Method for protecting a cryptographic module and a device having cryptographic module protection capabilities
First Claim
1. A method for protecting a cryptographic module, the method comprising:
- estimating a functionality of a circuit that is adapted to malfunction when a physical parameter has a first value different from a nominal parameter value at which the cryptographic module functions correctly, the cryptographic module malfunctioning when said physical parameter has a second value different from said nominal parameter value and a difference between said first value and said nominal parameter value being smaller than a difference between said second value and said nominal parameter value, wherein said circuit is provided with a supply voltage of a first level and a clock signal that has a frequency that exceeds a first frequency threshold, wherein the cryptographic module is adapted to malfunction when being provided with a supply voltage of the first level and a clock signal that has a frequency that exceeds a second frequency threshold, wherein the second frequency threshold is higher than the first frequency threshold, wherein the first frequency threshold is higher than a nominal operational frequency of the cryptographic module when provided with a supply voltage of the first level; and
applying a cryptographic module protective measure if estimating that the circuit malfunctions.
31 Assignments
0 Petitions
Accused Products
Abstract
A device and a method for protecting a cryptographic module of which the method includes: estimating a functionality of a circuit that is adapted to malfunction when a physical parameter has a first value different from a nominal parameter value at which the cryptographic module functions correctly. The cryptographic module malfunctions when the physical parameter has a second value different from the nominal parameter value and a difference between the first value and the nominal parameter value being smaller than a difference between the second value and the nominal parameter value. A cryptographic module protective measure is applied if estimating that the circuit malfunctions.
33 Citations
18 Claims
-
1. A method for protecting a cryptographic module, the method comprising:
-
estimating a functionality of a circuit that is adapted to malfunction when a physical parameter has a first value different from a nominal parameter value at which the cryptographic module functions correctly, the cryptographic module malfunctioning when said physical parameter has a second value different from said nominal parameter value and a difference between said first value and said nominal parameter value being smaller than a difference between said second value and said nominal parameter value, wherein said circuit is provided with a supply voltage of a first level and a clock signal that has a frequency that exceeds a first frequency threshold, wherein the cryptographic module is adapted to malfunction when being provided with a supply voltage of the first level and a clock signal that has a frequency that exceeds a second frequency threshold, wherein the second frequency threshold is higher than the first frequency threshold, wherein the first frequency threshold is higher than a nominal operational frequency of the cryptographic module when provided with a supply voltage of the first level; and applying a cryptographic module protective measure if estimating that the circuit malfunctions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A device having cryptographic module protection capabilities, the device comprises:
-
a circuit; a cryptographic module; and a monitor; wherein the circuit malfunctions when a physical parameter has a first value different from a nominal parameter value at which the cryptographic module functions correctly, the cryptographic module malfunctions when said physical parameter has a second value different from said nominal parameter value, a difference between said first value and said nominal parameter value being smaller than a difference between said second value and said nominal parameter value, wherein the circuit malfunctions when being provided with a supply voltage of a first level and a clock signal that has a frequency that exceeds a first frequency threshold, wherein the cryptographic module is adapted to malfunction when being provided with a supply voltage of the first level and a clock signal that has a frequency that exceeds a second frequency threshold, wherein the second frequency threshold is higher than the first frequency threshold, wherein the first frequency threshold is higher than a nominal operational frequency of the cryptographic module when provided with a supply voltage of the first level; wherein the monitor estimates a functionality of the circuit and participates in an appliance of a cryptographic module protective measure if estimating that the circuit malfunctions. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18)
-
Specification