Timothy C. May wrote: | With some weak ciphers, this might work. I think Schneier makes some | comments about who's looked at this. But weak ciphers are not too | interesting. At the most recent Crypto, someone mentioned that FEAL is useful because just about any new attack you can think of works well against it. I think it was Susan Langford. Weak systems are thus useful for research and training purposes. I suspect Tim is on the money with a genetic algorithim having a flat `fitness landscape,' but there may be something that a human misses which an evolved algorithim finds. Also, it may be possible to evolve something against a reduced round version of a cipher (using a training space that is not flat) that will still work better than brute force against a full system. If you have cycles to spare, it might be an interesting avenue of research. Adam -- "It is seldom that liberty of any kind is lost all at once." -Hume