Patent ID: 7827413

Claim:
A method for extracting a private datum from an integrated circuit taking part in an authentication procedure performed by an external device using the private datum, comprising steps of: generating the private datum on request, using at least one electrical parameter obtained from a physical parameter network; and making the private datum ephemeral, wherein upon each generation of the private datum, a lifetime of the private datum is initialized and the private datum is deleted from at least one first storage element containing the private datum, at the end of the lifetime, and wherein the physical parameter network is programmed, at least partially, by a binary word provided by a storage element and specific to the integrated circuit, wherein the physical parameter network comprises a plurality of electrical paths and the private datum comprises a plurality of bits, wherein each electrical path from the plurality of electrical paths provides a respective bit from the plurality of bits, wherein at least one electrical path from the plurality of electrical paths includes a delay element, and wherein the delay element provides a delay different from a delay provided by at least one another electrical path from the plurality of electrical paths.