COUNTERMEASURES AGAINST POWER ATTACKS FOR THE RANDOMIZATION OF THE EXPONENT

摘要

The invention relates to a method for protecting an electronic device against a side channel attack scrutinizing the physical behavior of the electronic device while it executes a cryptographic algorithm in order to crack the value of a secret parameter used by the cryptographic algorithm. The method comprises computing a randomized parameter to be used in the cryptographic algorithm instead of the secret parameter which protection is sought. After having computed an initial number of randomized parameters based on the secret parameter, the electronic device carries out each subsequent computation of a randomized parameter based on a previously randomized parameter. The invention also relates to the electronic device.