Patent ID: 8660265

Claim:
A method, implemented in a mobile communication device, for generating data for use in at least one of encryption, decryption, or authentication of a transmission, the method comprising: (a) performing, with a computing device, a logical operation on an input and a variable to generate a logical output without using any rounds of a full block cipher, wherein the logical output is provided to a partial block cipher, and wherein the logical operation is distinct from the partial block cipher; (b) generating, with the computing device, a cipher output of the partial block cipher by processing the logical output using only a subset of rounds of the full block cipher, wherein the full block cipher includes (i) the subset of rounds and (ii) additional rounds; repeating operation (a) and operation (b) to generate a plurality of cipher outputs, wherein the respective cipher output generated previously in operation (b) is utilized as the respective input the next time operation (a) is performed; incrementing the variable prior to each time operation (a) is repeated; and using the plurality of cipher outputs for at least one of encryption, decryption, or authentication of the transmission.