Over the past months more BitTorrent users noticed that their ISP is killing all BitTorrent traffic . ISP's like Rogers are using bit-shaping applications to throttle the traffic that is generated by BitTorrent. But, at the same time two of the most popular BitTorrent clients are working together to implement header and message stream encryption in order to take out these traffic shapers.

Currently both Azureus and uTorrent included this new form of encryption (specs) in their latest Beta’s. The fact that these two clients are actively working together to implement this new feature is promising and will make this form of encryption the new standard since the users of these two clients cover the majority of all BitTorrent users.

There are two “encryption modes” available.

The 2 different payload encryption methods plaintext transmission and RC4 provide a different degree of protocol obfuscation, security and speed. Where the plaintext mode only provides basic anti-shaping obscurity, no security and low CPU usage the RC4 encryption obfuscates the entire stream and not only the header and adds some cryptographic security at the price of spent CPU cycles.

The question now is.. Does it work? and how effective is it? If it works it will definitely offer a great solution to all BitTorrent users who suffer from traffic shaping ISP’s.

Bram Cohen, the creator of the BitTorrent protocol reacted quite negatively on these new developments. He questions the need for encryption since only a few ISP’s are actively shaping traffic. Among other things he also fears incompatibility between clients and increased cpu usage. Although these arguments can be countered quite easily, developers should keep them in mind.

But the fact is, if this new encryption method is launched successfully it will be a huge step forward for the BitTorrent community.