On Mon, 10 Feb 2003, Matthew Byng-Maddick wrote:
>On Sun, Feb 09, 2003 at 11:43:55PM -0500, Donald Eastlake 3rd wrote: >> been that you either throw away the first 256 bytes of stream key output >> or use a different key on every message. WEP does neither. TKIP, the new > >You NEVER, EVER, re-use the key for a stream cipher, if you do, you might >as well just give up. By re-using the key, I can get >plaintext (combinator) plaintext, which is easier to solve than >plaintext (combinator) cipherstream. > >It's one of those things, like re-using a pad. Actually, it is re-using a pad, exactly. It's just a pseudorandom pad (stream cipher) instead of a one-time pad. And while WEP had problems, it didn't have that particular problem. New messages with the "same" key would use a later chunk of the cipherstream pad under WEP. Bear --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]