Patent ID: 7254233
Filing Date: 2007-08-07
Classification: H04L

Abstract:
1. A method for encrypting and authenticating data as a single entity, comprising: forming a plurality of plaintext blocks from the data; specifying at least one cleartext position; determining a plurality of noise blocks using a nonce value; determining a first plurality of ciphertext blocks and a first plurality of authentication blocks associated with the at least one cleartext position, wherein each of the first plurality of ciphertext blocks is formed by setting a corresponding ciphertext block equal to a corresponding one of the first plurality of plaintext blocks, and each of the first plurality of authentication blocks is formed by: determining a second plurality of ciphertext blocks and a second plurality of authentication blocks not associated with the at least one cleartext position, wherein each of the second plurality of authentication blocks is equal to a corresponding plaintext block, and each of the second plurality of ciphertext blocks is formed by: computing a checksum value based on the first plurality of authentication blocks and second plurality of authentication blocks; computing an authentication tag by combining the checksum value with a noise block, encrypting the combined checksum value and combining the encrypted checksum value with another noise block; and appending the authentication tag to a plurality of transmission blocks, wherein the transmission blocks comprise the first plurality of ciphertext blocks and the second plurality of ciphertext blocks.