Unchangeable physical unclonable function in non-volatile memory
AssigneeMacronix International Co., Ltd.
InventorsChun-Hsiung Hung, Chin-Hung Chang
Life of this patent
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Abstract
A device which can be implemented on a single packaged integrated circuit or a multichip module comprises a plurality of non-volatile memory cells, and logic to use a physical unclonable function to produce a key and to store the key in a set of non-volatile memory cells in the plurality of non-volatile memory cells. The physical unclonable function can use entropy derived from non-volatile memory cells in the plurality of non-volatile memory cells to produce a key. Logic is described to disable changes to data in the set of non-volatile memory cells, and thereby freeze the key after it is stored in the set.
Claims21
A circuit configured for maintaining PUF keys in unchangeable form when needed, comprising:
- a plurality of non-volatile memory cells, wherein the plurality of non-volatile memory cells includes an array of memory cells with peripheral circuits for access to the array;
- logic to use a physical unclonable function to produce a key, and to store the key in a set of non-volatile memory cells in the plurality of non-volatile memory cells;
- and
- logic to disable changes to data in the set of non-volatile memory cells after the key is stored in the set, wherein the peripheral circuits have a first state in which access to the set of non-volatile memory cells to write the key is enabled, and a second state in which access to the set of non-volatile memory cells to write is disabled while access to other non-volatile memory cells in the array to write is enabled, and wherein the logic to disable changes to data in the set of non-volatile memory cells includes an indicator to set the first state or the second state.
A method for operating a circuit configured for maintaining PUF keys in unchangeable form when needed, and including a plurality of non-volatile memory cells, wherein the plurality of non-volatile memory cells includes an array of non-volatile memory cells with peripheral circuits for access to the array, comprising:
- executing a physical unclonable function to generate a key;
- storing the key in a set of non-volatile memory cells;
- and
- after storing the key, disabling changes to data stored in the set of non-volatile memory cells, wherein the peripheral circuits have a first state in which access to the set of non-volatile memory cells to write the key is enabled, and a second state in which access to the set of non-volatile memory cells to write is disabled while access to other non-volatile memory cells in the array to write is enabled, and wherein disabling changes to data stored in the set of non-volatile memory cells includes storing an indicator to set the first state or the second state.
Dependencies are inferred from the claim text.