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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) <!-- Mike is already working on this.

en/volunteer.wml  117) <li>

en/volunteer.wml  118) <b>Tor Node Scanner improvements</b>

en/volunteer.wml  119) <br />

en/volunteer.wml  120) Similar to the SoaT exit scanner (or perhaps even during exit scanning),

en/volunteer.wml  121) statistics can be gathered about the reliability of nodes. Nodes that
en/volunteer.wml  122) fail too high a percentage of their circuits should not be given
en/volunteer.wml  123) Guard status. Perhaps they should have their reported bandwidth
en/volunteer.wml  124) penalized by some ratio as well, or just get marked as Invalid. In
en/volunteer.wml  125) addition, nodes that exhibit a very low average stream capacity but
en/volunteer.wml  126) advertise a very high node bandwidth can also be marked as Invalid.
en/volunteer.wml  127) Much of this statistics gathering is already done, it just needs to be
en/volunteer.wml  128) transformed into something that can be reported to the Directory
en/volunteer.wml  129) Authorities to blacklist/penalize nodes in such a way that clients
en/volunteer.wml  130) will listen.

en/volunteer.wml  131) <br />

en/volunteer.wml  132) In addition, these same statistics can be gathered about the traffic
en/volunteer.wml  133) through a node. Events can be added to the <a

en/volunteer.wml  134) href="https://svn.torproject.org/svn/torctl/trunk/doc/howto.txt">Tor Control

en/volunteer.wml  135) Protocol</a> to
en/volunteer.wml  136) report if a circuit extend attempt through the node succeeds or fails, and
en/volunteer.wml  137) passive statistics can be gathered on both bandwidth and reliability
en/volunteer.wml  138) of other nodes via a node-based monitor using these events. Such a
en/volunteer.wml  139) scanner would also report information on oddly-behaving nodes to
en/volunteer.wml  140) the Directory Authorities, but a communication channel for this
en/volunteer.wml  141) currently does not exist and would need to be developed as well.
en/volunteer.wml  142) </li>

en/volunteer.wml  143) -->

en/volunteer.wml  144) 
en/volunteer.wml  145) <li>
en/volunteer.wml  146) <b>Help track the overall Tor Network status</b>

en/volunteer.wml  147) <br />

en/volunteer.wml  148) Priority: <i>Medium to High</i>
en/volunteer.wml  149) <br />
en/volunteer.wml  150) Effort Level: <i>Medium</i>
en/volunteer.wml  151) <br />
en/volunteer.wml  152) Skill Level: <i>Medium</i>
en/volunteer.wml  153) <br />
en/volunteer.wml  154) Likely Mentors: <i>Karsten</i>
en/volunteer.wml  155) <br />

en/volunteer.wml  156) It would be great to set up an automated system for tracking network
en/volunteer.wml  157) health over time, graphing it, etc. Part of this project would involve
en/volunteer.wml  158) inventing better metrics for assessing network health and growth. Is the
en/volunteer.wml  159) average uptime of the network increasing? How many relays are qualifying
en/volunteer.wml  160) for Guard status this month compared to last month? What's the turnover
en/volunteer.wml  161) in terms of new relays showing up and relays shutting off? Periodically
en/volunteer.wml  162) people collect brief snapshots, but where it gets really interesting is
en/volunteer.wml  163) when we start tracking data points over time.
en/volunteer.wml  164) <br />

en/volunteer.wml  165) Data could be collected from the Tor Network Scanners in <a
en/volunteer.wml  166) href="https://svn.torproject.org/svn/torflow/trunk/README">TorFlow</a>, from

en/volunteer.wml  167) the server descriptors that each relay publishes, and from other
en/volunteer.wml  168) sources. Results over time could be integrated into one of the <a
en/volunteer.wml  169) href="https://torstatus.blutmagie.de/">Tor Status</a> web pages, or be
en/volunteer.wml  170) kept separate. Speaking of the Tor Status pages, take a look at Roger's
en/volunteer.wml  171) <a href="http://archives.seul.org/or/talk/Jan-2008/msg00300.html">Tor
en/volunteer.wml  172) Status wish list</a>.
en/volunteer.wml  173) </li>
en/volunteer.wml  174) 

en/volunteer.wml  175) <!-- Is this still a useful project? If so, move it to another section.

en/volunteer.wml  176) <li>
en/volunteer.wml  177) <b>Better Debian/Ubuntu Packaging for Tor+Vidalia</b>

en/volunteer.wml  178) <br />
en/volunteer.wml  179) Vidalia currently doesn't play nicely on Debian and Ubuntu with the
en/volunteer.wml  180) default Tor packages. The current Tor packages automatically start Tor
en/volunteer.wml  181) as a daemon running as the debian-tor user and (sensibly) do not have a

en/volunteer.wml  182) <a href="<svnsandbox>doc/spec/control-spec.txt">ControlPort</a> defined
en/volunteer.wml  183) in the default torrc. Consequently, Vidalia will try

en/volunteer.wml  184) to start its own Tor process since it could not connect to the existing

en/volunteer.wml  185) Tor, and Vidalia's Tor process will then exit with an error message

en/volunteer.wml  186) the user likely doesn't understand since Tor cannot bind its listening

en/volunteer.wml  187) ports — they're already in use by the original Tor daemon.

en/volunteer.wml  188) <br />
en/volunteer.wml  189) The current solution involves either telling the user to stop the
en/volunteer.wml  190) existing Tor daemon and let Vidalia start its own Tor process, or
en/volunteer.wml  191) explaining to the user how to set a control port and password in their
en/volunteer.wml  192) torrc. A better solution on Debian would be to use Tor's ControlSocket,
en/volunteer.wml  193) which allows Vidalia to talk to Tor via a Unix domain socket, and could
en/volunteer.wml  194) possibly be enabled by default in Tor's Debian packages. Vidalia can

en/volunteer.wml  195) then authenticate to Tor using filesystem-based (cookie) authentication
en/volunteer.wml  196) if the user running Vidalia is also in the debian-tor group.

en/volunteer.wml  197) <br />
en/volunteer.wml  198) This project will first involve adding support for Tor's ControlSocket
en/volunteer.wml  199) to Vidalia. The student will then develop and test Debian and Ubuntu
en/volunteer.wml  200) packages for Vidalia that conform to Debian's packaging standards and

en/volunteer.wml  201) make sure they work well with the existing Tor packages. We can also

en/volunteer.wml  202) set up an apt repository to host the new Vidalia packages.
en/volunteer.wml  203) <br />

en/volunteer.wml  204) The next challenge would be to find an intuitive usable way for Vidalia
en/volunteer.wml  205) to be able to change Tor's configuration (torrc) even though it is
en/volunteer.wml  206) located in <code>/etc/tor/torrc</code> and thus immutable. The best
en/volunteer.wml  207) idea we've come up with so far is to feed Tor a new configuration via
en/volunteer.wml  208) the ControlSocket when Vidalia starts, but that's bad because Tor starts

en/volunteer.wml  209) each boot with a different configuration than the user wants. The second
en/volunteer.wml  210) best idea

en/volunteer.wml  211) we've come up with is for Vidalia to write out a temporary torrc file
en/volunteer.wml  212) and ask the user to manually move it to <code>/etc/tor/torrc</code>,
en/volunteer.wml  213) but that's bad because users shouldn't have to mess with files directly.
en/volunteer.wml  214) <br />

en/volunteer.wml  215) A person undertaking this project should have prior knowledge of

en/volunteer.wml  216) Debian package management and some C++ development experience. Previous
en/volunteer.wml  217) experience with Qt is helpful, but not required.
en/volunteer.wml  218) </li>

en/volunteer.wml  219) -->

en/volunteer.wml  220) 

en/volunteer.wml  221) <li>
en/volunteer.wml  222) <b>Improving Tor's ability to resist censorship</b>
en/volunteer.wml  223) <br />

en/volunteer.wml  224) Priority: <i>High</i>
en/volunteer.wml  225) <br />
en/volunteer.wml  226) Effort Level: <i>High</i>
en/volunteer.wml  227) <br />
en/volunteer.wml  228) Skill Level: <i>High</i>
en/volunteer.wml  229) <br />
en/volunteer.wml  230) Likely Mentors: <i>Nick</i>
en/volunteer.wml  231) <br />

en/volunteer.wml  232) The Tor 0.2.0.x series makes <a
en/volunteer.wml  233) href="<svnsandbox>doc/design-paper/blocking.html">significant
en/volunteer.wml  234) improvements</a> in resisting national and organizational censorship.
en/volunteer.wml  235) But Tor still needs better mechanisms for some parts of its
en/volunteer.wml  236) anti-censorship design.  For example, current Tors can only listen on a
en/volunteer.wml  237) single address/port combination at a time.  There's
en/volunteer.wml  238) <a href="<svnsandbox>doc/spec/proposals/118-multiple-orports.txt">a
en/volunteer.wml  239) proposal to address this limitation</a> and allow clients to connect
en/volunteer.wml  240) to any given Tor on multiple addresses and ports, but it needs more
en/volunteer.wml  241) work.  Another anti-censorship project (far more difficult) is to try
en/volunteer.wml  242) to make Tor more scanning-resistant.  Right now, an adversary can identify
en/volunteer.wml  243) <a href="<svnsandbox>doc/spec/proposals/125-bridges.txt">Tor bridges</a>
en/volunteer.wml  244) just by trying to connect to them, following the Tor protocol, and
en/volunteer.wml  245) seeing if they respond.  To solve this, bridges could
en/volunteer.wml  246) <a href="<svnsandbox>doc/design-paper/blocking.html#tth_sEc9.3">act like
en/volunteer.wml  247) webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
en/volunteer.wml  248) and not act like bridges until the user provides a bridge-specific key.
en/volunteer.wml  249) <br />
en/volunteer.wml  250) This project involves a lot of research and design. One of the big
en/volunteer.wml  251) challenges will be identifying and crafting approaches that can still
en/volunteer.wml  252) resist an adversary even after the adversary knows the design, and
en/volunteer.wml  253) then trading off censorship resistance with usability and robustness.
en/volunteer.wml  254) </li>
en/volunteer.wml  255) 

en/volunteer.wml  256) <!-- This should be mostly done.

en/volunteer.wml  257) <li>
en/volunteer.wml  258) <b>Tor/Polipo/Vidalia Auto-Update Framework</b>
en/volunteer.wml  259) <br />
en/volunteer.wml  260) We're in need of a good authenticated-update framework.
en/volunteer.wml  261) Vidalia already has the ability to notice when the user is running an
en/volunteer.wml  262) outdated or unrecommended version of Tor, using signed statements inside
en/volunteer.wml  263) the Tor directory information. Currently, Vidalia simply pops
en/volunteer.wml  264) up a little message box that lets the user know they should manually
en/volunteer.wml  265) upgrade. The goal of this project would be to extend Vidalia with the
en/volunteer.wml  266) ability to also fetch and install the updated Tor software for the
en/volunteer.wml  267) user. We should do the fetches via Tor when possible, but also fall back
en/volunteer.wml  268) to direct fetches in a smart way. Time permitting, we would also like
en/volunteer.wml  269) to be able to update other
en/volunteer.wml  270) applications included in the bundled installers, such as Polipo and
en/volunteer.wml  271) Vidalia itself.
en/volunteer.wml  272) <br />
en/volunteer.wml  273) To complete this project, the student will first need to first investigate
en/volunteer.wml  274) the existing auto-update frameworks (e.g., Sparkle on OS X) to evaluate
en/volunteer.wml  275) their strengths, weaknesses, security properties, and ability to be
en/volunteer.wml  276) integrated into Vidalia. If none are found to be suitable, the student
en/volunteer.wml  277) will design their own auto-update framework, document the design, and
en/volunteer.wml  278) then discuss the design with other developers to assess any security
en/volunteer.wml  279) issues. The student will then implement their framework (or integrate
en/volunteer.wml  280) an existing one) and test it.
en/volunteer.wml  281) <br />

en/volunteer.wml  282) A person undertaking this project should have good C++ development
en/volunteer.wml  283) experience. Previous experience with Qt is helpful, but not required. One
en/volunteer.wml  284) should also have a good understanding of common security

en/volunteer.wml  285) practices, such as package signature verification. Good writing ability
en/volunteer.wml  286) is also important for this project, since a vital step of the project

en/volunteer.wml  287) will be producing a design document to review and discuss
en/volunteer.wml  288) with others prior to implementation.

en/volunteer.wml  289) </li>

en/volunteer.wml  290) -->

en/volunteer.wml  291) 
en/volunteer.wml  292) <li>
en/volunteer.wml  293) <b>An Improved and More Usable Network Map in Vidalia</b>
en/volunteer.wml  294) <br />

en/volunteer.wml  295) Priority: <i>Medium</i>
en/volunteer.wml  296) <br />
en/volunteer.wml  297) Effort Level: <i>Medium</i>
en/volunteer.wml  298) <br />
en/volunteer.wml  299) Skill Level: <i>Medium</i>
en/volunteer.wml  300) <br />
en/volunteer.wml  301) Likely Mentors: <i>Matt</i>
en/volunteer.wml  302) <br />

en/volunteer.wml  303) One of Vidalia's existing features is a network map that shows the user
en/volunteer.wml  304) the approximate geographic location of relays in the Tor network and
en/volunteer.wml  305) plots the paths the user's traffic takes as it is tunneled through the
en/volunteer.wml  306) Tor network. The map is currently not very interactive and has rather

en/volunteer.wml  307) poor graphics. Instead, we implemented KDE's Marble widget such
en/volunteer.wml  308) that it gives us a better quality map and enables improved interactivity,

en/volunteer.wml  309) such as allowing the user to click on individual relays or circuits to

en/volunteer.wml  310) display additional information. We want to add the ability

en/volunteer.wml  311) for users to click on a particular relay or a country containing one or

en/volunteer.wml  312) more Tor exit relays and say, "I want my connections to exit

en/volunteer.wml  313) from here."
en/volunteer.wml  314) <br />

en/volunteer.wml  315) This project will first involve getting familiar with Vidalia
en/volunteer.wml  316) and the Marble widget's API. One will then integrate the widget

en/volunteer.wml  317) into Vidalia and customize Marble to be better suited for our application,
en/volunteer.wml  318) such as making circuits clickable, storing cached map data in Vidalia's
en/volunteer.wml  319) own data directory, and customizing some of the widget's dialogs.
en/volunteer.wml  320) <br />

en/volunteer.wml  321) A person undertaking this project should have good C++ development

en/volunteer.wml  322) experience. Previous experience with Qt and CMake is helpful, but not
en/volunteer.wml  323) required.
en/volunteer.wml  324) </li>
en/volunteer.wml  325) 

en/volunteer.wml  326) <li>

en/volunteer.wml  327) <b>Tor Controller Status Event Interface</b>

en/volunteer.wml  328) <br />

en/volunteer.wml  329) Priority: <i>Medium</i>
en/volunteer.wml  330) <br />
en/volunteer.wml  331) Effort Level: <i>Medium</i>
en/volunteer.wml  332) <br />
en/volunteer.wml  333) Skill Level: <i>Medium</i>
en/volunteer.wml  334) <br />
en/volunteer.wml  335) Likely Mentors: <i>Matt</i>
en/volunteer.wml  336) <br />

en/volunteer.wml  337) There are a number of status changes inside Tor of which the user may need

en/volunteer.wml  338) to be informed. For example, if the user is trying to set up his Tor as a
en/volunteer.wml  339) relay and Tor decides that its ports are not reachable from outside

en/volunteer.wml  340) the user's network, we should alert the user. Currently, all the user

en/volunteer.wml  341) gets is a couple log messages in Vidalia's 'message log' window, which they

en/volunteer.wml  342) likely never see since they don't receive a notification that something
en/volunteer.wml  343) has gone wrong. Even if the user does actually look at the message log,
en/volunteer.wml  344) most of the messages make little sense to the novice user.
en/volunteer.wml  345) <br />
en/volunteer.wml  346) Tor has the ability to inform Vidalia of many such status changes, and
en/volunteer.wml  347) we recently implemented support for a couple of these events. Still,
en/volunteer.wml  348) there are many more status events the user should be informed of and we
en/volunteer.wml  349) need a better UI for actually displaying them to the user.
en/volunteer.wml  350) <br />
en/volunteer.wml  351) The goal of this project then is to design and implement a UI for
en/volunteer.wml  352) displaying Tor status events to the user. For example, we might put a
en/volunteer.wml  353) little badge on Vidalia's tray icon that alerts the user to new status
en/volunteer.wml  354) events they should look at. Double-clicking the icon could bring up a
en/volunteer.wml  355) dialog that summarizes recent status events in simple terms and maybe

en/volunteer.wml  356) suggests a remedy for any negative events if they can be corrected by

en/volunteer.wml  357) the user. Of course, this is just an example and one is free to

en/volunteer.wml  358) suggest another approach.
en/volunteer.wml  359) <br />

en/volunteer.wml  360) A person undertaking this project should have good UI design and layout

en/volunteer.wml  361) and some C++ development experience. Previous experience with Qt and

en/volunteer.wml  362) Qt's Designer will be very helpful, but are not required. Some

en/volunteer.wml  363) English writing ability will also be useful, since this project will
en/volunteer.wml  364) likely involve writing small amounts of help documentation that should
en/volunteer.wml  365) be understandable by non-technical users. Bonus points for some graphic
en/volunteer.wml  366) design/Photoshop fu, since we might want/need some shiny new icons too.
en/volunteer.wml  367) </li>
en/volunteer.wml  368) 

en/volunteer.wml  369) <!-- Jake already did most of this.

en/volunteer.wml  370) <li>

en/volunteer.wml  371) <b>Improvements on our active browser configuration tester</b> -

en/volunteer.wml  372) <a href="https://check.torproject.org/">https://check.torproject.org/</a>

en/volunteer.wml  373) <br />
en/volunteer.wml  374) We currently have a functional web page to detect if Tor is working. It

en/volunteer.wml  375) has a few places where it falls short. It requires improvements with

en/volunteer.wml  376) regard to default languages and functionality. It currently only responds
en/volunteer.wml  377) in English. In addition, it is a hack of a perl script that should have
en/volunteer.wml  378) never seen the light of day. It should probably be rewritten in python

en/volunteer.wml  379) with multi-lingual support in mind. It currently uses the <a
en/volunteer.wml  380) href="http://exitlist.torproject.org/">Tor DNS exit list</a>
en/volunteer.wml  381) and should continue to do so in the future. It currently result in certain

en/volunteer.wml  382) false positives and these should be discovered, documented, and fixed
en/volunteer.wml  383) where possible. Anyone working on this project should be interested in

en/volunteer.wml  384) DNS, basic perl or preferably python programming skills, and will have

en/volunteer.wml  385) to interact minimally with Tor to test their code.

en/volunteer.wml  386) <br />
en/volunteer.wml  387) If you want to make the project more exciting
en/volunteer.wml  388) and involve more design and coding, take a look at <a
en/volunteer.wml  389) href="<svnsandbox>doc/spec/proposals/131-verify-tor-usage.txt">proposal
en/volunteer.wml  390) 131-verify-tor-usage.txt</a>.

en/volunteer.wml  391) </li>

en/volunteer.wml  392) -->

en/volunteer.wml  393) 

en/volunteer.wml  394) <!-- If we decide to switch to the exit list in TorStatus, this is obsolete.

en/volunteer.wml  395) <li>

en/volunteer.wml  396) <b>Improvements on our DNS Exit List service</b> -

en/volunteer.wml  397) <a href="http://exitlist.torproject.org/">http://exitlist.torproject.org/</a>

en/volunteer.wml  398) <br />

en/volunteer.wml  399) The <a href="http://p56soo2ibjkx23xo.onion/">exitlist software</a>
en/volunteer.wml  400) is written by our fabulous anonymous

en/volunteer.wml  401) contributer Tup. It's a DNS server written in Haskell that supports part of our <a

en/volunteer.wml  402) href="<svnsandbox>doc/contrib/torel-design.txt">exitlist

en/volunteer.wml  403) design document</a>. Currently, it is functional and it is used by

en/volunteer.wml  404) check.torproject.org and other users. The issues that are outstanding
en/volunteer.wml  405) are mostly aesthetic. This wonderful service could use a much better
en/volunteer.wml  406) website using the common Tor theme. It would be best served with better
en/volunteer.wml  407) documentation for common services that use an RBL. It could use more
en/volunteer.wml  408) publicity. A person working on this project should be interested in DNS,
en/volunteer.wml  409) basic RBL configuration for popular services, and writing documentation.
en/volunteer.wml  410) The person would require minimal Tor interaction — testing their
en/volunteer.wml  411) own documentation at the very least. Furthermore, it would be useful

en/volunteer.wml  412) if they were interested in Haskell and wanted to implement more of the

en/volunteer.wml  413) torel-design.txt suggestions.
en/volunteer.wml  414) </li>

en/volunteer.wml  415) -->

en/volunteer.wml  416) 

en/volunteer.wml  417) <!-- Nobody wanted to keep this.

en/volunteer.wml  418) <li>

en/volunteer.wml  419) <b>Testing integration of Tor with web browsers for our end users</b>

en/volunteer.wml  420) <br />

en/volunteer.wml  421) The Tor project currently lacks a solid test suite to ensure that a
en/volunteer.wml  422) user has a properly and safely configured web browser. It should test for as

en/volunteer.wml  423) many known issues as possible. It should attempt to decloak the

en/volunteer.wml  424) user in any way possible. Two current webpages that track these

en/volunteer.wml  425) kinds of issues are run by Greg Fleischer and HD Moore. Greg keeps a nice <a

en/volunteer.wml  426) href="http://pseudo-flaw.net/tor/torbutton/">list of issues along
en/volunteer.wml  427) with their proof of concept code, bug issues, etc</a>. HD Moore runs

en/volunteer.wml  428) the <a href="http://www.decloak.net/">metasploit

en/volunteer.wml  429) decloak website</a>. A person interested in defending Tor could start

en/volunteer.wml  430) by collecting as many workable and known methods for decloaking a

en/volunteer.wml  431) Tor user. (<a href="https://torcheck.xenobite.eu/">This page</a> may

en/volunteer.wml  432) be helpful as a start.) One should be familiar with the common pitfalls but

en/volunteer.wml  433) possibly have new methods in mind for implementing decloaking issues. The
en/volunteer.wml  434) website should ensure that it tells a user what their problem is. It
en/volunteer.wml  435) should help them to fix the problem or direct them to the proper support

en/volunteer.wml  436) channels. The person should also be closely familiar with using Tor and how

en/volunteer.wml  437) to prevent Tor information leakage.

en/volunteer.wml  438) </li>

en/volunteer.wml  439) -->

en/volunteer.wml  440) 

en/volunteer.wml  441) <!-- Nick did quite some work here. Is this project still required then?

en/volunteer.wml  442) <li>

en/volunteer.wml  443) <b>Libevent and Tor integration improvements</b>
en/volunteer.wml  444) <br />

en/volunteer.wml  445) Tor should make better use of the more recent features of Niels
en/volunteer.wml  446) Provos's <a href="http://monkey.org/~provos/libevent/">Libevent</a>

en/volunteer.wml  447) library.  Tor already uses Libevent for its low-level asynchronous IO

en/volunteer.wml  448) calls, and could also use Libevent's increasingly good implementations

en/volunteer.wml  449) of network buffers and of HTTP.  This wouldn't be simply a matter of

en/volunteer.wml  450) replacing Tor's internal calls with calls to Libevent: instead, we'll

en/volunteer.wml  451) need to refactor Tor to use Libevent calls that do not follow the

en/volunteer.wml  452) same models as Tor's existing backends. Also, we'll need to add
en/volunteer.wml  453) missing functionality to Libevent as needed — most difficult likely
en/volunteer.wml  454) will be adding OpenSSL support on top of Libevent's buffer abstraction.
en/volunteer.wml  455) Also tricky will be adding rate-limiting to Libevent.

en/volunteer.wml  456) </li>

en/volunteer.wml  457) -->

en/volunteer.wml  458) 
en/volunteer.wml  459) <li>

en/volunteer.wml  460) <b>Tuneup Tor!</b>
en/volunteer.wml  461) <br />

en/volunteer.wml  462) Priority: <i>Medium</i>
en/volunteer.wml  463) <br />
en/volunteer.wml  464) Effort Level: <i>Medium</i>
en/volunteer.wml  465) <br />
en/volunteer.wml  466) Skill Level: <i>Medium to High</i>
en/volunteer.wml  467) <br />
en/volunteer.wml  468) Likely Mentors: <i>Nick, Roger, Mike</i>
en/volunteer.wml  469) <br />

en/volunteer.wml  470) Right now, Tor relays measure and report their own bandwidth, and Tor
en/volunteer.wml  471) clients choose which relays to use in part based on that bandwidth.
en/volunteer.wml  472) This approach is vulnerable to
en/volunteer.wml  473) <a href="http://freehaven.net/anonbib/#bauer:wpes2007">attacks where
en/volunteer.wml  474) relays lie about their bandwidth</a>;
en/volunteer.wml  475) to address this, Tor currently caps the maximum bandwidth
en/volunteer.wml  476) it's willing to believe any relay provides.  This is a limited fix, and
en/volunteer.wml  477) a waste of bandwidth capacity to boot.  Instead,

en/volunteer.wml  478) Tor should possibly measure bandwidth in a more distributed way, perhaps
en/volunteer.wml  479) as described in the

en/volunteer.wml  480) <a href="http://freehaven.net/anonbib/author.html#snader08">"A Tune-up for
en/volunteer.wml  481) Tor"</a> paper

en/volunteer.wml  482) by Snader and Borisov. One could use current testing code to

en/volunteer.wml  483) double-check this paper's findings and verify the extent to which they

en/volunteer.wml  484) dovetail with Tor as deployed in the wild, and determine good ways to
en/volunteer.wml  485) incorporate them into their suggestions Tor network without adding too

en/volunteer.wml  486) much communications overhead between relays and directory

en/volunteer.wml  487) authorities.

en/volunteer.wml  488) </li>
en/volunteer.wml  489) 

en/volunteer.wml  490) <!--

en/volunteer.wml  491) <li>

en/volunteer.wml  492) <b>Improving the Tor QA process: Continuous Integration for Windows builds</b>
en/volunteer.wml  493) <br />

en/volunteer.wml  494) It would be useful to have automated build processes for Windows and
en/volunteer.wml  495) probably other platforms. The purpose of having a continuous integration
en/volunteer.wml  496) build environment is to ensure that Windows isn't left behind for any of
en/volunteer.wml  497) the software projects used in the Tor project or its accompanying.<br />
en/volunteer.wml  498) Buildbot may be a good choice for this as it appears to support all of

en/volunteer.wml  499) the platforms Tor does. See the

en/volunteer.wml  500) <a href="http://en.wikipedia.org/wiki/BuildBot">wikipedia entry for

en/volunteer.wml  501) buildbot</a>.<br />
en/volunteer.wml  502) There may be better options and the person undertaking this task should
en/volunteer.wml  503) evaluate other options. Any person working on this automatic build
en/volunteer.wml  504) process should have experience or be willing to learn how to build all
en/volunteer.wml  505) of the respective Tor related code bases from scratch. Furthermore, the
en/volunteer.wml  506) person should have some experience building software in Windows
en/volunteer.wml  507) environments as this is the target audience we want to ensure we do not
en/volunteer.wml  508) leave behind. It would require close work with the Tor source code but

en/volunteer.wml  509) probably only in the form of building, not authoring.<br />
en/volunteer.wml  510) Additionally, we need to automate our performance testing for all platforms.

en/volunteer.wml  511) We've got buildbot (except on Windows — as noted above) to automate

en/volunteer.wml  512) our regular integration and compile testing already,
en/volunteer.wml  513) but we need to get our network simulation tests (as built in torflow)
en/volunteer.wml  514) updated for more recent versions of Tor, and designed to launch a test
en/volunteer.wml  515) network either on a single machine, or across several, so we can test

en/volunteer.wml  516) changes in performance on machines in different roles automatically.

en/volunteer.wml  517) </li>

en/volunteer.wml  518) -->

en/volunteer.wml  519) 

en/volunteer.wml  520) <li>

en/volunteer.wml  521) <b>Improve our unit testing process</b>
en/volunteer.wml  522) <br />

en/volunteer.wml  523) Priority: <i>Medium</i>
en/volunteer.wml  524) <br />
en/volunteer.wml  525) Effort Level: <i>Medium</i>
en/volunteer.wml  526) <br />
en/volunteer.wml  527) Skill Level: <i>Medium</i>
en/volunteer.wml  528) <br />
en/volunteer.wml  529) Likely Mentors: <i>Nick</i>
en/volunteer.wml  530) <br />

en/volunteer.wml  531) Tor needs to be far more tested. This is a multi-part effort. To start

en/volunteer.wml  532) with, our unit test coverage should rise substantially, especially in

en/volunteer.wml  533) the areas outside the utility functions. This will require significant

en/volunteer.wml  534) refactoring of some parts of Tor, in order to dissociate as much logic

en/volunteer.wml  535) as possible from globals.
en/volunteer.wml  536) <br />

en/volunteer.wml  537) Additionally, we need to automate our performance testing. We've got

en/volunteer.wml  538) buildbot to automate our regular integration and compile testing already
en/volunteer.wml  539) (though we need somebody to set it up on Windows),

en/volunteer.wml  540) but we need to get our network simulation tests (as built in <a
en/volunteer.wml  541) href="https://svn.torproject.org/svn/torflow/trunk/README">TorFlow</a>)

en/volunteer.wml  542) updated for more recent versions of Tor, and designed to launch a test
en/volunteer.wml  543) network either on a single machine, or across several, so we can test

en/volunteer.wml  544) changes in performance on machines in different roles automatically.

en/volunteer.wml  545) </li>
en/volunteer.wml  546) 

en/volunteer.wml  547) <li>

en/volunteer.wml  548) <b>Help revive an independent Tor client implementation</b>

en/volunteer.wml  549) <br />

en/volunteer.wml  550) Priority: <i>Medium</i>
en/volunteer.wml  551) <br />
en/volunteer.wml  552) Effort Level: <i>High</i>
en/volunteer.wml  553) <br />
en/volunteer.wml  554) Skill Level: <i>Medium to High</i>
en/volunteer.wml  555) <br />
en/volunteer.wml  556) Likely Mentors: <i>Karsten, Nick</i>
en/volunteer.wml  557) <br />

en/volunteer.wml  558) Reanimate one of the approaches to implement a Tor client in Java,
en/volunteer.wml  559) e.g. the <a href="http://onioncoffee.sourceforge.net/">OnionCoffee
en/volunteer.wml  560) project</a>, and make it run on <a
en/volunteer.wml  561) href="http://code.google.com/android/">Android</a>. The first step
en/volunteer.wml  562) would be to port the existing code and execute it in an Android
en/volunteer.wml  563) environment. Next, the code should be updated to support the newer Tor
en/volunteer.wml  564) protocol versions like the <a href="<svnsandbox>doc/spec/dir-spec.txt">v3
en/volunteer.wml  565) directory protocol</a>. Further, support for requesting or even

en/volunteer.wml  566) providing Tor hidden services would be neat, but not required.
en/volunteer.wml  567) <br />

en/volunteer.wml  568) A prospective developer should be able to understand and write new Java
en/volunteer.wml  569) code, including

en/volunteer.wml  570) a Java cryptography API. Being able to read C code would be helpful,

en/volunteer.wml  571) too. One should be willing to read the existing documentation,

en/volunteer.wml  572) implement code based on it, and refine the documentation
en/volunteer.wml  573) when things are underdocumented. This project is mostly about coding and

en/volunteer.wml  574) to a small degree about design.
en/volunteer.wml  575) </li>
en/volunteer.wml  576) 
en/volunteer.wml  577) <li>

en/volunteer.wml  578) <b>Bring moniTor to life</b>
en/volunteer.wml  579) <br />

en/volunteer.wml  580) Priority: <i>Medium</i>
en/volunteer.wml  581) <br />
en/volunteer.wml  582) Effort Level: <i>Medium</i>
en/volunteer.wml  583) <br />
en/volunteer.wml  584) Skill Level: <i>Low to Medium</i>
en/volunteer.wml  585) <br />
en/volunteer.wml  586) Likely Mentors: <i>Karsten, Jacob</i>
en/volunteer.wml  587) <br />

en/volunteer.wml  588) Implement a <a href="http://www.ss64.com/bash/top.html">top-like</a>
en/volunteer.wml  589) management tool for Tor relays. The purpose of such a tool would be
en/volunteer.wml  590) to monitor a local Tor relay via its control port and include useful
en/volunteer.wml  591) system information of the underlying machine. When running this tool, it
en/volunteer.wml  592) would dynamically update its content like top does for Linux processes.
en/volunteer.wml  593) <a href="http://archives.seul.org/or/dev/Jan-2008/msg00005.html">This

en/volunteer.wml  594) or-dev post</a> might be a good first read.
en/volunteer.wml  595) <br />

en/volunteer.wml  596) A person interested in this should be familiar

en/volunteer.wml  597) with or willing to learn about administering a Tor relay and configuring
en/volunteer.wml  598) it via its control port. As an initial prototype is written in Python,
en/volunteer.wml  599) some knowledge about writing Python code would be helpful, too. This

en/volunteer.wml  600) project is one part about identifying requirements to such a
en/volunteer.wml  601) tool and designing its interface, and one part lots of coding.

en/volunteer.wml  602) </li>
en/volunteer.wml  603) 

en/volunteer.wml  604) <!-- Removed, unless Mike still wants this to be in.

en/volunteer.wml  605) <li>
en/volunteer.wml  606) <b>Torbutton improvements</b>
en/volunteer.wml  607) <br />
en/volunteer.wml  608) Torbutton has a number of improvements that can be made in the post-1.2
en/volunteer.wml  609) timeframe. Most of these are documented as feature requests in the <a

en/volunteer.wml  610) href="https://bugs.torproject.org/flyspray/index.php?tasks=all&project=5">Torbutton

en/volunteer.wml  611) flyspray section</a>. Good examples include: stripping off node.exit on http
en/volunteer.wml  612) headers, more fine-grained control over formfill blocking, improved referrer

en/volunteer.wml  613) spoofing based on the domain of the site (a-la <a

en/volunteer.wml  614) href="https://addons.mozilla.org/en-US/firefox/addon/953">refcontrol extension</a>),

en/volunteer.wml  615) tighter integration with Vidalia for reporting Tor status, a New Identity
en/volunteer.wml  616) button with Tor integration and multiple identity management, and anything

en/volunteer.wml  617) else you might think of.

en/volunteer.wml  618) <br />
en/volunteer.wml  619) This work would be independent coding in Javascript and the fun world of <a
en/volunteer.wml  620) href="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">XUL</a>,
en/volunteer.wml  621) with not too much involvement in the Tor internals.

en/volunteer.wml  622) </li>

en/volunteer.wml  623) -->

en/volunteer.wml  624) 

en/volunteer.wml  625) <li>

en/volunteer.wml  626) <b>Improving Polipo on Windows</b>

en/volunteer.wml  627) <br />

en/volunteer.wml  628) Priority: <i>Medium</i>

en/volunteer.wml  629) <br />

en/volunteer.wml  630) Effort Level: <i>Low</i>

en/volunteer.wml  631) <br />

en/volunteer.wml  632) Skill Level: <i>Medium</i>

en/volunteer.wml  633) <br />
en/volunteer.wml  634) Likely Mentors: <i>Martin</i>
en/volunteer.wml  635) <br />

en/volunteer.wml  636) Help port <a
en/volunteer.wml  637) href="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</a> to

en/volunteer.wml  638) Windows. Example topics to tackle include:

en/volunteer.wml  639) 1) the ability to asynchronously

en/volunteer.wml  640) query name servers, find the system nameservers, and manage netbios

en/volunteer.wml  641) and dns queries.

en/volunteer.wml  642) 2) manage events and buffers

en/volunteer.wml  643) natively (i.e. in Unix-like OSes, Polipo defaults to 25% of ram, in

en/volunteer.wml  644) Windows it's whatever the config specifies). 3) some sort of GUI config

en/volunteer.wml  645) and reporting tool, bonus if it has a systray icon with right clickable
en/volunteer.wml  646) menu options. Double bonus if it's cross-platform compatible.

en/volunteer.wml  647) 3) allow the software to use the Windows Registry and handle proper Windows directory locations, such as "C:\Program Files\Polipo"

en/volunteer.wml  648) </li>
en/volunteer.wml  649) 

en/volunteer.wml  650) <!-- Is Blossom development still happening?

en/volunteer.wml  651) <li>
en/volunteer.wml  652) <b>Rework and extend Blossom</b>
en/volunteer.wml  653) <br />
en/volunteer.wml  654) Rework and extend Blossom (a tool for monitoring and
en/volunteer.wml  655) selecting appropriate Tor circuits based upon exit node requirements
en/volunteer.wml  656) specified by the user) to gather data in a self-contained way, with
en/volunteer.wml  657) parameters easily configurable by the user.  Blossom is presently
en/volunteer.wml  658) implemented as a single Python script that interfaces with Tor using the
en/volunteer.wml  659) Controller interface and depends upon metadata about Tor nodes obtained
en/volunteer.wml  660) via external processes, such as a webpage indicating status of the nodes
en/volunteer.wml  661) plus publically available data from DNS, whois, etc.  This project has
en/volunteer.wml  662) two parts: (1) Determine which additional metadata may be useful and
en/volunteer.wml  663) rework Blossom so that it cleanly obtains the metadata on its own rather
en/volunteer.wml  664) than depend upon external scripts (this may, for example, involve
en/volunteer.wml  665) additional threads or inter-process communication), and (2) develop a
en/volunteer.wml  666) means by which the user can easily configure Blossom, starting with a
en/volunteer.wml  667) configuration file and possibly working up to a web configuration engine.

en/volunteer.wml  668) Knowledge of Tor and Python are important; knowledge of
en/volunteer.wml  669) TCP, interprocess communication, and Perl will also be helpful.  An
en/volunteer.wml  670) interest in network neutrality is important as well, since the
en/volunteer.wml  671) principles of evaluating and understanding internet inconsistency are at
en/volunteer.wml  672) the core of the Blossom effort.

en/volunteer.wml  673) </li>
en/volunteer.wml  674) 
en/volunteer.wml  675) <li>
en/volunteer.wml  676) <b>Improve Blossom: Allow users to qualitatively describe exit nodes they desire</b>
en/volunteer.wml  677) <br />
en/volunteer.wml  678) Develop and implement a means of affording Blossom
en/volunteer.wml  679) users the ability to qualitatively describe the exit node that they
en/volunteer.wml  680) want.  The Internet is an inconsistent place: some Tor exit nodes see
en/volunteer.wml  681) the world differently than others.  As presently implemented, Blossom (a
en/volunteer.wml  682) tool for monitoring and selecting appropriate Tor circuits based upon
en/volunteer.wml  683) exit node requirements specified by the user) lacks a sufficiently rich
en/volunteer.wml  684) language to describe how the different vantage points are different.
en/volunteer.wml  685) For example, some exit nodes may have an upstream network that filters
en/volunteer.wml  686) certain kinds of traffic or certain websites.  Other exit nodes may
en/volunteer.wml  687) provide access to special content as a result of their location, perhaps
en/volunteer.wml  688) as a result of discrimination on the part of the content providers
en/volunteer.wml  689) themselves.  This project has two parts: (1) develop a language for
en/volunteer.wml  690) describing characteristics of networks in which exit nodes reside, and
en/volunteer.wml  691) (2) incorporate this language into Blossom so that users can select Tor
en/volunteer.wml  692) paths based upon the description.

en/volunteer.wml  693) Knowledge of Tor and Python are important; knowledge of
en/volunteer.wml  694) TCP, interprocess communication, and Perl will also be helpful.  An
en/volunteer.wml  695) interest in network neutrality is important as well, since the
en/volunteer.wml  696) principles of evaluating and understanding internet inconsistency are at
en/volunteer.wml  697) the core of the Blossom effort.

en/volunteer.wml  698) </li>

en/volunteer.wml  699) -->

en/volunteer.wml  700) 

en/volunteer.wml  701) <li>
en/volunteer.wml  702) <b>Implement a torrent-based scheme for downloading Thandy packages</b>
en/volunteer.wml  703) <br />

en/volunteer.wml  704) Priority: <i>Medium</i>
en/volunteer.wml  705) <br />
en/volunteer.wml  706) Effort Level: <i>High</i>
en/volunteer.wml  707) <br />
en/volunteer.wml  708) Skill Level: <i>Medium to High</i>
en/volunteer.wml  709) <br />

en/volunteer.wml  710) Likely Mentors: <i>Martin, Nick</i>

en/volunteer.wml  711) <br />

en/volunteer.wml  712) <a
en/volunteer.wml  713) href="http://git.torproject.org/checkout/thandy/master/specs/thandy-spec.txt">Thandy</a>

en/volunteer.wml  714) is a relatively new software to allow assisted updates of Tor and related

en/volunteer.wml  715) software. Currently, there are very few users, but we expect Thandy to be
en/volunteer.wml  716) used by almost every Tor user in the future. To avoid crashing servers on
en/volunteer.wml  717) the day of a Tor update, we need new ways to distribute new packages
en/volunteer.wml  718) efficiently, and using libtorrent seems to be a possible solution. If you
en/volunteer.wml  719) think of other good ideas, great - please do let us know!<br />
en/volunteer.wml  720) We also need to investigate how to include our mirrors better. If possible,
en/volunteer.wml  721) there should be an easy way for them to help distributing the packages.
en/volunteer.wml  722) </li>
en/volunteer.wml  723) 

en/volunteer.wml  724) <li>
en/volunteer.wml  725) <b>Torbutton equivalent for Thunderbird</b>
en/volunteer.wml  726) <br />

en/volunteer.wml  727) Priority: <i>Medium</i>
en/volunteer.wml  728) <br />
en/volunteer.wml  729) Effort Level: <i>High</i>
en/volunteer.wml  730) <br />
en/volunteer.wml  731) Skill Level: <i>High</i>
en/volunteer.wml  732) <br />
en/volunteer.wml  733) Likely Mentors: <i>Mike</i>
en/volunteer.wml  734) <br />

en/volunteer.wml  735) We're hearing from an increasing number of users that they want to use
en/volunteer.wml  736) Thunderbird with Tor. However, there are plenty of application-level
en/volunteer.wml  737) concerns, for example, by default Thunderbird will put your hostname in
en/volunteer.wml  738) the outgoing mail that it sends. At some point we should start a new
en/volunteer.wml  739) push to build a Thunderbird extension similar to Torbutton.
en/volunteer.wml  740) </li>
en/volunteer.wml  741) 

en/volunteer.wml  742) <li>
en/volunteer.wml  743) <b>New Torbutton Features</b>

en/volunteer.wml  744) <br />
en/volunteer.wml  745) Priority: <i>Medium</i>
en/volunteer.wml  746) <br />
en/volunteer.wml  747) Effort Level: <i>High</i>
en/volunteer.wml  748) <br />
en/volunteer.wml  749) Skill Level: <i>High</i>
en/volunteer.wml  750) <br />
en/volunteer.wml  751) Likely Mentors: <i>Mike</i>

en/volunteer.wml  752) <br/>
en/volunteer.wml  753) There are several <a

en/volunteer.wml  754) href="https://bugs.torproject.org/flyspray/index.php?tasks=all&project=5&type=2">good

en/volunteer.wml  755) feature requests</a> on the Torbutton Flyspray section. In particular, <a

en/volunteer.wml  756) href="https://bugs.torproject.org/flyspray/index.php?do=details&id=523">Integrating
en/volunteer.wml  757) 'New Identity' with Vidalia</a>,
en/volunteer.wml  758) <a href="https://bugs.torproject.org/flyspray/index.php?do=details&amp;id=940">ways of

en/volunteer.wml  759) managing multiple cookie jars/identities</a>, <a

en/volunteer.wml  760) href="https://bugs.torproject.org/flyspray/index.php?do=details&id=637">preserving

en/volunteer.wml  761) specific cookies</a> when cookies are cleared,

en/volunteer.wml  762) <a

en/volunteer.wml  763) href="https://bugs.torproject.org/flyspray/index.php?do=details&id=524">better

en/volunteer.wml  764) referrer spoofing</a>, <a

en/volunteer.wml  765) href="https://bugs.torproject.org/flyspray/index.php?do=details&id=564">correct

en/volunteer.wml  766) Tor status reporting</a>, and <a

en/volunteer.wml  767) href="https://bugs.torproject.org/flyspray/index.php?do=details&id=462">"tor://"

en/volunteer.wml  768) and "tors://" urls</a> are all interesting
en/volunteer.wml  769) features that could be added.
en/volunteer.wml  770) <br />
en/volunteer.wml  771) This work would be independent coding in Javascript and the fun world of <a
en/volunteer.wml  772) href="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">XUL</a>,
en/volunteer.wml  773) with not too much involvement in the Tor internals.
en/volunteer.wml  774) </li>
en/volunteer.wml  775) 

en/volunteer.wml  776) <li>
en/volunteer.wml  777) <b>Usability testing of Tor</b>
en/volunteer.wml  778) <br />

en/volunteer.wml  779) Priority: <i>Medium</i>
en/volunteer.wml  780) <br />
en/volunteer.wml  781) Effort Level: <i>Medium</i>
en/volunteer.wml  782) <br />
en/volunteer.wml  783) Skill Level: <i>Low to Medium</i>
en/volunteer.wml  784) <br />
en/volunteer.wml  785) Likely Mentors: <i>Andrew</i>
en/volunteer.wml  786) <br />

en/volunteer.wml  787) Especially the browser bundle, ideally amongst our target demographic.
en/volunteer.wml  788) That would help a lot in knowing what needs to be done in terms of bug
en/volunteer.wml  789) fixes or new features. We get this informally at the moment, but a more
en/volunteer.wml  790) structured process would be better.
en/volunteer.wml  791) </li>
en/volunteer.wml  792) 

en/volunteer.wml  793) <li>
en/volunteer.wml  794) <b>Translation wiki for our website</b>
en/volunteer.wml  795) <br />

en/volunteer.wml  796) Priority: <i>High</i>
en/volunteer.wml  797) <br />
en/volunteer.wml  798) Effort Level: <i>Medium</i>
en/volunteer.wml  799) <br />
en/volunteer.wml  800) Skill Level: <i>Medium</i>
en/volunteer.wml  801) <br />
en/volunteer.wml  802) Likely Mentors: <i>Jacob</i>
en/volunteer.wml  803) <br />

en/volunteer.wml  804) The Tor Project has been working over the past year to set up web-based
en/volunteer.wml  805) tools to help volunteers translate our applications into other languages.
en/volunteer.wml  806) We finally hit upon Pootle, and we have a fine web-based translation engine
en/volunteer.wml  807) in place for Vidalia, Torbutton, and Torcheck. However, Pootle only
en/volunteer.wml  808) translates strings that are in the "po" format, and our website uses wml
en/volunteer.wml  809) files. This project is about finding a way to convert our wml files into po
en/volunteer.wml  810) strings and back, so they can be handled by Pootle.
en/volunteer.wml  811) </li>
en/volunteer.wml  812) 

en/volunteer.wml  813) <li>
en/volunteer.wml  814) <b>New Thandy Features</b>
en/volunteer.wml  815) <br />
en/volunteer.wml  816) Priority: <i>Medium</i>
en/volunteer.wml  817) <br />
en/volunteer.wml  818) Effort Level: <i>Medium</i>
en/volunteer.wml  819) <br />
en/volunteer.wml  820) Skill Level: <i>Medium to High</i>
en/volunteer.wml  821) <br />
en/volunteer.wml  822) Likely Mentors: <i>Martin</i>
en/volunteer.wml  823) <br />
en/volunteer.wml  824) Additional capabilities are needed for assisted updates of all the Tor

en/volunteer.wml  825) related software for Windows and other operating systems. Some of the

en/volunteer.wml  826) features to consider include:
en/volunteer.wml  827) 1) Integration of the <a
en/volunteer.wml  828) href="http://chandlerproject.org/Projects/MeTooCrypto">MeTooCrypto
en/volunteer.wml  829) Python library</a>
en/volunteer.wml  830) for authenticated HTTPS downloads. 2) Adding a level of indirection
en/volunteer.wml  831) between the timestamp signatures and the package files included in an
en/volunteer.wml  832) update. See the "Thandy attacks / suggestions" thread on or-dev.
en/volunteer.wml  833) 3) Support locale specific installation and configuration of assisted
en/volunteer.wml  834) updates based on preference, host, or user account language settings.
en/volunteer.wml  835) Familiarity with Windows codepages, unicode, and other character sets
en/volunteer.wml  836) is helpful in addition to general win32 and posix API experience and
en/volunteer.wml  837) Python proficiency.
en/volunteer.wml  838) </li>
en/volunteer.wml  839) 

en/volunteer.wml  840) <li>
en/volunteer.wml  841) <b>Intermediate Level Network Device Driver</b>
en/volunteer.wml  842) <br />
en/volunteer.wml  843) Priority: <i>Low</i>
en/volunteer.wml  844) <br />
en/volunteer.wml  845) Effort Level: <i>High</i>
en/volunteer.wml  846) <br />
en/volunteer.wml  847) Skill Level: <i>High</i>
en/volunteer.wml  848) <br />
en/volunteer.wml  849) Likely Mentors: <i>Martin</i>
en/volunteer.wml  850) <br />
en/volunteer.wml  851) The WinPCAP device driver used by Tor VM for bridged networking does
en/volunteer.wml  852) not support a number of wireless and non-Ethernet network adapters.
en/volunteer.wml  853) Implementation of a intermediate level network device driver for win32
en/volunteer.wml  854) and 64bit would provide a way to intercept and route traffic over such
en/volunteer.wml  855) networks. This project will require knowledge of and experience with
en/volunteer.wml  856) Windows kernel device driver development and testing. Familiarity with
en/volunteer.wml  857) Winsock and Qemu would also be helpful.
en/volunteer.wml  858) </li>
en/volunteer.wml  859) 

en/volunteer.wml  860) <li>
en/volunteer.wml  861) <b>Tor Browser Bundle for Linux/Mac OS X</b>
en/volunteer.wml  862) <br />
en/volunteer.wml  863) Priority: <i>High</i>
en/volunteer.wml  864) <br />
en/volunteer.wml  865) Effort Level: <i>High</i>
en/volunteer.wml  866) <br />
en/volunteer.wml  867) Skill Level: <i>Medium</i>
en/volunteer.wml  868) <br />
en/volunteer.wml  869) Likely Mentors: <i>Steven</i>
en/volunteer.wml  870) <br />
en/volunteer.wml  871) The Tor Browser bundle incorporates Tor, Firefox, and the Vidalia user
en/volunteer.wml  872) interface (and optionally Pidgin IM). Components are pre-configured to
en/volunteer.wml  873) operate in a secure way, and it has very few dependencies on the
en/volunteer.wml  874) installed operating system. It has therefore become one of the most
en/volunteer.wml  875) easy to use, and popular, ways to use Tor on Windows.
en/volunteer.wml  876) <br />
en/volunteer.wml  877) However, there is currently no comparable package for Linux and Mac OS
en/volunteer.wml  878) X, so this project would be to implement Tor Browser Bundle for these
en/volunteer.wml  879) platforms. This will involve modifications to Vidalia (C++), possibly
en/volunteer.wml  880) Firefox (C) then creating and testing the launcher on a range of
en/volunteer.wml  881) operating system versions and configurations to verify portability.
en/volunteer.wml  882) <br />
en/volunteer.wml  883) Students should be familiar with application development on one or
en/volunteer.wml  884) preferably both of Linux and Mac OS X, and be comfortable with C/C++
en/volunteer.wml  885) and shell scripting.
en/volunteer.wml  886) </li>
en/volunteer.wml  887) 
en/volunteer.wml  888) <li>
en/volunteer.wml  889) <b>Simulator for slow Internet connections</b>
en/volunteer.wml  890) <br />
en/volunteer.wml  891) Priority: <i>Medium</i>
en/volunteer.wml  892) <br />
en/volunteer.wml  893) Effort Level: <i>Medium</i>
en/volunteer.wml  894) <br />
en/volunteer.wml  895) Skill Level: <i>Medium</i>
en/volunteer.wml  896) <br />
en/volunteer.wml  897) Likely Mentors: <i>Steven</i>
en/volunteer.wml  898) <br />
en/volunteer.wml  899) Many users of Tor have poor-quality Internet connections, giving low
en/volunteer.wml  900) bandwidth, high latency, and high packet loss/re-ordering. User
en/volunteer.wml  901) experience is that Tor reacts badly to these conditions, but it is
en/volunteer.wml  902) difficult to improve the situation without being able to repeat the
en/volunteer.wml  903) problems in the lab.
en/volunteer.wml  904) <br />
en/volunteer.wml  905) This project would be to build a simulation environment which
en/volunteer.wml  906) replicates the poor connectivity so that the effect on Tor performance
en/volunteer.wml  907) can be measured. Other components would be a testing utility to
en/volunteer.wml  908) establish what are the properties of connections available, and to
en/volunteer.wml  909) measure the effect of performance-improving modifications to Tor.
en/volunteer.wml  910) <br />
en/volunteer.wml  911) The tools used would be up to the student, but dummynet (for FreeBSD)
en/volunteer.wml  912) and nistnet (for Linux) are two potential components on which this
en/volunteer.wml  913) project could be built. Students should be experienced with network
en/volunteer.wml  914) programming/debugging and TCP/IP, and preferably familiar with C and a
en/volunteer.wml  915) scripting language.
en/volunteer.wml  916) </li>
en/volunteer.wml  917) 

en/volunteer.wml  918) <li>
en/volunteer.wml  919) <b>Bring up new ideas!</b>
en/volunteer.wml  920) <br />
en/volunteer.wml  921) Don't like any of these? Look at the <a

en/volunteer.wml  922) href="<svnsandbox>doc/roadmaps/2008-12-19-roadmap-full.pdf">Tor development

en/volunteer.wml  923) roadmap</a> for more ideas.

en/volunteer.wml  924) Some of the <a href="<svnsandbox>doc/spec/proposals/">current proposals</a>
en/volunteer.wml  925) might also be short on developers.

en/volunteer.wml  926) </li>
en/volunteer.wml  927) 

en/volunteer.wml  928) </ol>
en/volunteer.wml  929) 

en/volunteer.wml  930) <a id="OtherCoding"></a>
en/volunteer.wml  931) <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>

volunteer.html    932) <ol>

en/volunteer.wml  933) <li>Tor relays don't work well on Windows XP. On

en/volunteer.wml  934) Windows, Tor uses the standard <tt>select()</tt> system

en/volunteer.wml  935) call, which uses space in the non-page pool. This means

en/volunteer.wml  936) that a medium sized Tor relay will empty the non-page pool, <a

en/volunteer.wml  937) href="https://wiki.torproject.org/noreply/TheOnionRouter/WindowsBufferProblems">causing

en/volunteer.wml  938) havoc and system crashes</a>. We should probably be using overlapped IO

en/volunteer.wml  939) instead. One solution would be to teach <a
en/volunteer.wml  940) href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
en/volunteer.wml  941) overlapped IO rather than select() on Windows, and then adapt Tor to

en/volunteer.wml  942) the new libevent interface. Christian King made a

en/volunteer.wml  943) <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good

en/volunteer.wml  944) start</a> on this in the summer of 2007.</li>

en/volunteer.wml  945) 

en/volunteer.wml  946) <li>We need to actually start building our <a href="<page
en/volunteer.wml  947) documentation>#DesignDoc">blocking-resistance design</a>. This involves

en/volunteer.wml  948) fleshing out the design, modifying many different pieces of Tor, adapting
en/volunteer.wml  949) <a href="http://vidalia-project.net/">Vidalia</a> so it supports the
en/volunteer.wml  950) new features, and planning for deployment.</li>

en/volunteer.wml  951) 

en/volunteer.wml  952) <li>We need a flexible simulator framework for studying end-to-end
en/volunteer.wml  953) traffic confirmation attacks. Many researchers have whipped up ad hoc
en/volunteer.wml  954) simulators to support their intuition either that the attacks work
en/volunteer.wml  955) really well or that some defense works great. Can we build a simulator
en/volunteer.wml  956) that's clearly documented and open enough that everybody knows it's
en/volunteer.wml  957) giving a reasonable answer? This will spur a lot of new research.
en/volunteer.wml  958) See the entry <a href="#Research">below</a> on confirmation attacks for
en/volunteer.wml  959) details on the research side of this task &mdash; who knows, when it's
en/volunteer.wml  960) done maybe you can help write a paper or three also.</li>

en/volunteer.wml  961) 

en/volunteer.wml  962) <li>Tor 0.1.1.x and later include support for hardware crypto accelerators

en/volunteer.wml  963) 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  964) 

volunteer.html    965) <li>Perform a security analysis of Tor with <a
volunteer.html    966) href="http://en.wikipedia.org/wiki/Fuzz_testing">"fuzz"</a>. Determine

en/volunteer.wml  967) if there are good fuzzing libraries out there for what we want. Win fame by

volunteer.html    968) getting credit when we put out a new release because of you!</li>

en/volunteer.wml  969) 

volunteer.html    970) <li>Tor uses TCP for transport and TLS for link
volunteer.html    971) encryption. This is nice and simple, but it means all cells
volunteer.html    972) on a link are delayed when a single packet gets dropped, and
volunteer.html    973) it means we can only reasonably support TCP streams. We have a <a

en/volunteer.wml  974) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#TransportIPnotTCP">list

en/volunteer.wml  975) of reasons why we haven't shifted to UDP transport</a>, but it would
en/volunteer.wml  976) be great to see that list get shorter. We also have a proposed <a

en/volunteer.wml  977) href="<svnsandbox>doc/spec/proposals/100-tor-spec-udp.txt">specification
en/volunteer.wml  978) for Tor and

en/volunteer.wml  979) UDP</a> &mdash; please let us know what's wrong with it.</li>

en/volunteer.wml  980) 

volunteer.html    981) <li>We're not that far from having IPv6 support for destination addresses
volunteer.html    982) (at exit nodes). If you care strongly about IPv6, that's probably the
volunteer.html    983) first place to start.</li>

en/volunteer.wml  984) 
en/volunteer.wml  985) <li>We need a way to generate the website diagrams (for example, the "How
en/volunteer.wml  986) Tor Works" pictures on the <a href="<page overview>">overview page</a>
en/volunteer.wml  987) from source, so we can translate them as UTF-8 text rather than edit
en/volunteer.wml  988) them by hand with Gimp. We might want to
en/volunteer.wml  989) integrate this as an wml file so translations are easy and images are
en/volunteer.wml  990) generated in multiple languages whenever we build the website.</li>
en/volunteer.wml  991) 
en/volunteer.wml  992) <li>How can we make the <a
en/volunteer.wml  993) href="http://anonymityanywhere.com/incognito/">Incognito LiveCD</a>
en/volunteer.wml  994) easier to maintain, improve, and document?</li>

volunteer.html    995) </ol>
volunteer.html    996) 

en/volunteer.wml  997) <a id="Research"></a>
en/volunteer.wml  998) <h2><a class="anchor" href="#Research">Research</a></h2>

volunteer.html    999) <ol>

volunteer.html   1000) <li>The "website fingerprinting attack": make a list of a few
volunteer.html   1001) hundred popular websites, download their pages, and make a set of
volunteer.html   1002) "signatures" for each site. Then observe a Tor client's traffic. As
volunteer.html   1003) you watch him receive data, you quickly approach a guess about which
volunteer.html   1004) (if any) of those sites he is visiting. First, how effective is
volunteer.html   1005) this attack on the deployed Tor codebase? Then start exploring
volunteer.html   1006) defenses: for example, we could change Tor's cell size from 512
volunteer.html   1007) bytes to 1024 bytes, we could employ padding techniques like <a
volunteer.html   1008) href="http://freehaven.net/anonbib/#timing-fc2004">defensive dropping</a>,
volunteer.html   1009) or we could add traffic delays. How much of an impact do these have,
volunteer.html   1010) and how much usability impact (using some suitable metric) is there from
volunteer.html   1011) a successful defense in each case?</li>

volunteer.html   1012) <li>The "end-to-end traffic confirmation attack":
volunteer.html   1013) by watching traffic at Alice and at Bob, we can <a
volunteer.html   1014) href="http://freehaven.net/anonbib/#danezis:pet2004">compare
volunteer.html   1015) traffic signatures and become convinced that we're watching the same
volunteer.html   1016) stream</a>. So far Tor accepts this as a fact of life and assumes this
volunteer.html   1017) attack is trivial in all cases. First of all, is that actually true? How
volunteer.html   1018) much traffic of what sort of distribution is needed before the adversary
volunteer.html   1019) is confident he has won? Are there scenarios (e.g. not transmitting much)
volunteer.html   1020) that slow down the attack? Do some traffic padding or traffic shaping
volunteer.html   1021) schemes work better than others?</li>

en/volunteer.wml 1022) <li>A related question is: Does running a relay/bridge provide additional
en/volunteer.wml 1023) protection against these timing attacks? Can an external adversary that can't

en/volunteer.wml 1024) see inside TLS links still recognize individual streams reliably?

en/volunteer.wml 1025) Does the amount of traffic carried degrade this ability any? What if the
en/volunteer.wml 1026) client-relay deliberately delayed upstream relayed traffic to create a queue
en/volunteer.wml 1027) that could be used to mimic timings of client downstream traffic to make it
en/volunteer.wml 1028) look like it was also relayed? This same queue could also be used for masking
en/volunteer.wml 1029) timings in client upstream traffic with the techniques from <a
en/volunteer.wml 1030) href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
en/volunteer.wml 1031) but without the need for additional traffic. Would such an interleaving of
en/volunteer.wml 1032) client upstream traffic obscure timings for external adversaries? Would the
en/volunteer.wml 1033) strategies need to be adjusted for asymmetric links? For example, on
en/volunteer.wml 1034) asymmetric links, is it actually possible to differentiate client traffic from
en/volunteer.wml 1035) natural bursts due to their asymmetric capacity? Or is it easier than
en/volunteer.wml 1036) symmetric links for some other reason?</li>

en/volunteer.wml 1037) <li>Repeat Murdoch and Danezis's <a
en/volunteer.wml 1038) href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
en/volunteer.wml 1039) Oakland 05</a> on the current Tor network. See if you can learn why it
en/volunteer.wml 1040) works well on some nodes and not well on others. (My theory is that the
en/volunteer.wml 1041) fast nodes with spare capacity resist the attack better.) If that's true,
en/volunteer.wml 1042) then experiment with the RelayBandwidthRate and RelayBandwidthBurst
en/volunteer.wml 1043) options to run a relay that is used as a client while relaying the
en/volunteer.wml 1044) attacker's traffic: as we crank down the RelayBandwidthRate, does the
en/volunteer.wml 1045) attack get harder? What's the right ratio of RelayBandwidthRate to
en/volunteer.wml 1046) actually capacity? Or is it a ratio at all? While we're at it, does a
en/volunteer.wml 1047) much larger set of candidate relays increase the false positive rate
en/volunteer.wml 1048) or other complexity for the attack? (The Tor network is now almost two
en/volunteer.wml 1049) orders of magnitude larger than it was when they wrote their paper.) Be
en/volunteer.wml 1050) sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
en/volunteer.wml 1051) Clog the Queue</a> too.</li>

volunteer.html   1052) <li>The "routing zones attack": most of the literature thinks of
volunteer.html   1053) the network path between Alice and her entry node (and between the
volunteer.html   1054) exit node and Bob) as a single link on some graph. In practice,
volunteer.html   1055) though, the path traverses many autonomous systems (ASes), and <a
volunteer.html   1056) href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
volunteer.html   1057) that the same AS appears on both the entry path and the exit path</a>.
volunteer.html   1058) Unfortunately, to accurately predict whether a given Alice, entry,
volunteer.html   1059) exit, Bob quad will be dangerous, we need to download an entire Internet
volunteer.html   1060) routing zone and perform expensive operations on it. Are there practical
volunteer.html   1061) approximations, such as avoiding IP addresses in the same /8 network?</li>

en/volunteer.wml 1062) <li>Other research questions regarding geographic diversity consider
en/volunteer.wml 1063) the tradeoff between choosing an efficient circuit and choosing a random

en/volunteer.wml 1064) circuit. Look at Stephen Rollyson's <a

en/volunteer.wml 1065) href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
en/volunteer.wml 1066) paper</a> on how to discard particularly slow choices without hurting

en/volunteer.wml 1067) anonymity "too much". This line of reasoning needs more work and more
en/volunteer.wml 1068) thinking, but it looks very promising.</li>

en/volunteer.wml 1069) <li>Tor doesn't work very well when relays have asymmetric bandwidth

volunteer.html   1070) (e.g. cable or DSL). Because Tor has separate TCP connections between
volunteer.html   1071) each hop, if the incoming bytes are arriving just fine and the outgoing
volunteer.html   1072) bytes are all getting dropped on the floor, the TCP push-back mechanisms
volunteer.html   1073) don't really transmit this information back to the incoming streams.
volunteer.html   1074) Perhaps Tor should detect when it's dropping a lot of outgoing packets,
volunteer.html   1075) and rate-limit incoming streams to regulate this itself? I can imagine
volunteer.html   1076) a build-up and drop-off scheme where we pick a conservative rate-limit,
volunteer.html   1077) slowly increase it until we get lost packets, back off, repeat. We
volunteer.html   1078) need somebody who's good with networks to simulate this and help design
volunteer.html   1079) solutions; and/or we need to understand the extent of the performance
volunteer.html   1080) degradation, and use this as motivation to reconsider UDP transport.</li>
volunteer.html   1081) <li>A related topic is congestion control. Is our
volunteer.html   1082) current design sufficient once we have heavy use? Maybe
volunteer.html   1083) we should experiment with variable-sized windows rather
volunteer.html   1084) than fixed-size windows? That seemed to go well in an <a
volunteer.html   1085) href="http://www.psc.edu/networking/projects/hpn-ssh/theory.php">ssh
volunteer.html   1086) throughput experiment</a>. We'll need to measure and tweak, and maybe
volunteer.html   1087) overhaul if the results are good.</li>

en/volunteer.wml 1088) <li>Our censorship-resistance goals include preventing
en/volunteer.wml 1089) an attacker who's looking at Tor traffic on the wire from <a

en/volunteer.wml 1090) href="<svnsandbox>doc/design-paper/blocking.html#sec:network-fingerprint">distinguishing

en/volunteer.wml 1091) it from normal SSL traffic</a>. Obviously we can't achieve perfect
en/volunteer.wml 1092) steganography and still remain usable, but for a first step we'd like to
en/volunteer.wml 1093) block any attacks that can win by observing only a few packets. One of
en/volunteer.wml 1094) the remaining attacks we haven't examined much is that Tor cells are 512
en/volunteer.wml 1095) bytes, so the traffic on the wire may well be a multiple of 512 bytes.
en/volunteer.wml 1096) How much does the batching and overhead in TLS records blur this on the
en/volunteer.wml 1097) wire? Do different buffer flushing strategies in Tor affect this? Could
en/volunteer.wml 1098) a bit of padding help a lot, or is this an attack we must accept?</li>

volunteer.html   1099) <li>Tor circuits are built one hop at a time, so in theory we have the
volunteer.html   1100) ability to make some streams exit from the second hop, some from the
volunteer.html   1101) third, and so on. This seems nice because it breaks up the set of exiting

en/volunteer.wml 1102) streams that a given relay can see. But if we want each stream to be safe,

volunteer.html   1103) the "shortest" path should be at least 3 hops long by our current logic, so
volunteer.html   1104) the rest will be even longer. We need to examine this performance / security
volunteer.html   1105) tradeoff.</li>

en/volunteer.wml 1106) <li>It's not that hard to DoS Tor relays or directory authorities. Are client

volunteer.html   1107) puzzles the right answer? What other practical approaches are there? Bonus
volunteer.html   1108) if they're backward-compatible with the current Tor protocol.</li>

en/volunteer.wml 1109) <li>Programs like <a

en/volunteer.wml 1110) href="<page torbutton/index>">Torbutton</a> aim to hide

en/volunteer.wml 1111) your browser's UserAgent string by replacing it with a uniform answer for
en/volunteer.wml 1112) every Tor user. That way the attacker can't splinter Tor's anonymity set
en/volunteer.wml 1113) by looking at that header. It tries to pick a string that is commonly used
en/volunteer.wml 1114) by non-Tor users too, so it doesn't stand out. Question one: how badly
en/volunteer.wml 1115) do we hurt ourselves by periodically updating the version of Firefox
en/volunteer.wml 1116) that Torbutton claims to be? If we update it too often, we splinter the
en/volunteer.wml 1117) anonymity sets ourselves. If we don't update it often enough, then all the
en/volunteer.wml 1118) Tor users stand out because they claim to be running a quite old version
en/volunteer.wml 1119) of Firefox. The answer here probably depends on the Firefox versions seen
en/volunteer.wml 1120) in the wild. Question two: periodically people ask us to cycle through N
en/volunteer.wml 1121) UserAgent strings rather than stick with one. Does this approach help,
en/volunteer.wml 1122) hurt, or not matter? Consider: cookies and recognizing Torbutton users
en/volunteer.wml 1123) by their rotating UserAgents; malicious websites who only attack certain
en/volunteer.wml 1124) browsers; and whether the answers to question one impact this answer.
en/volunteer.wml 1125) </li>

en/volunteer.wml 1126) <li>Right now Tor clients are willing to reuse a given circuit for ten
en/volunteer.wml 1127) minutes after it's first used. The goal is to avoid loading down the
en/volunteer.wml 1128) network with too many circuit extend operations, yet to also avoid having
en/volunteer.wml 1129) clients use the same circuit for so long that the exit node can build a
en/volunteer.wml 1130) useful pseudonymous profile of them. Alas, ten minutes is probably way
en/volunteer.wml 1131) too long, especially if connections from multiple protocols (e.g. IM and
en/volunteer.wml 1132) web browsing) are put on the same circuit. If we keep fixed the overall
en/volunteer.wml 1133) number of circuit extends that the network needs to do, are there more
en/volunteer.wml 1134) efficient and/or safer ways for clients to allocate streams to circuits,
en/volunteer.wml 1135) or for clients to build preemptive circuits? Perhaps this research item
en/volunteer.wml 1136) needs to start with gathering some traces of what connections typical
en/volunteer.wml 1137) clients try to launch, so you have something realistic to try to optimize.
en/volunteer.wml 1138) </li>
en/volunteer.wml 1139) <li>How many bridge relays do you need to know to maintain
en/volunteer.wml 1140) reachability? We should measure the churn in our bridges. If there is
en/volunteer.wml 1141) lots of churn, are there ways to keep bridge users more likely to stay
en/volunteer.wml 1142) connected?
en/volunteer.wml 1143) </li>

volunteer.html   1144) </ol>
volunteer.html   1145) 

en/volunteer.wml 1146) <p>

en/volunteer.wml 1147) <a href="<page contact>">Let us know</a> if you've made progress on any
en/volunteer.wml 1148) of these!

en/volunteer.wml 1149) </p>

volunteer.html   1150) 

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volunteer.html   1152) 

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