Last modified Oct 23, 2000

Explanation of DES terms

The Landau article on DES uses some terms you may not be familiar with:

Bit: A bit is a binary digit, i.e. a 0 or a 1.
XOR: XOR is defined on page 57 of the Cryptology reading. It is the same as addition modulo 2. If you have two strings of 0's and 1's (the same length!) and someone tells you to XOR them, you XOR each digit separately.
E.g. 01110001 XOR 10100011 = 11010010 (I think.)
Permutation: Permutation means the same thing as transposition, as in a transposition cypher. Actually, it is defined at the bottom of page 342 of the Landau DES article.

If you come across any others, please let me know!