BitTorrent Details How It’s Building An Anonymous Chat Product Without Using Servers

BitTorrent is publishing a blog post with more details about its in-development chat product, which it announced in September with the stated goal of ensuring “that your messages stay yours: private, secure, and free.”

The announcement was short on details, so this seems to be the first look at how BitTorrent Chat will actually work., The company says that since it’s taking a decentralized approach, where your messages don’t go through any of BitTorrent’s servers (as illustrated in the infographic below), the product won’t have any user names. Instead, it will use a process called public-key cryptography.

As I understand it, that means if two people want to chat, they exchange their public keys (essentially a string of numbers) with each other. When I was discussing this with a BitTorrent spokesperson, he confirmed that’s how it will work, but he added, “there are other simpler ways that we also support for people who are less technical.”

In the BitTorrent blog post, software engineer Abraham Goldoor writes that you’ll be able to use Chat without telling anyone your real name, and he adds:

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.

Goldoor also writes that like BitTorrent’s other products, BitTorrent Chat will use a distributed hash table to find IP addresses — which, again, is supposed to allow users find each other without going through a server.

For obvious reasons, people may be particularly interested in keeping their messages out of the hands of any company right now, and this isn’t the first privacy-focused product that BitTorrent has launched this year.

We also asked the company about other chat services like Telegram.org (which BitTorrent pointed out still stores messages in the cloud) and Skype (which we use for messaging at TechCrunch). Regarding Skype, the BitTorrent spokesperson replied, “Nobody knows how Skype is doing what they are doing. So we cannot really compare it on a technical level. But it is assumed they are entirely server based since being acquired by eBay and subsequently Microsoft.” (I’ve asked Skype if they want to comment and will update if they do.)

BitTorrent still isn’t saying when its chat product will actually become available, but you can sign up for the private alpha here.