Patent ID: 9020148
Filing Date: 2015-04-28
Classification: G06F,G09C,H04L

Abstract:
1. A method for protecting a key to be used by an electronic circuit in an algorithm, comprising acts of: submitting the key to a first function taking a selection value into account; storing at least one portion of a first result of applying the first function to the key in at least two registers each having a same size as the key, wherein the at least one portion of the first result comprises more bits than the key; when the algorithm issues a call for the key, reading contents of said registers and submitting the contents to a second function, wherein the second function is a combination function that corresponds to the first function, such that a second result of applying the second function to the contents of the registers corresponds to the key submitted to the first function; and using the second result of applying the second function to the contents of the registers to provide a response to the algorithm's call for the key, wherein the second function takes into account all or part of the contents of the registers.