TorChat was a

peer-to-peer Peer-to-peer (P2P) computing or networking is a distributed application architecture that partitions tasks or workloads between peers. Peers are equally privileged, equipotent participants in the network. They are said to form a peer-to-peer ...

anonymous

instant messenger Instant messaging (IM) technology is a type of online chat allowing real-time text transmission over the Internet or another computer network. Messages are typically transmitted between two or more parties, when each user inputs text and tri ...

that used

Tor Tor, TOR or ToR may refer to: Places * Tor, Pallars, a village in Spain * Tor, former name of Sloviansk, Ukraine, a city * Mount Tor, Tasmania, Australia, an extinct volcano * Tor Bay, Devon, England * Tor River, Western New Guinea, Indonesia Sc ...

onion service Tor, short for The Onion Router, is free and open-source software for enabling anonymous communication. It directs Internet traffic through a free, worldwide, volunteer overlay network, consisting of more than seven thousand relays, to con ...

s as its underlying network. It provided cryptographically secure text messaging and file transfers. The characteristics of Tor's onion services ensure that all traffic between the clients is encrypted and that it is very difficult to tell who is communicating with whom and where a given client is physically located. TorChat is free software licensed under the terms of the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general ...

(GPL).

Features

In TorChat every user has a unique alphanumeric ID consisting of 16 characters. This ID will be randomly created by Tor when the client is started the first time, it is basically the

.onion .onion is a special-use top level domain name designating an anonymous onion service, which was formerly known as a "hidden service", reachable via the Tor network. Such addresses are not actual DNS names, and the .onion TLD is not in the I ...

address of an onion service. TorChat clients communicate with each other by using Tor to contact the other's onion service (derived from their ID) and exchanging status information, chat messages and other data over this connection. Since onion services can receive incoming connections even if they are behind a router doing network address translation (NAT), TorChat does not need any

port forwarding In computer networking, port forwarding or port mapping is an application of network address translation (NAT) that redirects a communication request from one address and port number combination to another while the packets are traversing a ne ...

to work.

History

The first public version of TorChat was released in November 2007 by Bernd Kreuss (prof7bit). It is written in

Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (pro ...

and used the cross-platform widget toolkit

wxPython wxPython is a wrapper for the cross-platform GUI API (often referred to as a "toolkit") wxWidgets (which is written in C++) for the Python programming language. It is one of the alternatives to Tkinter. It is implemented as a Python extensio ...

which made it possible to support a wide range of platforms and

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also i ...

s. The older Windows versions of TorChat were built with py2exe (since 0.9.9.292 replaced with pyinstaller) and came bundled with a copy of Tor readily configured so that it could be run as a

portable application A portable application (portable app), sometimes also called standalone, is a program designed to read and write its configuration settings into an accessible folder in the computer, usually in the folder where the portable application can be f ...

right off a

USB flash drive Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply ( interfacing) between computers, peripherals and other computers. A bro ...

without any installation, configuration or account creation. Between 2008 and 2010 weren't any updated packages, resulting in the bundled version of Tor becoming obsolete and unable to connect to the Tor network, which was the reason for the appearance of forks that basically just replaced the bundled Tor.exe with a current one. In December 2010, an official update finally became available that, among some minor bugfixes, also again included an up-to-date Tor.exe. After 2014, all development activity stopped and TorChat has not received any further updates.

Forks

A fork was released for OS X in the summer of 2010 by a French developer. The binary (a Cocoa application) and source-code (Objective-C) bundled in a

Xcode Xcode is Apple's integrated development environment (IDE) for macOS, used to develop software for macOS, iOS, iPadOS, watchOS, and tvOS. It was initially released in late 2003; the latest stable release is version 14.2, released on December 13, ...

7 project can be downloaded on SourceMac. A rewrite of the TorChat protocol in

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...

was created in the beginning of 2012, called jTorChat on

Google Code Google Developers (previously Google Code) , application programming interfaces (APIs), and technical resources. The site contains documentation on using Google developer tools and APIs—including discussion groups and blogs for developers usi ...

. Containing the latest Tor.exe, it is meant to emulate all the features of the original TorChat protocol, as well as extending the protocols for jTorChat-specific features. Filesharing, while implemented in the original TorChat, is not yet implemented in jTorChat. A new capability in jTorChat is the broadcast mode, which allows a user to send messages to everybody in the network, even if they are not in their buddylist. Also buddy request mode is implemented, which allows a user to request a random user in the jTorChat network to add them. At this stage jTorChat is designed to work effectively on Windows without any configuration, however since its written in

, it can run on any platform supported by both, Tor and Java itself, making it very portable. The project is actively seeking Java contributors, especially to help debug the GUI interface. In February 2012, developer Prof7bit moved TorChat to

GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continu ...

, as a protest against Google selectively censoring access to TorChat download to certain countries. Prof7bit has switched to working on torchat2, which is a rewrite from scratch, using Lazarus and

Free Pascal Free Pascal Compiler (FPC) is a compiler for the closely related programming-language dialects Pascal and Object Pascal. It is free software released under the GNU General Public License, witexception clausesthat allow static linking against its ...

Security

In 2015 security analysis of TorChat protocol and its Python implementation was conducted. It was found that although the design of TorChat is sound, its implementation has several flaws, which make TorChat users vulnerable to impersonation, communication confirmation and denial-of-service attacks. Despite the flaws found, the use of TorChat might still be secure in a scenario where the peer's onion address does not become known to an adversary interested in attacking the person behind the TorChat address.

References

External links