RetroShare - a tool for private communication and data sharing

After a year of being in the beta and release candidate status, the final release of Retroshare version 0.6.0 took place.

The program has been developing for 10 years now. The previous version 0.5.5 was released in the fall of 2013 and gained considerable popularity among cryptographic specialists, enthusiasts of decentralized networks and ordinary Internet users, for whom the security of file sharing and communication is not an empty sound. However, it should be noted that on one of the most popular resources of the RuNet there is not a single material about the RetroShare cryptoplatform, a couple of references to it were found only in the comments. The following text can be considered a modest attempt to correct this omission.

So, Retroshare is a cryptographically protected decentralized platform for anonymous communication and file sharing. The system allows you to organize separate serverless Friend-to-Friend networks or one global network (which actually exists today) with a certain circle of people - for example, your friends, family, colleagues or just strangers. Connections are established directly only with those participants to whom you have given permission. This is an important feature that moves such networks into a special class of decentralized networks in which unauthorized connection to your computer is prohibited without your goodwill. Networks of this type are called "Private p2p", "Darknet" or simply "Dark network".

Dark nets like RetroShare, among other things, have two important characteristics:
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1) it is difficult to monitor the user's file-sharing and communication activities from outside, that is, from a potential adversary who is not connected to the network;
2) outside the so-called “near” environment of the RetroShare network (and the like - FreeNet, GNUnet) it is not possible to reliably determine even the fact of the user's connection to such a network.

The first feature essentially distinguishes dark (private) anonymous networks from public anonymous networks, where statistics, for example, by the IP addresses of the participating nodes are dialed by simple direct observation of the network connection or without it. The second sign is a direct consequence of the fact that connecting to an arbitrary network node is impossible without confirmation of such an operation by the counterparty.

It should be particularly noted that even within the so-called “trusted” environment, it is possible to communicate and exchange data through the system of anonymous individuals, whose identifier is not tied to the user's personal certificate. The number of created anonymous personalities is not limited; the user is free as necessary and / or external factors to arbitrarily create and delete their personalities.

All connections are securely encrypted by SSL, authenticated by PGP keys. The system is not subject to censorship and any outside control or monitoring because of its distributed structure, and is resistant to blocking and other manifestations of foreign hostile interests.



Opportunities:

- Instant messaging and mail
- Public and private chat rooms
- VoIP - Voice and video communication
- File sharing
- Forums
- Channels

Despite the consequence of the p2p nature, as well as the specifics of the network, linked primarily to the anonymization of the user - the file transfer speed approaches the maximum bandwidth of your channel.

Messaging is possible on behalf of anonymous individuals, and directly between network nodes. In the first case, offline delivery is available, message storage is used on the nodes of mutual friends. Voice and video communication is available only for communication of nodes from the trusted environment. That is, with those nodes with which certificates were previously exchanged.

The system of anonymous identifiers (personalities) also provides the ability to communicate with people outside the circle of your friends, messages are transmitted along a chain of successively connected nodes. Thus, it is possible to communicate with any member of the network, incl. with which the connection is not established.

Forums are fully distributed, and distributed on a subscription basis. The forum that interests you is mirrored on your site and becomes available to your entire environment. Any one of your surroundings has the opportunity to subscribe to the forum of interest to him and, thus, valuable content “spreads” far off the network, and the distribution of litter is hampered or blocked altogether. Forums are available offline for reading and posting; Of course, synchronization with other participants is performed only when communicating with them.

Version 0.6 introduces an anti-vandal system based on an extremely simple, but effective, reputation system. Individuals can put a negative mark and then all their messages will be ignored. These ratings are distributed among friends and allow you to quickly ban bullies. The system, if necessary, is disabled.

File sharing is more like emule and direct connect than bittorrent. It can be said that the best properties were taken from all the listed systems. Files are identified separately, by SHA-hash and, therefore, remain available regardless of renaming and / or moving within an open access folder. File links represent a simple text block with a name and a hash, similar to ed2k and magnet.

No interim measures as .torrent files are required. But if you wish, you can organize a group of files in a compact form, for which support is provided for collection files containing a set of links in text form.

Files are shared by entire folders. Individual folders can be given different access rights, for this there is a unique opportunity for decentralized networks to join friends into groups.

Folders can be shared both in an explicit mode — friends can browse the content, or in anonymous mode — the view is not available. In this case, the files are available for download if the user has detected their presence on the network through a powerful search service.

Search is possible not only on the sites of friends, but also across the entire available network, thanks to the data tunneling mechanism. There are many options for specifying the search, for example, by extension, hash, etc. Downloading is carried out in several streams from all available "directions".

Connections are established over TCP / UDP IPv4, in the development of IPv6-transport. It is possible to work through tor / i2p anonymizing networks. To facilitate communication in the case of dynamic addresses, uPnP, DynDNS, DHT and a system for exchanging contact information between common friends are used. If necessary, everything is off.

The traditional question: why do we need another cryptosystem?

The fact is that Retroshare is probably the first platform that provides reliable and secure cryptography in a relatively easy to use format. And this is not just a thing in itself, cryptography for the sake of cryptography. It provides many efficient and useful services at once.

It is enough for two people to exchange public keys once (in any convenient way) - and after the connection is established, all possibilities will be available.

No conditions, asterisks and small print. All this is available for free, without registration and SMS. Open Source. The owner is you.

As part of the objectivity of the consideration of the subject: in a barrel of honey ... of course, there are problems, flaws and shortcomings. For example:

- VOiP is not yet debugged, the quality is lame and not comparable with Skype and analogues.
- Some functions that have become familiar in other systems are not enough, such as streaming - playback during the media file loading process
- The interface seems overwhelmed by a considerable number of users - a consequence of the abundance of functions.

Of course over all of this work is underway. However, as in any other project, which is based on serious cryptography, the developers first of all solve the problems of improving the platform core, and therefore the security problems.

You should also consider the features of distributed and cryptographic systems:

- There is no possibility to delete the sent messages and posts.
- There is no possibility to recover a forgotten password. Change it is also impossible.
- With the loss of a key or the collapse of the disk with the profile there is no possibility to recover data.
- In order to prevent the endless growth of occupied volumes, there are restrictions on the storage time of messages. Forums - 1 year, channels - 4 months. To be fair, these parameters can be revised in perspective if the free community of RetroShare makes such a decision.

The client is open source, written in Qt / C ++, there are builds for all common desktop operating systems, there is an experience of successful launch on Android. There is support for plug-ins to extend functionality.

There is an opportunity to work in no-gui mode, in the presence of a web-interface.

In the near future, the development of a system of so-called circles, to delimit access to resources by groups of friends. In the development of distributed wiki-sites, in the plans of the Wall (by analogy with facebook), and even a lot of usefulness, the full list of which is available here . Despite the small number of developers, active work is underway to improve the program.

References:

Official website: retroshare.sf.net
Developer Blog: retroshareteam.wordpress.com
Source Code: github.com/RetroShare
Russian resource: adorabilis.wordpress.com
Connection instructions: ruretroshare.net
Servers for access to public chat rooms: retroshare.rocks
See also: Theory of Six Handshakes