Patent ID: 8477933
Filing Date: 2013-07-02
Classification: H04L

Abstract:
1. A method for operating a cryptographic device to secure a cryptographic algorithm A executing on the cryptographic device against fault attacks, wherein, given a cryptographic key KO and a message M, the cryptographic algorithm A is set to compute a value A(KO,M), and wherein, given a relationship R between A(KO,M) and A(f(K 0 ),g(M)), where f and g are two bijections, and where f is different from the identity function, the method comprises: a. computing the expected result A(KO,M) of the cryptographic algorithm; b. computing a modified result A(f(K c. checking whether the relationship R between the values A(KO,M) and A(f(K d. detecting an attack if the relationship R is not verified.