摘要 |
<p>A computing device-implemented method and system is provided for obtaining an interim masked substitution table value for a given input component in a cryptographic round, such as an AES cryptographic round, using a substitution table and a self-cancelling mask. A mask with a length equal to an entry in the substitution table is provided, wherein the mask comprises a plurality of mask components of equal length such that a bitwise logical inequality operation such as XOR on the mask components equals zero, and the substitution table is masked with this mask. For each of input component, an interim masked substitution table value is obtained from the substitution table thus masked.</p> |