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How BitTorrent Will Keep Your Chats Private

If you've ever used BitTorrent downloading software for questionable purposes, you'll be pleased to know that the BitTorrent company's upcoming chat service will also hide your conversations from prying eyes. By using public key encryption, the information-sharing company hopes to make chats both private and inaccessible after the fact.

The program, called BitTorrent Chat, is currently in its alpha state. Interested users can sign up for a mailing list that will provide further information on how to take part. If you just can't wait to find out how the program will protect your privacy, though, the BitTorrent engineers took to the company's blog to explain a thing or two about BitTorrent's public key encryption technology.

The post, which is not overly technical, explains that most chat services rely on two users communicating via a central server. When you say "Hi" to your friend via Gchat, for example, that message first goes to Google's server, which may or may not be secure, and then to your friend's PC.

MORE: 10 Best Desktop Bittorrent Clients for P2P Sharing

Internet chats using public key encryption need to work a little differently. Such chat protocols provide users with two keys — one public, one private, and both mathematically linked — and requires authentication both with a decentralized network (not a monolithic server) and between users.

With public-key encryption, only you and your chat buddy can read your messages. It's just about impossible for third parties to intercept the messages, and even if they do, the algorithms are generally too complex to decipher without prolonged and concentrated decryption procedures.

Taking this idea one step further, BitTorrent Chat users will not have traditional usernames at all; instead, they will simply be identified by their public encryption keys. Users who want to reveal themselves are welcome to do so; otherwise, they'll be just about impossible to pinpoint.

Furthermore, there will be no central server relaying messages to and from users. Rather, communications will be direct, peer-to-peer links. Users need only access a distributed hash table (DHT) at the beginning of every chat session to look up their correspondents' usernames and IP addresses.

One problem with traditional public-key encryption is that it's theoretically possible to acquire a user's private encryption key and use that to read all of his or her saved messages. To counteract this possibility, BitTorrent Chat will also assign users temporary encryption keys for each new conversation. Once the conversation is over, the key is gone forever, leaving would-be spies out-of-luck.

The BitTorrent engineers also addressed a possible concern about using a DHT to store encryption keys and IP addresses instead of a traditional server. In theory, allowing all users to access the DHT would share a user's IP address with the whole network.

"We have updated our DHT protocol to support encryption," the post explained. "The new DHT protocol enables users to find each other securely and privately."

Although that's all the information available for now, expect more to surface as the alpha progresses.

There's no way to say for certain whether BitTorrent Chat will actually be as private and secure as the company claims, but the technology behind the program is solid. If you're the type who uses BitTorrent already, this could be the ideal way to talk about the cool files you picked up.

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