Other Directory Sites: SeekWonder | Directory Owners Forum
The following archive was created by hippie-mail 7.98617-22 on Thu May 27 1999 - 23:44:21
Mok-Kong Shen (mok-kong.shen@stud.uni-muenchen.de)
Wed, 07 Apr 1999 09:43:58 +0200
Some recent discussions, if I understood correctly (my apology in case
I didn't), carried the apparent connotation that the Vernam Cipher is
quite different from a stream cipher.
However, on p.21 of the Handbook by Menezes et al. one reads:
1.39 Definition. The Vernam Cipher is a stream cipher defined
on the alphabet A = {0,1}. A binary message m_1,m_2,... m_t
is operated on by a binary key string k_1,k_2,... k_t of the
same length to produce a ciphertext string c_1,c_2,... c_t
where
c_i = m_i (+) k_i 1 <= i <= t
If the key string is randomly chosen and never used again, the
Vernam cipher is called a one-time system or a one-time pad.
Thus (1) the Vernam cipher is a stream cipher, (2) a Vernam cipher
does not necessarily have to do with the one-time pad. In my humble
understanding the majority of present day stream encoding is performed
at the bit level with XOR and is hence Vernam cipher.
M. K. Shen
------------------------------------------------------
M. K. Shen, Postfach 340238, D-80099 Muenchen, Germany (permanent)
http://www.stud.uni-muenchen.de/~mok-kong.shen/ (Updated: 12 Mar 99)
(Origin site of WEAK2-EX, WEAK3-EX and WEAK4-EX, three Wassenaar-conform
algorithms based on the new paradigm Security through Inefficiency.
Containing 2 mathematical problems with rewards totalling US$500.)
The following archive was created by hippie-mail 7.98617-22 on Thu May 27 1999 - 23:44:21