Веб обозреватель Тор, как уже упоминалось выше, вполне бесплатен и доступен для скачки хоть какому юзеру. Невзирая на наличие неких недочетов низкой скорости и невозможности использования личных данных, к примеру, почты, популярность тор браузера на российском языке чрезвычайно велика.
С его помощью можно посещать фактически любые ресурсы, заблокированные провайдером по требованию властей. Эта изюминка тор браузера для виндовс в особенности актуальна в крайнее время из-за закрытия целого ряда веб-сайтов. Не считая этого, в закрытой сети Тор существует и процветает целый мир, теневой сектор Веба, который еще именуют глубочайшей сетью. Эта часть Сети нередко употребляется для не совершенно законной деятельности, и через обыденный браузер она недосягаема.
Скачать последнюю версию тор браузер безвозмездно можно на официальной страничке проекта, которая просто находится по запросу в хоть какой поисковой системе. Установка чрезвычайно проста и ничем не различается от установки обыденного браузера. Опосля окончания установки на рабочем столе покажется иконка тор браузер на пк. При первом запуске tor browser покажется окошко с вопросцем как подключаться к сети Тор? Рекомендуется выбирать прямое подключение.
Используя этот значок, можно сделать полный перезапуск браузера и на сто процентов поменять конфигурацию сети. Для этого необходимо выбрать клавишу Поменять личность, разрешить закрыть все вкладки и перезапустить Тор. Для поиска в доменной зоне с которой соединяется тор браузер для виндовс, имеется интегрированный поисковик DuckDuckGо.
Недочет этого поисковика в том, что он отыскивает лишь в открытом Вебе, и для поиска в глубочайшем интернете не подступает. Для данной цели есть целый набор особых поисковых систем. It protects you by bouncing your communications around a distributed network of relays run by volunteers all around the world: it prevents somebody watching your Internet connection from learning what sites you visit, and it prevents the sites you visit from learning your physical location.
This set of volunteer relays is called the Tor network. The way most people use Tor is with Tor Browser , which is a version of Firefox that fixes many privacy issues. The Tor Project is a non-profit charity organization that maintains and develops the Tor software. A typical proxy provider sets up a server somewhere on the Internet and allows you to use it to relay your traffic.
This creates a simple, easy to maintain architecture. The users all enter and leave through the same server. The provider may charge for use of the proxy, or fund their costs through advertisements on the server. You just have to point your browser at their proxy server. Simple proxy providers are fine solutions if you do not want protections for your privacy and anonymity online and you trust the provider to not do bad things.
Some simple proxy providers use SSL to secure your connection to them, which protects you against local eavesdroppers, such as those at a cafe with free wifi Internet. Simple proxy providers also create a single point of failure. The provider knows both who you are and what you browse on the Internet. They can see your traffic as it passes through their server.
In some cases, they can even see inside your encrypted traffic as they relay it to your banking site or to ecommerce stores. Tor passes your traffic through at least 3 different servers before sending it on to the destination. Your traffic is encrypted between the Tor client on your computer and where it pops out somewhere else in the world.
A bad first of three servers can see encrypted Tor traffic coming from your computer. It merely sees "This IP address is using Tor". Tor is not illegal anywhere in the world, so using Tor by itself is fine. You are still protected from this node figuring out both who you are and where you are going on the Internet.
A bad third of three servers can see the traffic you sent into Tor. Most people use Tor Browser, which includes everything you need to browse the web safely using Tor. Using other browsers is dangerous and not recommended. Please add to these lists and help us keep them accurate!
Because Tor is the onion routing network. When we were starting the new next-generation design and implementation of onion routing in , we would tell people we were working on onion routing, and they would say "Neat.
Which one? Note: even though it originally came from an acronym, Tor is not spelled "TOR". Only the first letter is capitalized. There is absolutely no backdoor in Tor. If they do ask us, we will fight them, and the lawyers say probably win. We will never put a backdoor in Tor. We think that putting a backdoor in Tor would be tremendously irresponsible to our users, and a bad precedent for security software in general. If we ever put a deliberate backdoor in our security software, it would ruin our professional reputations.
Nobody would trust our software ever again — for excellent reason! But that said, there are still plenty of subtle attacks people might try. Somebody might impersonate us, or break into our computers, or something like that. Tor is open source, and you should always check the source or at least the diffs since the last release for suspicious things.
Also, there might be accidental bugs in Tor that could affect your anonymity. We periodically find and fix anonymity-related bugs, so make sure you keep your Tor versions up-to-date. The Tor software is free software. This means we give you the rights to redistribute the Tor software, either modified or unmodified, either for a fee or gratis. You will need to follow the license for those programs as well. The simplest way to obey their licenses is to include the source code for these programs everywhere you include the bundles themselves.
Is there a Tor forum? We have a StackExchange page that is currently in public beta. Before we answer, though, you should realize that Tor is never going to be blazing fast. Also, Bittorrent over Tor is not anonymous! We have millions of daily users. But the Tor network is not yet self-sustaining. Now would be an excellent time to add a few more developers to the effort so we can continue to grow the network.
However, this support is not enough to keep Tor abreast of changes in the Internet privacy landscape. Tor on Android devices is maintained by the Guardian Project. Currently, there is no supported way of using Tor on iOS; the Guardian Project is working to make this a reality in the future. Tor may attempt to connect to any port that is advertised in the directory as an ORPort for making Tor connections or a DirPort for fetching updates to the directory.
There are a variety of these ports: many of them are running on 80, , , and , but many use other ports too. When using Tor as a client, you could probably get away with opening only those four ports. See the FAQ entry on firewalled ports if you want to explicitly tell your Tor client which ports are reachable for you. There are sites you can visit that will tell you if you appear to be coming through the Tor network.
Try the Tor Check site and see whether it thinks you are using Tor or not. Use Tor Browser. You can configure it to point to Tor as a "socks4a" proxy on "localhost" port "". You need to use a separate program that understands your application and protocol and knows how to clean or "scrub" the data it sends. Tor Browser tries to keep application-level data, like the user-agent string, uniform for all users. All this and more about measuring Tor can be found at the Tor Metrics Portal.
Tor Browser does not install itself in the classic sense of applications. You just simply delete the folder or directory named "Tor Browser" and it is removed from your system. If this is not related to Tor Browser, uninstallation depends entirely on how you installed it and which operating system you have.
If you installed a package, then hopefully your package has a way to uninstall itself. The Windows packages include uninstallers. In those cases, you have three options. You will receive a reply with links from popular cloud services to download Tor Browser for Windows, Mac OS X or Linux, depending on the option you chose. Currently, the only cloud service supported is Dropbox. If you send a blank message or anything different from the options mentioned, you will receive a help message with detailed instructions to ask for Tor Browser via email.
Please note that you can use this service from any email address: gmail, yahoo, hotmail, riseup, etc. See the GetTor section for more information. Sometimes, overzealous Windows virus and spyware detectors trigger on some parts of the Tor Windows binary. Our best guess is that these are false positives — after all, the anti-virus and anti-spyware business is just a guessing game anyway. You should contact your vendor and explain that you have a program that seems to be triggering false positives.
Or pick a better vendor. In the meantime, we encourage you to not just take our word for it. Tar is a common archive utility for Unix and Linux systems. If your system has a mouse, you can usually open them by double clicking. Otherwise open a command prompt and execute. Some sites require third party browser plugins such as Flash. Plugins operate independently from Firefox and can perform activity on your computer that ruins your anonymity.
This includes but is not limited to: completely disregarding proxy settings, querying your local IP address , and storing their owncookies. It is possible to use a LiveCD solution such as or The Amnesic Incognito Live System that creates a secure, transparent proxy to protect you from proxy bypass, however issues with local IP address discovery and Flash cookies still remain.
This problem is specifically caused by the Webroot SecureAnywhere Antivirus software. We encourage affected Webroot users to contact Webroot support about this issue. Tor Browser is free software, so there is nothing preventing you from modifying it any way you like. However, we do not recommend installing any additional Firefox add-ons with Tor Browser. Add-ons can break your anonymity in a number of ways, including browser fingerprinting and bypassing proxy settings.
Some people have suggested we include ad-blocking software or anti-tracking software with Tor Browser. Tor Browser aims to provide sufficient privacy that additional add-ons to stop ads and trackers are not necessary. Additionally, maintaining a list of "bad" sites that should be black-listed provides another opportunity to uniquely fingerprint users.
Our efforts to work with the Chrome team to add missing APIs were unsuccessful, unfortunately. Currently, it is impossible to use other browsers and get the same level of protections as when using Tor Browser. This is a known and intermittent problem; it does not mean that Google considers Tor to be spyware. When you use Tor, you are sending queries through exit relays that are also shared by thousands of other users. Tor users typically see this message when many Tor users are querying Google in a short period of time.
Google interprets the high volume of traffic from a single IP address the exit relay you happened to pick as somebody trying to "crawl" their website, so it slows down traffic from that IP address for a short time. An alternate explanation is that Google tries to detect certain kinds of spyware or viruses that send distinctive queries to Google Search.
It notes the IP addresses from which those queries are received not realizing that they are Tor exit relays , and tries to warn any connections coming from those IP addresses that recent queries indicate an infection. To our knowledge, Google is not doing anything intentionally specifically to deter or block Tor use.
The error message about an infected machine should clear up again after a short time. Google uses "geolocation" to determine where in the world you are, so it can give you a personalized experience. This includes using the language it thinks you prefer, and it also includes giving you different results on your queries.
If you really want to see Google in English you can click the link that provides that. But we consider this a feature with Tor, not a bug the Internet is not flat, and it in fact does look different depending on where you are. This feature reminds people of this fact. If you set "hl" to "en" then Google will return search results in English regardless of what Google server you have been sent to.
On a query this looks like:. Another method is to simply use your country code for accessing Google. This can be google. The notification window lists a series of IP addresses and locations throughout the world recently used to access your account. It is probably a false positive, but it might not be since it is possible for someone to hijack your Google cookie.
Cookie hijacking is possible by either physical access to your computer or by watching your network traffic. In theory only physical access should compromise your system because Gmail and similar services should only send the cookie over an SSL link. And if somebody did steal your google cookie, they might end up logging in from unusual places though of course they also might not.
Tor also recognizes the torrc options Socks4Proxy and Socks5Proxy. We only support basic auth currently, but if you need NTLM authentication, you may find this post in the archives useful. If your proxies only allow you to connect to certain ports, look at the entry on Firewalled clients for how to restrict what ports your Tor will try to access. Tor Browser listens on port However, please realize that this approach is not recommended for novice users.
Privoxy has an example configuration of Tor and Privoxy. See below. On Unix, we recommend you give torsocks a try. Alternative proxifying tools like socat and proxychains are also available. The Windows way to force applications through Tor is less clear.
See ticket and ticket to follow progress there. You can then use TBB independent of that. Second complex option , you can edit your torrc file directly to add the following lines:. Are you sure you want to do this? The Tor Browser runs tor using different ports so it can co-exist happily with the tor process already running on your system. Furthermore if you are running a relay, it may be better to run another tor instance for all of your personal Tor usage.
If this does not work or randomly clobbers your torrc, you are on your own. Add the user you will be running Tor Browser as to the debian-tor group. Set the following environment variables:. If you wish to use password authentication for the control port, you will need to wait till is fixed. Following settings can be changed but be aware that this is not recommended and can harm your anonymity. That way we have a much lower risk of an old tor process hanging around if the browser is killed or if it crashes.
There are Firefox preferences that correspond to some of the environment variables. If an env variable is set the equivalent preference setting is overwritten:. One of the huge new features in TBB 3. Part of creating identical builds is having everybody use the same timestamp. Mike picked the beginning of for that time. The reason you might see 7pm in is because of time zones. Tor Browser is built from the tor-browser-build.
There is also some informations in the Tor Browser Hacking Guide. Tor uses a text file called torrc that contains configuration instructions for how your Tor program should behave. The default configuration should work fine for most Tor users. For the tor service on Windows see Windows NT.
Otherwise, if you are using Tor without Tor Browser, it looks for torrc at differentt possible locations:. On Debian use system tor reload. For advanced users, note that you actually only need to send Tor a HUP signal, not actually restart it. Have a look at the sample torrc file for hints on common configurations. Here are some likely places for your logs to be:.
To change your logging setup by hand, edit your torrc and find the section near the top of the file which contains the following line:. For example, if you want Tor to send complete debug, info, notice, warn, and err level messages to a file, append the following line to the end of the section:. Alas, some of the warn messages are hard for ordinary users to correct -- the developers are slowly making progress at making Tor automatically react correctly for each situation.
We recommend running at the default, which is "notice". Tor relays in particular should avoid logging at info or debug in normal operation, since they might end up recording sensitive information in their logs. If Tor can establish a circuit, Tor Browser will automatically launch the browser for you. You can also check in the Tor logs for a line saying that Tor "has successfully opened a circuit.
Looks like client functionality is working. We want to hear from you! There are supposed to be zero crash bugs in Tor. This FAQ entry describes the best way for you to be helpful to us. Second, make sure your version of libevent is new enough. We recommend at least libevent 1. If so, check if there are any new details that you can add. Fourth, is the crash repeatable? Can you cause the crash? Can you isolate some of the circumstances or config options that make it happen?
How quickly or often does the bug show up? Can you check if it happens with other versions of Tor, for example the latest stable release? You can look at the log-configuration FAQ entry for instructions on what to put in your torrc file. If it usually takes a long time for the crash to show up, you will want to reserve a whole lot of disk space for the debug log. You can set preferred entry and exit nodes as well as inform Tor which nodes you do not want to use.
The following options can be added to your config file torrc or specified on the command line:. We recommend you do not use these — they are intended for testing and may disappear in future versions. Note also that not every circuit is used to deliver traffic outside of the Tor network. It is normal to see non-exit circuits such as those used to connect to onion services, those that do directory fetches, those used for relay reachability self-tests, and so on that end at a non-exit node.
Make sure there are no spaces between the commas and the list items. See the manual page for details. If your firewall works by blocking ports, then you can tell Tor to only use the ports when you start your Tor Browser. Or you can add the ports that your firewall permits by adding "FascistFirewall 1" to your torrc configuration file. You can select a different set of ports with the FirewallPorts torrc option.
If you want to be more fine-grained with your controls, you can also use the ReachableAddresses config options, e. The default open ports are listed below but keep in mind that, any port or ports can be opened by the relay operator by configuring it in torrc or modifying the source code.
A relay will block access to its own IP address, as well local network IP addresses. A relay always blocks itself by default. Applications that do DNS resolves themselves may leak information. Consider using Socks4A e. If you are running Tor to get anonymity, and you are worried about an attacker who is even slightly clever, then yes, you should worry.
The Problem. When your applications connect to servers on the Internet, they need to resolve hostnames that you can read like www. To do this, your application sends a request to a DNS server, telling it the hostname it wants to resolve.
Clearly, this is a bad idea if you plan to connect to the remote host anonymously: when your application sends the request to the DNS server, the DNS server and anybody else who might be watching can see what hostname you are asking for. Even if your application then uses Tor to connect to the IP anonymously, it will be pretty obvious that the user making the anonymous connection is probably the same person who made the DNS request.
If you think that you applied one of the solutions properly but still experience DNS leaks please verify there is no third-party application using DNS independently of Tor. These are two steps you need to take here. Step one: add "TestSocks 1" to your torrc file, and then watch your logs as you use your application.
If you suspect your application might behave like this, you should use a network sniffer like Wireshark and look for suspicious outbound DNS requests. By default, your Tor client only listens for applications that connect from localhost. Connections from other computers are refused. If you want to torify applications on different computers than the Tor client, you should edit your torrc to define SocksListenAddress 0.
If you want to get more advanced, you can configure your Tor client on a firewall to bind to your internal IP but not your external IP. Tor can be configured as a client or a relay on another machine, and allow other machines to be able to connect to it for anonymity.
This is most useful in an environment where many computers want a gateway of anonymity to the rest of the world. You can state multiple listen addresses, in the case that you are part of several networks or subnets.
When setting up your SocksListenAddress es , you need to give the port with the address, as shown above. IPv6 is supported since Tor version 0. To activate it add the following two entries into your torrc file:. If you are interested in developing you can review the IPv6 implemetation status at our IPv6Features wiki page, known issues can be found with the ipv6 keyword.
The exit relay is the most needed relay type but it also comes with the highest legal exposure and risk and you should NOT run them from your home. If you are looking to run a relay with minimal effort, fast guard relays are also very useful followed by bridges. If your relay is relatively new then give it time. Tor decides which relays it uses heuristically based on reports from Bandwidth Authorities. The lifecycle of a new relay is explained in more depth in this blog post.
Tor can handle relays with dynamic IP addresses just fine. Just leave the "Address" line in your torrc blank, and Tor will guess. For the time being Tor will require IPv4 addresses on relays, you can not run a Tor relay on a host with IPv6 addresses only. If you allow exit connections, some services that people connect to from your relay will connect back to collect more information about you.
For example, some IRC servers connect back to your identd port to record which user made the connection. Also, users exiting from you might attract the attention of other users on the IRC server, website, etc. Another reason is that groups who scan for open proxies on the Internet have learned that sometimes Tor relays expose their socks port to the world.
We recommend that you bind your socksport to local networks only. In any case, you need to keep up to date with your security. See this article on operational security for Tor relays for more suggestions. See this tor-relays thread. All outgoing connections must be allowed, so that each relay can communicate with every other relay. In many jurisdictions, Tor relay operators are legally protected by the same common carrier regulations that prevent internet service providers from being held liable for third-party content that passes through their network.
Exit relays that filter some traffic would likely forfeit those protections. Tor promotes free network access without interference. Exit relays must not filter the traffic that passes through them to the internet. Exit relays found to be filtering traffic will get the BadExit flag once detected. Otherwise, you could drop many packets during periods of maximum bandwidth usage -- you may need to experiment with which values make your connection comfortable.
Then set BandwidthBurst to the same as BandwidthRate. Linux-based Tor nodes have another option at their disposal: they can prioritize Tor traffic below other traffic on their machine, so that their own personal traffic is not impacted by Tor load. Additionally, there are hibernation options where you can tell Tor to only serve a certain amount of bandwidth per time period such as GB per month.
These are covered in the hibernation entry below. The accounting options in the torrc file allow you to specify the maximum amount of bytes your relay uses for a time period. This specifies when the accounting should reset. For instance, to setup a total amount of bytes served for a week that resets every Wednesday at am , you would use:. This specifies the maximum amount of data your relay will send during an accounting period, and the maximum amount of data your relay will receive during an account period.
When the accounting period resets from AccountingStart , then the counters for AccountingMax are reset to 0. It will keep track of how quickly it used its quota in the last period, and choose a random point in the new interval to wake up. This way we avoid having hundreds of relays working at the beginning of each month but none still up by the end. Just divide your monthly amount by For example, if you have 50 GB to offer each way, you might set your RelayBandwidthRate to KBytes: this way your relay will always be useful for at least half of each day.
But there are a few exceptions:. If you open your DirPort, then Tor clients will ask you for a copy of the directory. This probably accounts for most of the difference between your "write" byte count and your "read" byte count. Another minor exception shows up when you operate as an exit node, and you read a few bytes from an exit connection for example, an instant messaging or ssh connection and wrap it up into an entire byte cell for transport through the Tor network.
The parameters assigned in the AccountingMax and BandwidthRate apply to both client and relay functions of the Tor process. Thus you may find that you are unable to browse as soon as your Tor goes into hibernation, signaled by this entry in the log:. The solution is to run two Tor processes - one relay and one client, each with its own config. One way to do this if you are starting from a working relay setup is as follows:. Each Tor relay has an exit policy that specifies what sort of outbound connections are allowed or refused from that relay.
The exit policies are propagated to Tor clients via the directory, so clients will automatically avoid picking exit relays that would refuse to exit to their intended destination. This way each relay can decide the services, hosts, and networks it wants to allow connections to, based on abuse potential and its own situation. The default exit policy allows access to many popular services e. This setting means that your relay will be used for relaying traffic inside the Tor network, but not for connections to external websites or other services.
If you do allow any exit connections, make sure name resolution works that is, your computer can resolve Internet addresses correctly. This tells Tor to avoid exiting through that relay. In effect, relays with this flag become non-exits. Please reach out to the bad-relays team so we can sort out the issue. Several countries, including China and Iran, have found ways to detect and block connections to Tor bridges.
So should you run a normal relay or bridge relay? If you have lots of bandwidth, you should definitely run a normal relay. Thanks for volunteering! Note: As of Tor 0. Eventually they will replace the old RSA identities, but that will happen in time, to ensure compatibility with older versions.
As of Tor 0. In simple words, it works like this:. If you want to use this feature, you can consult our more detailed guide on the topic. If you want to keep using the old key, see the Upgrading your Tor relay FAQ entry for how to restore the old identity key. A service called Tor Win32 Service will be installed and started. This service will also automatically start every time Windows boots, unless you change the Start-up type. An easy way to check the status of Tor, start or stop the service, and change the start-up type is by running services.
Optionally, you can specify additional options for the Tor service using the -options argument. The uninstaller is currently not capable of removing the active service. Competent vserver admins are able to configure your server to not hit these limits. Look for "failcnt" in tcpsndbuf, tcprecvbuf, numothersock, and othersockbuf. Ask for these to be increased accordingly. Xen, Virtual Box and VMware virtual servers have no such limits normally.
If the vserver admin will not increase system limits another option is to reduce the memory allocated to the send and receive buffers on TCP connections Tor uses. An experimental feature to constrain socket buffers has recently been added. If your version of Tor supports it, set "ConstrainedSockets 1" in your configuration.
See the tor man page for additional details about this option. Unfortunately, since Tor currently requires you to be able to connect to all the other Tor relays, we need you to be able to use at least file descriptors. We hope to fix this in the future, once we know how to build a Tor network with restricted topologies -- that is, where each node connects to only a few other nodes.
But this is still a long way off. If you do decide to run more than one relay, please set the "MyFamily" config option in the torrc of each relay, listing all the relays comma-separated that are under your control:. That way clients will know to avoid using more than one of your relays in a single circuit. Tor guesses its IP address by asking the computer for its hostname, and then resolving that hostname.
Also, if you have many addresses, you might also want to set "OutboundBindAddress" so external connections come from the IP you intend to present to the world. See portforward. If your relay is running on a internal net you need to setup port forwarding. Forwarding TCP connections is system dependent but the firewalled-clients FAQ entry offers some examples on how to do this.
You may have to change "eth0" if you have a different external interface the one connected to the Internet. All of this said, fast Tor relays do use a lot of ram. It is not unusual for a fast exit relay to use MB of memory. The simplest example is an attacker who owns a small number of Tor relays.
There are also some downsides to running a Tor relay. It is an open research question whether the benefits outweigh the risks. A lot of that depends on the attacks you are most worried about. Exonerator is a web service that can check if an IP address was a relay at a given time. We recommend these non-profit charities that are happy to turn your donations into better speed and anonymity for the Tor network:. Note that there can be a tradeoff here between anonymity and performance.
At the same time though, economies of scale for bandwidth mean that combining many small donations into several larger relays is more efficient at improving network performance. Improving anonymity and improving performance are both worthwhile goals, so however you can help is great! Since the. Currently, the Tor directory server provides this look-up service; and thus the look-up request must get to the Tor network. Therefore, your application needs to pass the. So, how do you make your application pass the hostname directly to Tor?
This will allow you to use almost any program with Tor without leaking DNS lookups and allow those same programs to access onion services. Versions of Tor before 0. Starting with 0. The stuff in parenthesis is optional. Only one release is ever made with any given set of these version numbers. The TAG lets you know how stable we think the release is: "alpha" is pretty unstable; "rc" is a release candidate; and no tag at all means that we have a final release.
So for example, we might start a development branch with say 0. The patchlevel increments consistently as the status tag changes, for example, as in: 0. Eventually, we would release 0. The next stable release would be 0. Why do we do it like this? Because every release has a unique version number, it is easy for tools like package manager to tell which release is newer than another.
The tag makes it easy for users to tell how stable the release is likely to be. To set up your own Tor network, you need to run your own authoritative directory servers, and your clients and relays must be configured so they know about your directory servers rather than the default public ones. Apart from the somewhat tedious method of manually configuring a couple of directory authorities, relays and clients there are two separate tools that could help. One is Chutney, the other is Shadow.
Chutney is a tool for configuring, controlling and running tests on a testing Tor network. It requires that you have Tor and Python 2. You can use Chutney to create a testing network by generating Tor configuration files torrc and necessary keys for the directory authorities. Then you can let Chutney start your Tor authorities, relays and clients and wait for the network to bootstrap. Finally, you can have Chutney run tests on your network to see which things work and which do not.
Chutney is typically used for running a testing network with about 10 instances of Tor. Every instance of Tor binds to one or two ports on localhost Shadow is a network simulator that can run Tor through its Scallion plug-in. Shadow can be run on any linux machine without root, and can also run on EC2 using a pre-configured image. Also, Shadow controls the time of the simulation with the effect that time-consuming tests can be done more efficiently than in an ordinary testing network.
The Shadow wiki and Shadow website are good places to get started. A fully Java implementation of the Tor client is now available as Orchid. We still consider Orchid to be experimental, so use with care. One is multithreading: you have a separate micro-program inside the main program for each net connection that reads and writes to the connection as needed.
This, performance-wise, sucks. And the newest ways are finally fast, but are not available on all platforms. However, On the the Win32 platform by Microsoft the only good way to do fast IO on windows with hundreds of sockets is using overlapped IO, which is grossly unlike every other BSD sockets interface.
Internet communication is based on a store-and-forward model that can be understood in analogy to postal mail: Data is transmitted in blocks called IP datagrams or packets. Every packet includes a source IP address of the sender and a destination IP address of the receiver , just as ordinary letters contain postal addresses of sender and receiver.
The way from sender to receiver involves multiple hops of routers, where each router inspects the destination IP address and forwards the packet closer to its destination. Thus, every router between sender and receiver learns that the sender is communicating with the receiver. In particular, your local ISP is in the position to build a complete profile of your Internet usage. In addition, every server in the Internet that can see any of the packets can profile your behaviour.
The aim of Tor is to improve your privacy by sending your traffic through a series of proxies. Your communication is encrypted in multiple layers and routed via multiple hops through the Tor network to the final receiver. Note that all your local ISP can observe now is that you are communicating with Tor nodes.
Similarly, servers in the Internet just see that they are being contacted by Tor nodes. First, Tor prevents websites and other services from learning your location, which they can use to build databases about your habits and interests. Because these relays are run by different individuals or organizations, distributing trust provides more security than the old one hop proxy approach.
Note, however, that there are situations where Tor fails to solve these privacy problems entirely: see the entry below on remaining attacks.