Patent ID: 9602273
Date: 2017-03-21
CPC Classifications: H04L

Claim:
1. A non-transitory machine-readable storage medium encoded with instructions for execution by a keyed cryptographic operation by a cryptographic system mapping an input message to an output message including a first and a second round, wherein the cryptographic operation includes a key scheduling method that produces round keys based upon the encryption key, comprising: instructions for receiving a first input by the first round; instructions for receiving a second input by the first round; instructions for outputting the second input as a third input to the second round; instructions for performing a first cryptographic operation on the second input using a first static round key to produce a first cryptographic output; instructions for combining the first input, the first cryptographic output, and a second encoded dynamic round key to produce a fourth input to the second round, wherein the second encoded dynamic round key is produced by inputting an encoded dynamic encryption key into the key scheduling method; instructions for receiving the third input by the second round; instructions for receiving a fourth input by the second round; instructions for outputting the fourth input as a fifth input to a third round; instructions for performing a second cryptographic operation on the fourth input using a second static round key to produce a second cryptographic output; and instructions for combining the third input, the second cryptographic output, and a third encoded dynamic round key to produce a sixth input to the third round, wherein the third encoded dynamic round key is produced by inputting an encoded dynamic encryption key into the key scheduling method.