Patent ID: 8045712

Claim:
A method of ciphering by an integrated processor of data to be stored in a memory, comprising applying a ciphering algorithm, which is a function of at least one key specific to the integrated circuit and of an initialization vector, to obtain ciphered data, wherein the initialization vector includes at least an address of storage of the ciphered data in the memory and a differentiation value associated with the address of storage, the differentiation value having a different value on each writing at a same address of storage in the memory, wherein the differentiation value is provided by at least one counter incremented or decremented on each writing at a same address, the ciphering algorithm being a function of the address of storage and the differentiation value, and storing at least the ciphered data and the differentiation value in the memory at the address of storage, only the differentiation value of the initialization vector being stored with the ciphered data in the memory at the address of storage.