Cipher mixer with random number generator Abstract
An encryption device has a random number generator whose output is combined by exclusive-or with plaintext input which has been encrypted by a first block cipher. The combined exclusive-or output is encrypted with a second block cipher mechanism which produces a second enciphered output. The output of the random number generator is also encrypted by a third block cipher mechanism which produces a third enciphered output. The first and second block cipher mechanisms differ from each other. United States Patent 6,351,539 February 26, 2002