One powerful application for peer-to-peer systems is in the field of crypto analysis.
Back in 1992 a team of four people started to work on a method to crack a message that is encrypted using RSA with a key length of 129 bits. These people were Derek Atkins, a student from MIT, Michael Graff, a student at Iowa State University, Paul Leyland at Oxford University and Arjen Lenstra, the renowned mathematical expert at Bellcore.
They realized that they needed help in order to have enough computing power to crack the code. To solve this problem, they called on volunteers to run a piece of software on their PC which works on part of the crack, and feeds the results to a central server for further analysis. More than 1600 machines from all continents except Antarctica worked on the problem. The code was cracked after 7 months – revolutionary at the time!
This concept has matured over the years and today can be found in services such as distributed.net. These services however, only use a small fraction of the PC’s available on the Internet….
Imagine the computing power if you bundle code-breaking software with each Kazaa download. The Kazaa client has already been downloaded more than 300 million times since it was launched. At any point in time there are approximately 3 million users on the Kazaa network. In other words there are 3 million PC’s that can be used for ‘real-time’ crypto analysis!
According to United Devices, if you assume that each PC on the Kazaa network is equipped with a 1 Ghz Intel Pentium 3 processor that is on average 50% utilized, the potential computing power of this network is 1500 Teraflops – equivalent to 17361 Sun Fire 15k Servers.
I am no cryptography expert but I think this amount of computing power is sufficient to take ‘a crack’ at some of the modern encryption technologies.