BitTorrent, a popular Peer 2 Peer (P2P) torrent client is creating a serverless instant messaging system that depends on public key encryption to shield the privacy of communications, distinguishing people by only cryptographic key pairs.
This new project was announced in September and unveiled some information on how it will work in a blog post today. The blog post states:
With BitTorrent Chat, there aren’t any “usernames” per se. You don’t login in the classic sense. Instead, your identity is a cryptographic key pair. To everyone on the BitTorrent Chat network at large, you ARE your public key. This means that, if you want, you can use Chat without telling anyone who you are. Two users only need to exchange each other’s public keys to be able to chat.
Using public key encryption provides us with a number of benefits. The most obvious is the ability to encrypt messages to your sender using your private key and their public key. But in public key encryption, if someone gains access to your private key, all of your past (and future) messages could be decrypted and read. In Chat, we are implementing forward secrecy. Every time you begin a conversation with one of your contacts, a temporary encryption key will be generated. Using each of your keypairs, this key will be generated for this one conversation and that conversation only, and then deleted forever.
This system is really a Distributed Hash Table (DHT) which will finds IP addresses, eliminating the requirement of a main server to route communications, this company explained.
“If you understand the fundamentals of the DHT, you might be wondering, ‘How is a DHT more secure? Aren’t you giving your IP address out to the entire DHT? That’s LESS secure than a central server!'” BitTorrent said. “With Chat, we are expanding on what we can use the DHT for. We have updated our DHT protocol to support encryption. The new DHT protocol enables users to find each other securely and privately.”
BitTorrent, Inc. is not announcing when Chat is going to be readily available, but Averill, a spokes person for BitTorrent stated it will probably stick to a related development routine as BitTorrent Sync, a file syncing program, similar to Dropbox, but it depends on P2P technology. That might imply a non-public alpha testing stage could be accompanied by a public alpha a couple of months and finally a beta release a month or two following.