Patent ID: 8090098
Filing Date: 2012-01-03
Classification: H04L

Abstract:
1. A computer implemented method of generating a Message Authentication Code (MAC) by a processor using a stream cipher, comprising the steps of: (a) dividing an input message M into k n-bit message blocks, wherein k is an integer number, wherein each of the respective divided input message blocks have a unique integer number represented by the respective K integer number; (b) encrypting by a processor each of the respective divided input message blocks using a result obtained by exclusive-ORing (XORing) with a different key, wherein the results by XORing each of the divided input message blocks has a different key from any of the other divided input message blocks, wherein each of the different keys is configured with a secret key K wherein in step (b), the respective intermediate values hi are calculated by the following formula: wherein the k n-bit message blocks obtained by dividing the input message M are denoted by m c) XORing the respective intermediate values resulting from step (b); and (d) encrypting, at a key stream generator, the result of step (c) using the secret key K