDP transport</a>, but it would
en/volunteer.wml 1015) be great to see that list get shorter. We also have a proposed <a

en/volunteer.wml 1016) href="<svnsandbox>doc/spec/proposals/100-tor-spec-udp.txt">specification
en/volunteer.wml 1017) for Tor and

en/volunteer.wml 1018) UDP</a> &mdash; please let us know what's wrong with it.</li>

en/volunteer.wml 1019) 

volunteer.html   1020) <li>We're not that far from having IPv6 support for destination addresses
volunteer.html   1021) (at exit nodes). If you care strongly about IPv6, that's probably the
volunteer.html   1022) first place to start.</li>

en/volunteer.wml 1023) 
en/volunteer.wml 1024) <li>We need a way to generate the website diagrams (for example, the "How
en/volunteer.wml 1025) Tor Works" pictures on the <a href="<page overview>">overview page</a>
en/volunteer.wml 1026) from source, so we can translate them as UTF-8 text rather than edit
en/volunteer.wml 1027) them by hand with Gimp. We might want to
en/volunteer.wml 1028) integrate this as an wml file so translations are easy and images are
en/volunteer.wml 1029) generated in multiple languages whenever we build the website.</li>
en/volunteer.wml 1030) 
en/volunteer.wml 1031) <li>How can we make the <a
en/volunteer.wml 1032) href="http://anonymityanywhere.com/incognito/">Incognito LiveCD</a>
en/volunteer.wml 1033) easier to maintain, improve, and document?</li>

volunteer.html   1034) </ol>
volunteer.html   1035) 

en/volunteer.wml 1036) <a id="Research"></a>
en/volunteer.wml 1037) <h2><a class="anchor" href="#Research">Research</a></h2>

volunteer.html   1038) <ol>

volunteer.html   1039) <li>The "website fingerprinting attack": make a list of a few
volunteer.html   1040) hundred popular websites, download their pages, and make a set of
volunteer.html   1041) "signatures" for each site. Then observe a Tor client's traffic. As
volunteer.html   1042) you watch him receive data, you quickly approach a guess about which
volunteer.html   1043) (if any) of those sites he is visiting. First, how effective is
volunteer.html   1044) this attack on the deployed Tor codebase? Then start exploring
volunteer.html   1045) defenses: for example, we could change Tor's cell size from 512
volunteer.html   1046) bytes to 1024 bytes, we could employ padding techniques like <a
volunteer.html   1047) href="http://freehaven.net/anonbib/#timing-fc2004">defensive dropping</a>,
volunteer.html   1048) or we could add traffic delays. How much of an impact do these have,
volunteer.html   1049) and how much usability impact (using some suitable metric) is there from
volunteer.html   1050) a successful defense in each case?</li>

volunteer.html   1051) <li>The "end-to-end traffic confirmation attack":
volunteer.html   1052) by watching traffic at Alice and at Bob, we can <a
volunteer.html   1053) href="http://freehaven.net/anonbib/#danezis:pet2004">compare
volunteer.html   1054) traffic signatures and become convinced that we're watching the same
volunteer.html   1055) stream</a>. So far Tor accepts this as a fact of life and assumes this
volunteer.html   1056) attack is trivial in all cases. First of all, is that actually true? How
volunteer.html   1057) much traffic of what sort of distribution is needed before the adversary
volunteer.html   1058) is confident he has won? Are there scenarios (e.g. not transmitting much)
volunteer.html   1059) that slow down the attack? Do some traffic padding or traffic shaping
volunteer.html   1060) schemes work better than others?</li>

en/volunteer.wml 1061) <li>A related question is: Does running a relay/bridge provide additional
en/volunteer.wml 1062) protection against these timing attacks? Can an external adversary that can't

en/volunteer.wml 1063) see inside TLS links still recognize individual streams reliably?

en/volunteer.wml 1064) Does the amount of traffic carried degrade this ability any? What if the
en/volunteer.wml 1065) client-relay deliberately delayed upstream relayed traffic to create a queue
en/volunteer.wml 1066) that could be used to mimic timings of client downstream traffic to make it
en/volunteer.wml 1067) look like it was also relayed? This same queue could also be used for masking
en/volunteer.wml 1068) timings in client upstream traffic with the techniques from <a
en/volunteer.wml 1069) href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
en/volunteer.wml 1070) but without the need for additional traffic. Would such an interleaving of
en/volunteer.wml 1071) client upstream traffic obscure timings for external adversaries? Would the
en/volunteer.wml 1072) strategies need to be adjusted for asymmetric links? For example, on
en/volunteer.wml 1073) asymmetric links, is it actually possible to differentiate client traffic from
en/volunteer.wml 1074) natural bursts due to their asymmetric capacity? Or is it easier than
en/volunteer.wml 1075) symmetric links for some other reason?</li>

en/volunteer.wml 1076) <li>Repeat Murdoch and Danezis's <a
en/volunteer.wml 1077) href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
en/volunteer.wml 1078) Oakland 05</a> on the current Tor network. See if you can learn why it
en/volunteer.wml 1079) works well on some nodes and not well on others. (My theory is that the
en/volunteer.wml 1080) fast nodes with spare capacity resist the attack better.) If that's true,
en/volunteer.wml 1081) then experiment with the RelayBandwidthRate and RelayBandwidthBurst
en/volunteer.wml 1082) options to run a relay that is used as a client while relaying the
en/volunteer.wml 1083) attacker's traffic: as we crank down the RelayBandwidthRate, does the
en/volunteer.wml 1084) attack get harder? What's the right ratio of RelayBandwidthRate to
en/volunteer.wml 1085) actually capacity? Or is it a ratio at all? While we're at it, does a
en/volunteer.wml 1086) much larger set of candidate relays increase the false positive rate
en/volunteer.wml 1087) or other complexity for the attack? (The Tor network is now almost two
en/volunteer.wml 1088) orders of magnitude larger than it was when they wrote their paper.) Be
en/volunteer.wml 1089) sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
en/volunteer.wml 1090) Clog the Queue</a> too.</li>

volunteer.html   1091) <li>The "routing zones attack": most of the literature thinks of
volunteer.html   1092) the network path between Alice and her entry node (and between the
volunteer.html   1093) exit node and Bob) as a single link on some graph. In practice,
volunteer.html   1094) though, the path traverses many autonomous systems (ASes), and <a
volunteer.html   1095) href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
volunteer.html   1096) that the same AS appears on both the entry path and the exit path</a>.
volunteer.html   1097) Unfortunately, to accurately predict whether a given Alice, entry,
volunteer.html   1098) exit, Bob quad will be dangerous, we need to download an entire Internet
volunteer.html   1099) routing zone and perform expensive operations on it. Are there practical
volunteer.html   1100) approximations, such as avoiding IP addresses in the same /8 network?</li>

en/volunteer.wml 1101) <li>Other research questions regarding geographic diversity consider
en/volunteer.wml 1102) the tradeoff between choosing an efficient circuit and choosing a random

en/volunteer.wml 1103) circuit. Look at Stephen Rollyson's <a

en/volunteer.wml 1104) href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
en/volunteer.wml 1105) paper</a> on how to discard particularly slow choices without hurting

en/volunteer.wml 1106) anonymity "too much". This line of reasoning needs more work and more
en/volunteer.wml 1107) thinking, but it looks very promising.</li>

en/volunteer.wml 1108) <li>Tor doesn't work very well when relays have asymmetric bandwidth

volunteer.html   1109) (e.g. cable or DSL). Because Tor has separate TCP connections between
volunteer.html   1110) each hop, if the incoming bytes are arriving just fine and the outgoing
volunteer.html   1111) bytes are all getting dropped on the floor, the TCP push-back mechanisms
volunteer.html   1112) don't really transmit this information back to the incoming streams.
volunteer.html   1113) Perhaps Tor should detect when it's dropping a lot of outgoing packets,
volunteer.html   1114) and rate-limit incoming streams to regulate this itself? I can imagine
volunteer.html   1115) a build-up and drop-off scheme where we pick a conservative rate-limit,
volunteer.html   1116) slowly increase it until we get lost packets, back off, repeat. We
volunteer.html   1117) need somebody who's good with networks to simulate this and help design
volunteer.html   1118) solutions; and/or we need to understand the extent of the performance
volunteer.html   1119) degradation, and use this as motivation to reconsider UDP transport.</li>
volunteer.html   1120) <li>A related topic is congestion control. Is our
volunteer.html   1121) current design sufficient once we have heavy use? Maybe
volunteer.html   1122) we should experiment with variable-sized windows rather
volunteer.html   1123) than fixed-size windows? That seemed to go well in an <a
volunteer.html   1124) href="http://www.psc.edu/networking/projects/hpn-ssh/theory.php">ssh
volunteer.html   1125) throughput experiment</a>. We'll need to measure and tweak, and maybe
volunteer.html   1126) overhaul if the results are good.</li>

en/volunteer.wml 1127) <li>Our censorship-resistance goals include preventing
en/volunteer.wml 1128) an attacker who's looking at Tor traffic on the wire from <a

en/volunteer.wml 1129) href="<svnsandbox>doc/design-paper/blocking.html#sec:network-fingerprint">distinguishing

en/volunteer.wml 1130) it from normal SSL traffic</a>. Obviously we can't achieve perfect
en/volunteer.wml 1131) steganography and still remain usable, but for a first step we'd like to
en/volunteer.wml 1132) block any attacks that can win by observing only a few packets. One of
en/volunteer.wml 1133) the remaining attacks we haven't examined much is that Tor cells are 512
en/volunteer.wml 1134) bytes, so the traffic on the wire may well be a multiple of 512 bytes.
en/volunteer.wml 1135) How much does the batching and overhead in TLS records blur this on the
en/volunteer.wml 1136) wire? Do different buffer flushing strategies in Tor affect this? Could
en/volunteer.wml 1137) a bit of padding help a lot, or is this an attack we must accept?</li>

volunteer.html   1138) <li>Tor circuits are built one hop at a time, so in theory we have the
volunteer.html   1139) ability to make some streams exit from the second hop, some from the
volunteer.html   1140) third, and so on. This seems nice because it breaks up the set of exiting

en/volunteer.wml 1141) streams that a given relay can see. But if we want each stream to be safe,

volunteer.html   1142) the "shortest" path should be at least 3 hops long by our current logic, so
volunteer.html   1143) the rest will be even longer. We need to examine this performance / security
volunteer.html   1144) tradeoff.</li>

en/volunteer.wml 1145) <li>It's not that hard to DoS Tor relays or directory authorities. Are client

volunteer.html   1146) puzzles the right answer? What other practical approaches are there? Bonus
volunteer.html   1147) if they're backward-compatible with the current Tor protocol.</li>

en/volunteer.wml 1148) <li>Programs like <a

en/volunteer.wml 1149) href="<page torbutton/index>">Torbutton</a> aim to hide

en/volunteer.wml 1150) your browser's UserAgent string by replacing it with a uniform answer for
en/volunteer.wml 1151) every Tor user. That way the attacker can't splinter Tor's anonymity set
en/volunteer.wml 1152) by looking at that header. It tries to pick a string that is commonly used
en/volunteer.wml 1153) by non-Tor users too, so it doesn't stand out. Question one: how badly
en/volunteer.wml 1154) do we hurt ourselves by periodically updating the version of Firefox
en/volunteer.wml 1155) that Torbutton claims to be? If we update it too often, we splinter the
en/volunteer.wml 1156) anonymity sets ourselves. If we don't update it often enough, then all the
en/volunteer.wml 1157) Tor users stand out because they claim to be running a quite old version
en/volunteer.wml 1158) of Firefox. The answer here probably depends on the Firefox versions seen
en/volunteer.wml 1159) in the wild. Question two: periodically people ask us to cycle through N
en/volunteer.wml 1160) UserAgent strings rather than stick with one. Does this approach help,
en/volunteer.wml 1161) hurt, or not matter? Consider: cookies and recognizing Torbutton users
en/volunteer.wml 1162) by their rotating UserAgents; malicious websites who only attack certain
en/volunteer.wml 1163) browsers; and whether the answers to question one impact this answer.
en/volunteer.wml 1164) </li>

en/volunteer.wml 1165) <li>Right now Tor clients are willing to reuse a given circuit for ten
en/volunteer.wml 1166) minutes after it's first used. The goal is to avoid loading down the
en/volunteer.wml 1167) network with too many circuit extend operations, yet to also avoid having
en/volunteer.wml 1168) clients use the same circuit for so long that the exit node can build a
en/volunteer.wml 1169) useful pseudonymous profile of them. Alas, ten minutes is probably way
en/volunteer.wml 1170) too long, especially if connections from multiple protocols (e.g. IM and
en/volunteer.wml 1171) web browsing) are put on the same circuit. If we keep fixed the overall
en/volunteer.wml 1172) number of circuit extends that the network needs to do, are there more
en/volunteer.wml 1173) efficient and/or safer ways for clients to allocate streams to circuits,
en/volunteer.wml 1174) or for clients to build preemptive circuits? Perhaps this research item
en/volunteer.wml 1175) needs to start with gathering some traces of what connections typical
en/volunteer.wml 1176) clients try to launch, so you have something realistic to try to optimize.
en/volunteer.wml 1177) </li>
en/volunteer.wml 1178) <li>How many bridge relays do you need to know to maintain
en/volunteer.wml 1179) reachability? We should measure the churn in our bridges. If there is
en/volunteer.wml 1180) lots of churn, are there ways to keep bridge users more likely to stay
en/volunteer.wml 1181) connected?
en/volunteer.wml 1182) </li>

volunteer.html   1183) </ol>
volunteer.html   1184) 

en/volunteer.wml 1185) <p>

en/volunteer.wml 1186) <a href="<page contact>">Let us know</a> if you've made progress on any
en/volunteer.wml 1187) of these!

en/volunteer.wml 1188) </p>

volunteer.html   1189) 

en/volunteer.wml 1190)   </div><!-- #main -->

volunteer.html   1191) 

en/volunteer.wml 1192) #include <foot.wmi>