METHODS FOR GENERATING VARIABLE S-BOXES FROM ARBITRARY KEYS OF ARBITRARY LENGTH

摘要

A system for generating variable substitution boxes from arbitrary keys for use in a block cipher system utilizes an initial set of linearly independent numbers (13) to generate substitution tables (15). The initial set of linearly independent numbers (13) is modulated with the bits of an arbitrary key through operations that result in final sets of linearly independent numbers to form the substitution tables (15). The system also includes an implementation which allows for rapid key changes for the crypto system by only generating portions of the substitution tables as needed for specific blocks of input data to be encrypted or decrypted.