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The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:18:02
David Wagner (daw@CS.Berkeley.EDU)
11 Jan 1999 11:29:19 -0800
In article <19990111124831.A6100@progressive-systems.com>,
Ge' Weijers <ge@Progressive-Systems.Com> wrote:
> You would not be able to use this block cipher in any standard modes,
> unless you have only a short block to encrypt. A 2-byte block cipher in
> CBC mode would show duplicate values in the output after O(sqrt(2^16))
> blocks, i.e. O(256), which is not that much. After that you have to
> change the key. A way out would be to use a pseudo-random function in
> CFB mode.
Surely you mean a pseudo-random function in counter mode?
A PRF in CBC mode will also leak information after about
256 blocks of ciphertext, due to the same effect.
The following archive was created by hippie-mail 7.98617-22 on Sat Apr 10 1999 - 01:18:02