Tuesday, December 19, 2006

CPS2 notes, part 4

I have to stress that there is NO progress being made in breaking the encryption. The things I am showing in these notes have been known for over a year and haven't lead to any breakthrough. Hopefully, a public discussion of these properties could generate some valuable feedback.

There also isn't any kind of competition against the people that are attacking the CPS2 encryption in hardware. On the contrary, I think that the hardware path will be the only way to gather more information about the algorithm.

In these notes I have shown several properties that are always true, regardless of the key. This means that they are properties of the algorithm itself, and therefore are hardcoded in hardware. For example, there almost surely are fixed substitution boxes which could be extracted from the custom CPU.

If an algorithm is reconstructed by studying the CPU, we can also test it against the known properties, regardless of the key. If it doesn't match, then the algorithm isn't right. Once an algorithm fitting the properties is found, we can start looking for the key.

1 comment:

Thierry said...

JUst wanted to let you know that even if no one makes a comment EVERYONE is interestted in any progress on CPS2 encryption ,)

If some brute force is needeed at a certain point i'll have plenty of server machine ready for it ,)

Good luck