Splitting S-boxes in a white-box implementation to resist attacks

摘要

A method of performing a keyed cryptographic operation mapping an input message to an output message, wherein the input message comprises m input data and the output message comprises m output data and wherein the cryptographic operation includes at least one round and the cryptographic operation specifies a substitution box for mapping input data into output data, including: transforming each of the m input data into n output data using n split substitution boxes, wherein the n split substitution boxes sum to the specified substitution box; and mixing and combining the m×n output data.