On Wed, 13 Aug 1997, Ray Arachelian wrote:
On Wed, 13 Aug 1997 nospam-seesignature@ceddec.com wrote:
In terms of padding does it matter WHERE I put the padding info? Is it better to put random stuff in the front or at the end? The reason I ask, say that you're going to encrypt an N byte block where N is bigger than your block cypher's key size?
If my intution is correct, and you have the same data encrypted with many keys (even RSA) but have the padding at the end, the 1st block would still be breakable. I suppose putting the data at the end would also result in the same kind of problem, though it might be a bit harder to attack than putting the data 1st...
Would it not make sense to scatter the random padding throughout the block? How is this normally done? Front? Back? Middle? Scattered?
The location does not matter. The standard RSA libs place the padding at the front - it is one of those PKCS specifications. You would simply need to break the conventional key down to a few bytes smaller than the modulus size, so each would be padded with a few random bytes. --- reply to tzeruch - at - ceddec - dot - com ---