Fault-to-time converter sensor for low-overhead fault injection attack mitigation

1 . A method for providing fault injection attack mitigation for an integrated circuit, the method comprising:

providing a sampling clock signal to both high voltage threshold (HVT) cells and low voltage threshold (LVT) cells of a fault-to-time converter sensor of an integrated circuit;

providing output of the HVT cells and the LVT cells to an encoder stage of the fault-to-time converter sensor;

storing a first pattern from a delay line associated with the HVT cells via a set of latches;

storing a second pattern from the delay line associated with the LVT cells via the set of latches; and

detecting one or more fault injection attacks with respect to the integrated circuit based on output of the encoder stage.

2 . The method of claim 1 , further comprising:

storing the output of the HVT cells and the LVT cells via the set of latches; and

providing the output of the HVT cells and the LVT cells to the encoder stage via the set of latches.

3 . The method of claim 1 , further comprising:

storing the output of the HVT cells and the LVT cells as cached data via the set of latches; and

providing the cached data to the encoder stage via a set of flip-flops.

4 . The method of claim 1 , wherein detecting the one or more fault injection attacks with respect to the integrated circuit comprises filtering one or more unexpected XOR output values from the output of the HVT cells and the LVT cells.

5 . The method of claim 1 , wherein detecting the one or more fault injection attacks with respect to the integrated circuit comprises identifying a particular sequence of expected XOR output values from the output of the HVT cells and the LVT cells.

6 . The method of claim 1 , wherein the HVT cells are configured to monitor transient changes with respect to the sampling clock signal based on respective high voltage thresholds.

7 . The method of claim 1 , wherein the LVT cells are configured to monitor transient changes with respect to the sampling clock signal based on respective low voltage thresholds.

8 . A fault-to-time converter sensor, comprising:

a set of high voltage threshold (HVT) cells configured to receive a sampling clock signal;

a set of low voltage threshold (LVT) cells configured to receive the sampling clock signal;

an encoder device configured to receive output from the set of HVT cells and the set of LVT cells; and

a processor configured to detect one or more fault injection attacks based on encoded output of the encoder device, wherein:

a first pattern from a delay line associated with the set of HVT cells is stored via a set of latches, and

a second pattern from the delay line associated with the set of LVT cells is stored via the set of latches.

9 . The fault-to-time converter sensor of claim 8 , wherein the set of HVT cells is configured to monitor transient changes with respect to the sampling clock signal based on respective high voltage thresholds.

10 . The fault-to-time converter sensor of claim 8 , wherein the set of LVT cells is configured to monitor transient changes with respect to the sampling clock signal based on respective low voltage thresholds.

11 . The fault-to-time converter sensor of claim 8 , wherein the set of latches is configured to store the output of the set of HVT cells and the set of LVT cells, the output of the set of HVT cells and the set of LVT cells is provided to the encoder device via the set of latches.

12 . The fault-to-time converter sensor of claim 8 , wherein:

the set of latches is configured to store the output of the set of HVT cells and the set of LVT cells as cached data, and

a set of flip-flops is configured to provide the cached data to the encoder device.

13 . The fault-to-time converter sensor of claim 8 , wherein the encoder device is configured to filter one or more unexpected XOR output values from the output of the set of HVT cells and the set of LVT cells.

14 . The fault-to-time converter sensor of claim 8 , wherein the encoder device is configured to identify a particular sequence of expected XOR output values from the output of the set of HVT cells and the set of LVT cells.

15 . An apparatus comprising at least one processor and at least one memory including program code, the at least one memory and the program code configured to, with the at least one processor, cause the apparatus to at least:

provide a sampling clock signal to both high voltage threshold (HVT) cells and low voltage threshold (LVT) cells of a fault-to-time converter sensor of an integrated circuit;

provide output of the HVT cells and the LVT cells to an encoder stage of the fault-to-time converter sensor;

store a first pattern from a delay line associated with the HVT cells via a set of latches;

store a second pattern from the delay line associated with the LVT cells via the set of latches; and

detect one or more fault injection attacks with respect to the integrated circuit based on output of the encoder stage.

16 . The apparatus of claim 15 , wherein the at least one memory and the program code are configured to, with the at least one processor, further cause the apparatus to at least:

store the output of the HVT cells and the LVT cells via the set of latches; and

provide the output of the HVT cells and the LVT cells to the encoder stage via the set of latches.

17 . The apparatus of claim 15 , wherein the at least one memory and the program code are configured to, with the at least one processor, further cause the apparatus to at least:

store the output of the HVT cells and the LVT cells as cached data via the set of latches; and

provide the cached data to the encoder stage via a set of flip-flops.