Method for storing a key in a non-volatile memory
AssigneeSTMicroelectronics International N.V.
InventorJawad Benhammadi
Life of this patent
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Abstract
A method is presented for verifying a writing of a key into a non-volatile memory. A first cyclic redundancy code of the key is stored into a register of an interface of the memory. A second cyclic redundancy code is computed on a message formed by the copied key having the first cyclic redundancy code linked thereto. The writing of the key into the non-volatile memory is considered as valid when the second cyclic redundancy code is equivalent to the zero value.
Claims21
A method for verifying a writing of a key into a non-volatile memory, comprising the steps of:
- storing a first precomputed cyclic redundancy code of said key in a register of an interface of said non-volatile memory;
- writing the key into a zone of the non-volatile memory;
- copying the key which was written into said zone into a second register of said interface;
- computing a second cyclic redundancy code on a message formed by the copied key having the first cyclic redundancy code linked thereto;
- and
- considering the writing of the key into said non-volatile memory as valid when the second cyclic redundancy code is equivalent to a zero value.
A method of processing a key with respect to a non-volatile memory of an integrated circuit comprising at least an interface of communication with the outside of the integrated circuit, comprising steps of:
- writing, from outside of the integrated circuit, a key into a second register of an interface of the non-volatile memory;
- writing, from the outside the integrated circuit, a first precomputed cyclic redundancy code into a first register of said interface;
- computing a result of a third cyclic redundancy code on a message formed by the key having the first precomputed cyclic redundancy code linked thereto;
- and
- considering writing of the security key into the second register as valid when the third cyclic redundancy code is equivalent to a zero value.
Dependencies are inferred from the claim text.