US 9,069,971 B2 · Method for testing the security of an electronic device against an attack, and electronic device implementing countermeasures

Abstract

A method of testing security of an electronic device against a combination of a side-channel attack and a fault-injection attack implemented during a method of cryptographic processing that includes: delivering a message signature based on a secret parameter and implementing a recombination of at least two intermediate values according to the Chinese remainder theorem; and verifying the signature on the basis of at least one public exponent. The method of testing includes: transmitting a plurality of messages to be signed by said electronic device; disturbing each message, including modifying the message by inserting an identical error for each message, before executing a step of determining one of the intermediate values; and analyzing physical measurements, obtained during the step of verifying the signature as a function of the message to be signed, the identical error for each message, and an assumption of a value of part of the secret parameter.

Claims15

Dependent claims

A method for testing the security of an electronic device against a combination of a side-channel attack and a fault-injection attack implemented during an execution, in the electronic device, of a method of cryptographic processing that includes a step of delivering a signature of a message on the basis of at least one secret parameter, said step of delivering a signature implementing a recombination of at least two intermediate values according to the Chinese remainder theorem, and a step of verifying said signature on the basis of at least one public exponent, wherein the method for testing comprises:

a step of transmitting a plurality of messages to be signed by said electronic device;
a step of disturbing each message, comprising a modification of said message by the insertion of an identical error into said message, before executing a step of determining one of the intermediate values to be recombined during the step of delivering a signature of said message;
a step of obtaining physical measurements during said step of verifying said signature;
a step of analyzing said physical measurements as a function of said message to be signed, said identical error, and an assumption of a value of a part of said at least one secret parameter.

1 more element

An electronic device comprising:

means for cryptographic processing comprising means for delivery of a signature of a message on the basis of at least one secret parameter, said means for delivery of a signature further comprising means for recombining at least two intermediate values according to the Chinese remainder theorem, and means for verifying said signature from at least one public exponent;
and
means for confusion implemented during a use of the means for cryptographic processing, said means for confusion preventing establishment of a relationship between a result obtained following a use of the means for verifying, said message, an error introduced into said message when the message is used to establish one of said two intermediate values and a part of at least one secret parameter, said relationship enabling an attack to be made by analysis of measurements of physical parameters sent out by said electronic device.

Dependencies are inferred from the claim text.

Method for testing the security of an electronic device against an attack, and electronic device implementing countermeasures

Life of this patent

Method for testing the security of an electronic device against an attack, and electronic device implementing countermeasures

Life of this patent

Abstract

Claims15