The invention relates to the field of security of cryptographic systems. More specifically, it relates to a method for recovering secret data, e.g. a secret, key of a cryptographic device, i.e. to a method of “attacking” the cryptographic device to gain access to concealed information. The invention also relates to a method for evaluating the security of a cryptographic system, i.e. its resistance to attacks aiming at gaining access to its key, or more generally to a secret information contained within said system.