@@ -46,7 +46,7 @@

     Individuals use Tor to keep websites from tracking them and their family

     members, or to connect to news sites, instant messaging services, or the

     like when these are blocked by their local Internet providers.  Tor's <a

-    href="<page docs/hidden-services>">onion services</a>

+    href="<page docs/onion-services>">onion services</a>

     let users publish web sites and other services without needing to reveal

     the location of the site. Individuals also use Tor for socially sensitive

     communication: chat rooms and web forums for rape and abuse survivors,

@@ -46,7 +46,7 @@

     Individuals use Tor to keep websites from tracking them and their family

     members, or to connect to news sites, instant messaging services, or the

     like when these are blocked by their local Internet providers.  Tor's <a

-    href="<page docs/hidden-services>">hidden services</a>

+    href="<page docs/hidden-services>">onion services</a>

     let users publish web sites and other services without needing to reveal

     the location of the site. Individuals also use Tor for socially sensitive

     communication: chat rooms and web forums for rape and abuse survivors,

@@ -29,13 +29,17 @@

     <h3><a class="anchor" href="#overview">Overview</a></h3>

     <p>

-    Tor is a network of virtual tunnels that allows people and groups to

-    improve their privacy and security on the Internet.  It also enables

-    software developers to create new communication tools

-    with built-in privacy features.  Tor provides the foundation for

-    a range of applications that allow organizations and individuals

-    to share information over public networks without compromising their

-    privacy.

+    The Tor network is a group of <a href="<page

+    getinvolved/volunteer>">volunteer</a>-operated servers that allows people

+    to improve their privacy and security on the Internet. Tor's users employ

+    this network by connecting through a series of virtual tunnels rather than

+    making a direct connection, thus allowing both organizations and

+    individuals to share information over public networks without compromising

+    their privacy. Along the same line, Tor is an effective censorship

+    circumvention tool, allowing its users to reach otherwise blocked

+    destinations or content.  Tor can also be used as a building block for

+    software developers to create new communication tools with built-in privacy

+    features.

     </p>

     <p>

@@ -17,7 +17,6 @@

         <li><a href="<page about/overview>#overview">Overview</a></li>

         <li><a href="<page about/overview>#whyweneedtor">Why we need Tor</a></li>

         <li><a href="<page about/overview>#thesolution">The Solution</a></li>

-        <li><a href="<page about/overview>#hiddenservices">Hidden services</a></li>

         <li><a href="<page about/overview>#stayinganonymous">Staying anonymous</a></li>

         <li><a href="<page about/overview>#thefutureoftor">The future of Tor</a></li>

       </ul>

@@ -182,24 +181,6 @@

     <p><img alt="Tor circuit step three" src="$(IMGROOT)/htw3.png"></p>

-

-    <a name="hiddenservices"></a>

-    <h3><a class="anchor" href="#hiddenservices">Hidden services</a></h3>

-

-    <p>

-    Tor also makes it possible for users to hide their locations while

-    offering various kinds of services, such as web publishing or an instant

-    messaging server.  Using Tor "rendezvous points," other Tor users can

-    connect to these hidden services, each without knowing the other's

-    network identity.  This hidden service functionality could allow Tor

-    users to set up a website where people publish material without worrying

-    about censorship.  Nobody would be able to determine who was offering

-    the site, and nobody who offered the site would know who was posting to it.

-    Learn more about <a href="<page docs/tor-hidden-service>">configuring

-    hidden services</a> and how the <a href="<page docs/hidden-services>">hidden

-    service protocol</a> works.

-    </p>

-

     <a name="stayinganonymous"></a>

     <h3><a class="anchor" href="#stayinganonymous">Staying anonymous</a></h3>

@@ -14,7 +14,6 @@

     <div class="sidebar-left">

       <h3>Topics</h3>

       <ul>

-        <li><a href="<page about/overview>#inception">Inception</a></li>

         <li><a href="<page about/overview>#overview">Overview</a></li>

         <li><a href="<page about/overview>#whyweneedtor">Why we need Tor</a></li>

         <li><a href="<page about/overview>#thesolution">The Solution</a></li>

@@ -27,19 +26,6 @@

     <hr>

-    <a name="inception"></a>

-    <h3><a class="anchor" href="#inception">Inception</a></h3>

-

-    <p>

-    Tor was originally designed, implemented, and deployed as a

-    third-generation <a href="http://www.onion-router.net/">onion routing

-    project of the U.S. Naval Research Laboratory</a>.  It was originally

-    developed with the U.S. Navy in mind, for the primary purpose of

-    protecting government communications.  Today, it is used every day

-    for a wide variety of purposes by normal people, the military,

-    journalists, law enforcement officers, activists, and many

-    others. </p>

-

     <a name="overview"></a>

     <h3><a class="anchor" href="#overview">Overview</a></h3>

@@ -221,8 +221,8 @@

     Tor can't solve all anonymity problems.  It focuses only on

     protecting the transport of data.  You need to use protocol-specific

     support software if you don't want the sites you visit to see your

-    identifying information. For example, you can use the <a href="<page

-    projects/torbrowser>">Tor Browser Bundle</a>

+    identifying information. For example, you can use <a href="<page

+    projects/torbrowser>">Tor Browser</a>

     while browsing the web to withhold some information about your computer's

     configuration.

     </p>

@@ -221,7 +221,8 @@

     Tor can't solve all anonymity problems.  It focuses only on

     protecting the transport of data.  You need to use protocol-specific

     support software if you don't want the sites you visit to see your

-    identifying information. For example, you can use Tor Browser Bundle

+    identifying information. For example, you can use the <a href="<page

+    projects/torbrowser>">Tor Browser Bundle</a>

     while browsing the web to withhold some information about your computer's

     configuration.

     </p>

@@ -221,7 +221,7 @@

     Tor can't solve all anonymity problems.  It focuses only on

     protecting the transport of data.  You need to use protocol-specific

     support software if you don't want the sites you visit to see your

-    identifying information. For example, you can use Torbutton

+    identifying information. For example, you can use Tor Browser Bundle

     while browsing the web to withhold some information about your computer's

     configuration.

     </p>

@@ -24,7 +24,7 @@

       </ul>

     </div>

     <!-- END SIDEBAR -->

-    

+

     <hr>

     <a name="inception"></a>

@@ -39,7 +39,7 @@

     for a wide variety of purposes by normal people, the military,

     journalists, law enforcement officers, activists, and many

     others. </p>

-    

+

     <a name="overview"></a>

     <h3><a class="anchor" href="#overview">Overview</a></h3>

@@ -52,7 +52,7 @@

     to share information over public networks without compromising their

     privacy.

     </p>

-    

+

     <p>

     Individuals use Tor to keep websites from tracking them and their family

     members, or to connect to news sites, instant messaging services, or the

@@ -63,7 +63,7 @@

     communication: chat rooms and web forums for rape and abuse survivors,

     or people with illnesses.

     </p>

-    

+

     <p>

     Journalists use Tor to communicate more safely with whistleblowers and

     dissidents. Non-governmental organizations (NGOs) use Tor to allow their

@@ -71,7 +71,7 @@

     country, without notifying everybody nearby that they're working with

     that organization.

     </p>

-    

+

     <p>

     Groups such as Indymedia recommend Tor for safeguarding their members'

     online privacy and security. Activist groups like the Electronic Frontier

@@ -84,7 +84,7 @@

     consulting job-hunting websites? Which research divisions are communicating

     with the company's patent lawyers?

     </p>

-    

+

     <p>

     A branch of the U.S. Navy uses Tor for open source intelligence

     gathering, and one of its teams used Tor while deployed in the Middle

@@ -92,7 +92,7 @@

     web sites without leaving government IP addresses in their web logs,

     and for security during sting operations.

     </p>

-    

+

     <p>

     The variety of people who use Tor is actually <a

     href="http://freehaven.net/doc/fc03/econymics.pdf">part of what makes

@@ -101,10 +101,10 @@

     so the more populous and diverse the user base for Tor is, the more your

     anonymity will be protected.

     </p>

-    

+

     <a name="whyweneedtor"></a>

     <h3><a class="anchor" href="#whyweneedtor">Why we need Tor</a></h3>

-    

+

     <p>

     Using Tor protects you against a common form of Internet surveillance

     known as "traffic analysis."  Traffic analysis can be used to infer

@@ -119,7 +119,7 @@

     affiliation to anyone observing the network, even if the connection

     is encrypted.

     </p>

-    

+

     <p>

     How does traffic analysis work?  Internet data packets have two parts:

     a data payload and a header used for routing.  The data payload is

@@ -129,7 +129,7 @@

     possibly, what you're saying.  That's because it focuses on the header,

     which discloses source, destination, size, timing, and so on.

     </p>

-    

+

     <p>

     A basic problem for the privacy minded is that the recipient of your

     communications can see that you sent it by looking at headers.  So can

@@ -138,7 +138,7 @@

     analysis might involve sitting somewhere between sender and recipient on

     the network, looking at headers.

     </p>

-    

+

     <p>

     But there are also more powerful kinds of traffic analysis.  Some

     attackers spy on multiple parts of the Internet and use sophisticated

@@ -147,11 +147,11 @@

     these attackers, since it only hides the content of Internet traffic, not

     the headers.

     </p>

-    

+

     <a name="thesolution"></a>

     <h3><a class="anchor" href="#thesolution">The solution: a distributed, anonymous network</a></h3>

     <img src="$(IMGROOT)/htw1.png" alt="How Tor works">

-    

+

     <p>

     Tor helps to reduce the risks of both simple and sophisticated traffic

     analysis by distributing your transactions over several places on the

@@ -163,7 +163,7 @@

     through several relays that cover your tracks so no observer at any

     single point can tell where the data came from or where it's going.

     </p>

-    

+

     <p>

     To create a private network pathway with Tor, the user's software or

     client incrementally builds a circuit of encrypted connections through

@@ -174,9 +174,9 @@

     separate set of encryption keys for each hop along the circuit to ensure

     that each hop can't trace these connections as they pass through.

     </p>

-    

+

     <p><img alt="Tor circuit step two"  src="$(IMGROOT)/htw2.png"></p>

-    

+

     <p>

     Once a circuit has been established, many kinds of data can be exchanged

     and several different sorts of software applications can be deployed

@@ -186,20 +186,20 @@

     only works for TCP streams and can be used by any application with SOCKS

     support.

     </p>

-    

+

     <p>

     For efficiency, the Tor software uses the same circuit for connections

     that happen within the same ten minutes or so.  Later requests are given a

     new circuit, to keep people from linking your earlier actions to the new

     ones.

     </p>

-    

+

     <p><img alt="Tor circuit step three" src="$(IMGROOT)/htw3.png"></p>

-    

-    

+

+

     <a name="hiddenservices"></a>

     <h3><a class="anchor" href="#hiddenservices">Hidden services</a></h3>

-    

+

     <p>

     Tor also makes it possible for users to hide their locations while

     offering various kinds of services, such as web publishing or an instant

@@ -213,10 +213,10 @@

     hidden services</a> and how the <a href="<page docs/hidden-services>">hidden

     service protocol</a> works.

     </p>

-    

+

     <a name="stayinganonymous"></a>

     <h3><a class="anchor" href="#stayinganonymous">Staying anonymous</a></h3>

-    

+

     <p>

     Tor can't solve all anonymity problems.  It focuses only on

     protecting the transport of data.  You need to use protocol-specific

@@ -225,7 +225,7 @@

     while browsing the web to withhold some information about your computer's

     configuration.

     </p>

-    

+

     <p>

     Also, to protect your anonymity, be smart.  Don't provide your name

     or other revealing information in web forms.  Be aware that, like all

@@ -235,10 +235,10 @@

     arriving at your chosen destination, he can use statistical analysis to

     discover that they are part of the same circuit.

     </p>

-    

+

     <a name="thefutureoftor"></a>

     <h3><a class="anchor" href="#thefutureoftor">The future of Tor</a></h3>

-    

+

     <p>

     Providing a usable anonymizing network on the Internet today is an

     ongoing challenge. We want software that meets users' needs. We also

@@ -252,7 +252,7 @@

     or <a href="<page getinvolved/volunteer>">volunteering</a> as a

     <a href="<page docs/documentation>#Developers">developer</a>.

     </p>

-    

+

     <p>

     Ongoing trends in law, policy, and technology threaten anonymity as never

     before, undermining our ability to speak and read freely online. These

@@ -262,7 +262,7 @@

     provides additional diversity, enhancing Tor's ability to put control

     over your security and privacy back into your hands.

     </p>

-    

+

   </div>

   <!-- END MAINCOL -->

   <div id = "sidecol">

@@ -272,4 +272,4 @@

   <!-- END SIDECOL -->

 </div>

 <!-- END CONTENT -->

-#include <foot.wmi> 

+#include <foot.wmi>

@@ -221,9 +221,9 @@

     Tor can't solve all anonymity problems.  It focuses only on

     protecting the transport of data.  You need to use protocol-specific

     support software if you don't want the sites you visit to see your

-    identifying information. For example, you can use web proxies such as

-    Privoxy while web browsing to block cookies and withhold information

-    about your browser type.

+    identifying information. For example, you can use Torbutton

+    while browsing the web to withhold some information about your computer's

+    configuration.

     </p>

     <p>

@@ -41,7 +41,7 @@

     others. </p>

     <a name="overview"></a>

-    <h3><a class="anchor" href="#overview">Tor: Overview</a></h3>

+    <h3><a class="anchor" href="#overview">Overview</a></h3>

     <p>

     Tor is a network of virtual tunnels that allows people and groups to

@@ -9,14 +9,13 @@

     <a href="<page about/overview>">About &raquo; </a>

   </div>

   <div id="maincol">

-    <a name="overview"></a>

-    <h2><a class="anchor" href="#overview">Tor: Overview</a></h2>

+    <h2>Tor: Overview</h2>

     <!-- BEGIN SIDEBAR -->

     <div class="sidebar-left">

       <h3>Topics</h3>

       <ul>

-        <li><a href="<page about/overview>#overview">Overview</a></li>

         <li><a href="<page about/overview>#inception">Inception</a></li>

+        <li><a href="<page about/overview>#overview">Overview</a></li>

         <li><a href="<page about/overview>#whyweneedtor">Why we need Tor</a></li>

         <li><a href="<page about/overview>#thesolution">The Solution</a></li>

         <li><a href="<page about/overview>#hiddenservices">Hidden services</a></li>

@@ -41,6 +40,9 @@

     journalists, law enforcement officers, activists, and many

     others. </p>

+    <a name="overview"></a>

+    <h3><a class="anchor" href="#overview">Tor: Overview</a></h3>

+

     <p>

     Tor is a network of virtual tunnels that allows people and groups to

     improve their privacy and security on the Internet.  It also enables

@@ -16,6 +16,7 @@

       <h3>Topics</h3>

       <ul>

         <li><a href="<page about/overview>#overview">Overview</a></li>

+        <li><a href="<page about/overview>#inception">Inception</a></li>

         <li><a href="<page about/overview>#whyweneedtor">Why we need Tor</a></li>

         <li><a href="<page about/overview>#thesolution">The Solution</a></li>

         <li><a href="<page about/overview>#hiddenservices">Hidden services</a></li>

@@ -26,6 +27,19 @@

     <!-- END SIDEBAR -->

     <hr>

+

+    <a name="inception"></a>

+    <h3><a class="anchor" href="#inception">Inception</a></h3>

+

+    <p>

+    Tor was originally designed, implemented, and deployed as a

+    third-generation <a href="http://www.onion-router.net/">onion routing

+    project of the U.S. Naval Research Laboratory</a>.  It was originally

+    developed with the U.S. Navy in mind, for the primary purpose of

+    protecting government communications.  Today, it is used every day

+    for a wide variety of purposes by normal people, the military,

+    journalists, law enforcement officers, activists, and many

+    others. </p>

     <p>

     Tor is a network of virtual tunnels that allows people and groups to

@@ -148,8 +148,6 @@

     single point can tell where the data came from or where it's going.

     </p>

-    <p><img alt="Tor circuit step one" src="$(IMGROOT)/htw1.png"></p>

-    

     <p>

     To create a private network pathway with Tor, the user's software or

     client incrementally builds a circuit of encrypted connections through

@@ -1,5 +1,5 @@

 ## translation metadata

-# Revision: $Revision: 22308 $

+# Revision: $Revision$

 # Translation-Priority: 2-medium

 #include "head.wmi" TITLE="Tor Project: Overview" CHARSET="UTF-8"

@@ -25,7 +25,7 @@

     </div>

     <!-- END SIDEBAR -->

-    <hr />

+    <hr>

     <p>

     Tor is a network of virtual tunnels that allows people and groups to

@@ -134,7 +134,7 @@

     <a name="thesolution"></a>

     <h3><a class="anchor" href="#thesolution">The solution: a distributed, anonymous network</a></h3>

-    <img src="$(IMGROOT)/htw1.png" alt="How Tor works" />

+    <img src="$(IMGROOT)/htw1.png" alt="How Tor works">

     <p>

     Tor helps to reduce the risks of both simple and sophisticated traffic

@@ -148,7 +148,7 @@

     single point can tell where the data came from or where it's going.

     </p>

-    <p><img alt="Tor circuit step one" src="$(IMGROOT)/htw1.png" /></p>

+    <p><img alt="Tor circuit step one" src="$(IMGROOT)/htw1.png"></p>

     <p>

     To create a private network pathway with Tor, the user's software or

@@ -161,7 +161,7 @@

     that each hop can't trace these connections as they pass through.

     </p>

-    <p><img alt="Tor circuit step two"  src="$(IMGROOT)/htw2.png" /></p>

+    <p><img alt="Tor circuit step two"  src="$(IMGROOT)/htw2.png"></p>

     <p>

     Once a circuit has been established, many kinds of data can be exchanged

@@ -180,7 +180,7 @@

     ones.

     </p>

-    <p><img alt="Tor circuit step three" src="$(IMGROOT)/htw3.png" /></p>

+    <p><img alt="Tor circuit step three" src="$(IMGROOT)/htw3.png"></p>

     <a name="hiddenservices"></a>

@@ -134,7 +134,7 @@

     <a name="thesolution"></a>

     <h3><a class="anchor" href="#thesolution">The solution: a distributed, anonymous network</a></h3>

-    <img src="$(IMGROOT)/htw-1.png" alt="How Tor works" />

+    <img src="$(IMGROOT)/htw1.png" alt="How Tor works" />

     <p>

     Tor helps to reduce the risks of both simple and sophisticated traffic

@@ -134,7 +134,7 @@

     <a name="thesolution"></a>

     <h3><a class="anchor" href="#thesolution">The solution: a distributed, anonymous network</a></h3>

-    <img src="images/htw-1.png" alt="How Tor works" />

+    <img src="$(IMGROOT)/htw-1.png" alt="How Tor works" />

     <p>

     Tor helps to reduce the risks of both simple and sophisticated traffic

@@ -6,8 +6,7 @@

 <div id="content" class="clearfix">

   <div id="breadcrumbs">

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

-    <a href="<page about/about>">About &raquo; </a>

-    <a href="<page about/about>">Overview</a>

+    <a href="<page about/overview>">About &raquo; </a>

   </div>

   <div id="maincol">

     <a name="overview"></a>

@@ -162,7 +161,7 @@

     that each hop can't trace these connections as they pass through.

     </p>

-    <p><img alt="Tor circuit step two" src="$(IMGROOT)/htw2.png" /></p>

+    <p><img alt="Tor circuit step two"  src="$(IMGROOT)/htw2.png" /></p>

     <p>

     Once a circuit has been established, many kinds of data can be exchanged

@@ -135,6 +135,7 @@

     <a name="thesolution"></a>

     <h3><a class="anchor" href="#thesolution">The solution: a distributed, anonymous network</a></h3>

+    <img src="images/htw-1.png" alt="How Tor works" />

     <p>

     Tor helps to reduce the risks of both simple and sophisticated traffic

@@ -5,7 +5,7 @@

 #include "head.wmi" TITLE="Tor Project: Overview" CHARSET="UTF-8"

 <div id="content" class="clearfix">

   <div id="breadcrumbs">

-    <a href="<page home>">Home &raquo; </a>

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

     <a href="<page about/about>">About &raquo; </a>

     <a href="<page about/about>">Overview</a>

   </div>

new file mode 100644

@@ -0,0 +1,261 @@

+## translation metadata

+# Revision: $Revision: 22308 $

+# Translation-Priority: 2-medium

+

+#include "head.wmi" TITLE="Tor Project: Overview" CHARSET="UTF-8"

+<div id="content" class="clearfix">

+  <div id="breadcrumbs">

+    <a href="<page home>">Home &raquo; </a>

+    <a href="<page about/about>">About &raquo; </a>

+    <a href="<page about/about>">Overview</a>

+  </div>

+  <div id="maincol">

+    <a name="overview"></a>

+    <h2><a class="anchor" href="#overview">Tor: Overview</a></h2>

+    <!-- BEGIN SIDEBAR -->

+    <div class="sidebar-left">

+      <h3>Topics</h3>

+      <ul>

+        <li><a href="<page about/overview>#overview">Overview</a></li>

+        <li><a href="<page about/overview>#whyweneedtor">Why we need Tor</a></li>

+        <li><a href="<page about/overview>#thesolution">The Solution</a></li>

+        <li><a href="<page about/overview>#hiddenservices">Hidden services</a></li>

+        <li><a href="<page about/overview>#stayinganonymous">Staying anonymous</a></li>

+        <li><a href="<page about/overview>#thefutureoftor">The future of Tor</a></li>

+      </ul>

+    </div>

+    <!-- END SIDEBAR -->

+    

+    <hr />

+    

+    <p>

+    Tor is a network of virtual tunnels that allows people and groups to

+    improve their privacy and security on the Internet.  It also enables

+    software developers to create new communication tools

+    with built-in privacy features.  Tor provides the foundation for

+    a range of applications that allow organizations and individuals

+    to share information over public networks without compromising their

+    privacy.

+    </p>

+    

+    <p>

+    Individuals use Tor to keep websites from tracking them and their family

+    members, or to connect to news sites, instant messaging services, or the

+    like when these are blocked by their local Internet providers.  Tor's <a

+    href="<page docs/hidden-services>">hidden services</a>

+    let users publish web sites and other services without needing to reveal

+    the location of the site. Individuals also use Tor for socially sensitive

+    communication: chat rooms and web forums for rape and abuse survivors,

+    or people with illnesses.

+    </p>

+    

+    <p>

+    Journalists use Tor to communicate more safely with whistleblowers and

+    dissidents. Non-governmental organizations (NGOs) use Tor to allow their

+    workers to connect to their home website while they're in a foreign

+    country, without notifying everybody nearby that they're working with

+    that organization.

+    </p>

+    

+    <p>

+    Groups such as Indymedia recommend Tor for safeguarding their members'

+    online privacy and security. Activist groups like the Electronic Frontier

+    Foundation (EFF) recommend Tor as a mechanism for

+    maintaining civil liberties online. Corporations use Tor as a safe way

+    to conduct competitive analysis, and to protect sensitive procurement

+    patterns from eavesdroppers. They also use it to replace traditional

+    VPNs, which reveal the exact amount and timing of communication. Which

+    locations have employees working late? Which locations have employees

+    consulting job-hunting websites? Which research divisions are communicating

+    with the company's patent lawyers?

+    </p>

+    

+    <p>

+    A branch of the U.S. Navy uses Tor for open source intelligence

+    gathering, and one of its teams used Tor while deployed in the Middle

+    East recently. Law enforcement uses Tor for visiting or surveilling

+    web sites without leaving government IP addresses in their web logs,

+    and for security during sting operations.

+    </p>

+    

+    <p>

+    The variety of people who use Tor is actually <a

+    href="http://freehaven.net/doc/fc03/econymics.pdf">part of what makes

+    it so secure</a>.  Tor hides you among <a href="<page about/torusers>">the

+    other users on the network</a>,

+    so the more populous and diverse the user base for Tor is, the more your

+    anonymity will be protected.

+    </p>

+    

+    <a name="whyweneedtor"></a>

+    <h3><a class="anchor" href="#whyweneedtor">Why we need Tor</a></h3>

+    

+    <p>

+    Using Tor protects you against a common form of Internet surveillance

+    known as "traffic analysis."  Traffic analysis can be used to infer

+    who is talking to whom over a public network.  Knowing the source

+    and destination of your Internet traffic allows others to track your

+    behavior and interests.  This can impact your checkbook if, for example,

+    an e-commerce site uses price discrimination based on your country or

+    institution of origin.  It can even threaten your job and physical safety

+    by revealing who and where you are. For example, if you're travelling

+    abroad and you connect to your employer's computers to check or send mail,

+    you can inadvertently reveal your national origin and professional

+    affiliation to anyone observing the network, even if the connection

+    is encrypted.

+    </p>

+    

+    <p>

+    How does traffic analysis work?  Internet data packets have two parts:

+    a data payload and a header used for routing.  The data payload is

+    whatever is being sent, whether that's an email message, a web page, or an

+    audio file.  Even if you encrypt the data payload of your communications,

+    traffic analysis still reveals a great deal about what you're doing and,

+    possibly, what you're saying.  That's because it focuses on the header,

+    which discloses source, destination, size, timing, and so on.

+    </p>

+    

+    <p>

+    A basic problem for the privacy minded is that the recipient of your

+    communications can see that you sent it by looking at headers.  So can

+    authorized intermediaries like Internet service providers, and sometimes

+    unauthorized intermediaries as well.  A very simple form of traffic

+    analysis might involve sitting somewhere between sender and recipient on

+    the network, looking at headers.

+    </p>

+    

+    <p>

+    But there are also more powerful kinds of traffic analysis.  Some

+    attackers spy on multiple parts of the Internet and use sophisticated

+    statistical techniques to track the communications patterns of many

+    different organizations and individuals.  Encryption does not help against

+    these attackers, since it only hides the content of Internet traffic, not

+    the headers.

+    </p>

+    

+    <a name="thesolution"></a>

+    <h3><a class="anchor" href="#thesolution">The solution: a distributed, anonymous network</a></h3>

+    

+    <p>

+    Tor helps to reduce the risks of both simple and sophisticated traffic

+    analysis by distributing your transactions over several places on the

+    Internet, so no single point can link you to your destination.  The idea

+    is similar to using a twisty, hard-to-follow route in order to throw off

+    somebody who is tailing you — and then periodically erasing your

+    footprints.  Instead of taking a direct route from source to

+    destination, data packets on the Tor network take a random pathway

+    through several relays that cover your tracks so no observer at any

+    single point can tell where the data came from or where it's going.

+    </p>

+    

+    <p><img alt="Tor circuit step one" src="$(IMGROOT)/htw1.png" /></p>

+    

+    <p>

+    To create a private network pathway with Tor, the user's software or

+    client incrementally builds a circuit of encrypted connections through

+    relays on the network.  The circuit is extended one hop at a time, and

+    each relay along the way knows only which relay gave it data and which

+    relay it is giving data to.  No individual relay ever knows the

+    complete path that a data packet has taken.  The client negotiates a

+    separate set of encryption keys for each hop along the circuit to ensure

+    that each hop can't trace these connections as they pass through.

+    </p>

+    

+    <p><img alt="Tor circuit step two" src="$(IMGROOT)/htw2.png" /></p>

+    

+    <p>

+    Once a circuit has been established, many kinds of data can be exchanged

+    and several different sorts of software applications can be deployed

+    over the Tor network.  Because each relay sees no more than one hop in

+    the circuit, neither an eavesdropper nor a compromised relay can use

+    traffic analysis to link the connection's source and destination.  Tor

+    only works for TCP streams and can be used by any application with SOCKS

+    support.

+    </p>

+    

+    <p>

+    For efficiency, the Tor software uses the same circuit for connections

+    that happen within the same ten minutes or so.  Later requests are given a

+    new circuit, to keep people from linking your earlier actions to the new

+    ones.

+    </p>

+    

+    <p><img alt="Tor circuit step three" src="$(IMGROOT)/htw3.png" /></p>

+    

+    

+    <a name="hiddenservices"></a>

+    <h3><a class="anchor" href="#hiddenservices">Hidden services</a></h3>

+    

+    <p>

+    Tor also makes it possible for users to hide their locations while

+    offering various kinds of services, such as web publishing or an instant

+    messaging server.  Using Tor "rendezvous points," other Tor users can

+    connect to these hidden services, each without knowing the other's

+    network identity.  This hidden service functionality could allow Tor

+    users to set up a website where people publish material without worrying

+    about censorship.  Nobody would be able to determine who was offering

+    the site, and nobody who offered the site would know who was posting to it.

+    Learn more about <a href="<page docs/tor-hidden-service>">configuring

+    hidden services</a> and how the <a href="<page docs/hidden-services>">hidden

+    service protocol</a> works.

+    </p>

+    

+    <a name="stayinganonymous"></a>

+    <h3><a class="anchor" href="#stayinganonymous">Staying anonymous</a></h3>

+    

+    <p>

+    Tor can't solve all anonymity problems.  It focuses only on

+    protecting the transport of data.  You need to use protocol-specific

+    support software if you don't want the sites you visit to see your

+    identifying information. For example, you can use web proxies such as

+    Privoxy while web browsing to block cookies and withhold information

+    about your browser type.

+    </p>

+    

+    <p>

+    Also, to protect your anonymity, be smart.  Don't provide your name

+    or other revealing information in web forms.  Be aware that, like all

+    anonymizing networks that are fast enough for web browsing, Tor does not

+    provide protection against end-to-end timing attacks: If your attacker

+    can watch the traffic coming out of your computer, and also the traffic

+    arriving at your chosen destination, he can use statistical analysis to

+    discover that they are part of the same circuit.

+    </p>

+    

+    <a name="thefutureoftor"></a>

+    <h3><a class="anchor" href="#thefutureoftor">The future of Tor</a></h3>

+    

+    <p>

+    Providing a usable anonymizing network on the Internet today is an

+    ongoing challenge. We want software that meets users' needs. We also

+    want to keep the network up and running in a way that handles as many

+    users as possible. Security and usability don't have to be at odds:

+    As Tor's usability increases, it will attract more users, which will

+    increase the possible sources and destinations of each communication,

+    thus increasing security for everyone.

+    We're making progress, but we need your help.  Please consider

+    <a href="<page docs/tor-doc-relay>">running a relay</a>

+    or <a href="<page getinvolved/volunteer>">volunteering</a> as a

+    <a href="<page docs/documentation>#Developers">developer</a>.

+    </p>

+    

+    <p>

+    Ongoing trends in law, policy, and technology threaten anonymity as never

+    before, undermining our ability to speak and read freely online. These

+    trends also undermine national security and critical infrastructure by

+    making communication among individuals, organizations, corporations,

+    and governments more vulnerable to analysis. Each new user and relay

+    provides additional diversity, enhancing Tor's ability to put control

+    over your security and privacy back into your hands.

+    </p>

+    

+  </div>

+  <!-- END MAINCOL -->

+  <div id = "sidecol">

+#include "side.wmi"

+#include "info.wmi"

+  </div>

+  <!-- END SIDECOL -->

+</div>

+<!-- END CONTENT -->

+#include <foot.wmi>