Frank Willoughby wrote: | Specifically, the rumors mentioned that there were some questions about the | design of the S-boxes and the possibility that there was a trap door which | would permit the NSA or other gov't agency to quickly obtain the cleartext. This seems not to be true. The design of the S boxes seems to be to foil differential cryptanalysis, where pairs of similar texts are encrypted to find information about the key. | Another rumour was that the French & Israeli intelligence agencies downgraded | the classification of DES to one of the lowest strengths of encryption | algorithms. I wouldn't be suprised; major intelligence agencies are likely to have DES cracking custom hardware. | I have been wondering about these issues off & on for a while & have tried to | do some research on them, but have come up with nothing which would amount to See Schneier's Applied Cryptography, 2nd ed. | Assuming the rumours of the weakness of DES are true, which symmetric | encryption algorithms would you recommend which are substantially more | secure than DES (and which are obtainable from Internet or commercial | sources)? (It doesn't haver to be exportable). I'd use IDEA or 3DES. Again, see Schneier. Adam -- "It is seldom that liberty of any kind is lost all at once." -Hume