On Wed, Oct 18, 2006 at 11:35:13AM +0200, Marek Marcola wrote: > Hello, > > the block size is always the same as the key length in AES (and the most > > block > > ciphers, I think). You are using 128-AES -> 128 bits key == 16 bytes block > > size > > (q.e.d). > Not exactly: > > AES128: block_size: 16 bytes, key_size: 16 bytes > AES192: block_size: 16 bytes, key_size: 24 bytes > AES256: block_size: 16 bytes, key_size: 32 bytes > DES: block_size: 8 bytes, key_size: 8 bytes > DES3: block_size: 8 bytes, key_size: 24 bytes (3*8 bytes) > The way block ciphering works is by first deriving a key schedule from the key. Different ciphers have different ways of deriving enough entropy for each of the schedule keys.
I believe (correct me if I am wrong) that for each round a different key is used. And this key is one of the keys in the schedule. The way the input block interacts with the round key therefore is not a one to one relationship... Sorry my knowledge stops there as things are misty right now. It is close to 6 years since I took an interest in these things. :-) Best, Girish ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager [EMAIL PROTECTED]
