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US 8,477,933 B2Granted
Cryptographic algorithm fault protections
AssigneeGemalto SA
InventorsDavid Vigilant, Stéphanie Salgado
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AssigneeGemalto SA
InventorsDavid Vigilant, Stéphanie Salgado
Estimating the term…
The invention relates to a method for securing the execution of a cryptographic algorithm A against fault attacks. Given a cryptographic key KO and a message M, the cryptographic algorithm A is set to compute a value A(KO,M). Given a relationship R between A(KO,M) and A(f(K0),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(K0),g(M)), by applying the cryptographic algorithm A on a modified key f(K0) and on a message g(M), c. checking whether the relationship R between the values A(KO,M) and A(f(K0),g(M)) computed in the two preceding steps is verified d. detecting an attack if the relationship R is not verified. The invention also relates to a cryptographic device embodying the above method.
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(K0),g(M)), where f and g are two bijections, and where f is different from the identity function, the method comprises:
The cryptographic device implementing a cryptographic algorithm A, wherein, given a cryptographic key KO and a message M, the cryptographic algorithm A is set to compute a value A(KO,M), given a relationship R between A(KO,M) and A(f(K0),g(M)), where f and g are two bijections, and where f is different from the identity function, the cryptographic device comprises means for:
Dependencies are inferred from the claim text.