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US 2011/0033045 A1Published application
Countermeasure method for protecting stored data
AssigneeSTMicroelectronics (Rousset) SAS
InventorFrédéric Bancel
Life of this patent
Estimating the term…
Abstract
A method of read or write access by an electronic component of data, including generating a first secret key for a first data of an ordered list of data to access, and for each data of the list, following the first data, generating a distinct secret key by means of a deterministic function applied to a secret key generated for a previous data of the list, and the application of a cryptographic operation to each data to be read or to be written of the list, carried out by using the secret key generated for the data.
Claims27
A method, comprising:
- generating a first secret key for a first data of an ordered list of data read or to be written by an electronic device;
- for each data of the list, following the first data, generating a distinct secret key based on a deterministic function;
- applying a cryptographic operation to each data read or to be written of the list based on the secret key generated for the data, wherein the deterministic function is applied to a secret key generated for a previous data of the list and at least one of:
- the previous data;
- and
- a result of application of the cryptographic operation to the previous data;
- comparing a result of application of the cryptographic operation to a last data of the ordered list to a reference data;
- and
- selectively causing the electronic device to enter an error state based on the comparison.
6 more elements
An electronic device, comprising:
- a key generator configured to:
- generate a first secret key for a first data of an ordered list of data read or to be written by the electronic device;
- and
- for each data of the list, following the first data, generate a distinct secret key based on a deterministic function;
- a cryptographic unit coupled to the key generator and configured to apply a cryptographic operation to each data read or to be written of the list based on the secret key generated for the data, wherein the deterministic function is applied to a secret key generated for a previous data of the list and at least one of:
- the previous data;
- and
- a result of application of the cryptographic operation to the previous data;
- and
- a comparator configured to:
- compare a result of application of the cryptographic operation to a last data of the ordered list to a reference data;
- and
- control a state of the electronic device based on the comparison.
10 more elements
A system, comprising:
- a processor;
- a memory;
- a countermeasure device coupled between the processor and the memory, the countermeasure device comprising:
- a key generator configured to:
- generate a first secret key for a first data of an ordered list of data to be transferred between the processor and the memory;
- and
- for each data of the list, following the first data, generate a distinct secret key based on a deterministic function;
- and
- a cryptographic unit coupled to the key generator and configured to apply a cryptographic operation to each data of the list based on the secret key generated for the data, wherein the deterministic function is applied to a secret key generated for a previous data of the list and at least one of:
- the previous data;
- and
- a result of application of the cryptographic operation to the previous data;
- and
- an error detector configured to:
- compare a result of application of the cryptographic operation to a last data of the ordered list to a reference data;
- and
- control a state of the system based on the comparison.
14 more elements
A device, comprising:
- means for generating a first secret key for a first data of an ordered list of data, and, for each data of the list following the first data, generating a distinct secret key based on a deterministic function;
- means for applying a cryptographic operation to each data read or to be written of the list based on the secret key generated for the data, wherein the deterministic function is applied to a secret key generated for a previous data of the list and at least one of:
- the previous data;
- and
- a result of application of the cryptographic operation to the previous data;
- and
- means for causing the device to enter an error state when a result of application of the cryptographic operation to a last data of the ordered list differs from a reference data.
4 more elements
Dependencies are inferred from the claim text.