Cipher mechanisms with fencing and balanced block mixing

Abstract

An enhanced cryptographic mechanism employs Latin square derived balanced size-preserving block mixers and strong, practical fencing arrays of substitution mechanisms in combination with each other and with block ciphers. Ciphers are expanded into efficient, larger, stronger versions. Block ciphers, in combination with balanced block mixers and/or with substitution mechanisms, produce cryptographic mechanisms with block sizes that are combinations of the sizes of the block ciphers. Ciphers using large data blocks can reduce data expansion to levels normally consistent with small blocks. Different sized enhanced cryptographic mechanisms are used in a multiple-size cryptographic mechanism to minimize wasted block space in a ciphered message. The cryptographic mechanism provides at least three layers of processing. In one embodiment a message passes through a fencing array of substitution mechanisms, balanced block mixers, multiple block ciphers, balanced block mixers, and another fencing array of substitution mechanisms, for encryption and decryption, yet still ciphers at a rate near that of the block ciphers alone.