Retroshare – Secure, Private File-Sharing

April 4, 2012
The file-sharing world has been turned upside down in recent months.

Even though file-sharing has legitimate uses, all it takes is one rogue user — probably an anonymous individual from another country — to upload a restricted file using your service, and that, if discovered, can cause the copyright cartel to invoke the powers of the state upon your system, leading to raids, seizures, and prosecution — even across international boundaries.

Many people need a file-sharing system whether for personal use or to conduct business, so is there any way to share files with only the people you trust so that unknown users cannot share files that could put you in trouble?

A number of alternate file-sharing systems are gaining recognition quickly in answer to this question, and one such program is Retroshare.

What Is Retroshare?

Retroshare is a highly secure, private peer-to-peer (P2P) and friend-to-friend (F2F) file-sharing program that allows users to share files among themselves on a private system across a LAN or across the Internet. In addition, it supports its own chat, email, forums, and messaging systems, which are encrypted to keep your conversations and file transfers private.

Anyone with Retroshare and access to your Retroshare network may partake of the fun. Not just anybody can hop onto your network using Retroshare like he can with a Bittorrent client. A system of authentication is required on both sides.

You Need a Key to Enter

Before anyone can connect, each user must have his own public/private key since Retroshare uses GPG to validate users. (Linux already has GPG built-in, but Windows users might need additional hand-holding in this area, so please see the Retroshare web site for details.)

With keys obtained, all users must share their public keys with each other. Suppose we have two users, Inky and Blinky, who wish to share files. By default, they cannot connect to or see each other, so Inky sends his public key to Blinky, and Blinky sends his public key to Inky. (The key can be shared in a variety of ways, such as by email, sneakernet, FTP, SSH, mailing a USB thumb drive, or whatever.)

Key files (.rsc certificates), copy and paste, and email invitations make it easy to add users to a Retroshare network.

Once each user’s Retroshare program contains each user’s public key, the two users automatically connect. They can then transfer files, engage in live chat, host their own private forums, gossip, or play around. Best of all, ALL communications are encrypted using OpenSSL, so ISPs and other sniffers cannot spy on your Retroshare communications. This makes it hard for others to find out what you and your friends are doing. Even file transfers are encrypted.

When other friends wish to connect to your network, they must give you their public keys and you must give them yours. This prevents anonymous, unknown users from connecting to your private network. You have to know each other first. By using the two-way key trading system, you know who you are connecting to and others know who you are within your own private group of close friends. This allows friends of a friend to also connect. Strangers, snoops, and whistle blowers are excluded unless you have a traitor in your midst.

The initial setup can be involving. Due to its security features, Retroshare is not an install and go program. It requires setup before use.

Private Sharing Network

Retroshare networks are private. By default, Retroshare will attempt to automatically connect
to other users it already knows about, but you can create a true Darknet using Retroshare. Darknets are private, secret, exclusive networks, and they have been around for a long time.  (Research Darknets. It’s interesting!) Darknets rarely appear in search engine results, because you need to be a part of the club before you can have access. This is why they are called Darknets. Adjusting the Retroshare options gives you plenty of control over the type of connections you wish to perform (DHT, Discovery, UPNP, Network configuration, Dynamic DNS, and more).

A network map that updates in real time shows how users are connected to each other.

Retroshare options are plenty. You can customize practically any aspect of the program, so be prepared to invest some time learning how Retroshare works.

A few Retroshare options.

Shared Directories

You can search for specific files or browse through the shared directories of other users. By default, nothing is shared. You must specify which directories on your computer to share with others.

Specify which directories to share. ( /etc is for demonstration only. You would not want to share it in real life.)

Once shared, all files inside the shared directory are available to others connected to your Retroshare network.

File Transfers

File transfers operate similar to Bittorrent, not FTP or SSH, because peers host the files. Initially, file transfers are slow, but they speed up as you connect to more peers. In addition, upload and download limits can be set manually for each peer, so this affects the transfer speed.

During my tests, I found FTP and SSH file transfers to be faster than Retroshare. This was probably because FTP and SSH are client-server systems while Retroshare is a P2P system. However, file transfers were tested across a LAN, and the transfer rate was still faster than what was available across the Internet.

News Feed

The Friends button in the menu bar opens one of the most convenient features I have seen in a file-sharing program: The News Feed.

This is a window that functions like an RSS channel. It displays events as they happen, such as who wants to connect, who has connected, messages received, and so on, complete with user icons and other info. It lets you know that your Retroshare network is alive by showing you who is online and what he is doing. You can send quick messages and open chat sessions from here.

News Feed shows activity.

Retroshare sets itself up as a private email system. 

How much do we trust each other?

Host your own forums and ponder the questions that really matter.


Shhh! This conversation is private and encrypted. Multi-user chat rooms are also possible.

The built-in Tetris easter egg alleviates bouts of boredom.


Retroshare is comprehensive and well thought out to address the needs of private file-sharing. It’s more than a file-sharing program, it’s a way to stay in touch with friends you trust privately. Even when not transferring files, you can leave Retroshare running as a chat and private email system.

Since Retroshare works across LANs and the Internet, you can create your own virtual network that feels like a private club for exclusive members. Everyone must know everyone else and must gain permission before connecting.

Retroshare is free, Open Source, and available for Linux, Mac OS X, and Windows. If you enjoy sharing files with your friends and seek a secure, private means of doing so, then give Retroshare a try.


, , , , , ,

  1. Zonet ZSR4174WE – Wireless Networking on the Go « Delightly Linux

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: