US Patent 8467526 Key evolution method and system of block ciphering

A system and associated method for block ciphering. The method generates a key that is specific to a text block being encrypted and later being decrypted. The text block is encrypted by a block cipher encryption with the key. The encrypted text block is decrypted by a block cipher decryption with the key back to the text block. Altering a single bit in either the encrypted text block or the key results in unsuccessful decryption such that a decrypted text block is completely different from the before encryption.