IC device authentication using energy characterization

1. A method comprising:

receiving a first quiescent current (QC) from a device while the device is subject to a first voltage;

receiving a second QC from the device while the device is subject to a second voltage;

determining one or more variability values, comprising one or more r-squared values, based at least in part on:

a comparison of the first QC and an expected QC associated with the first voltage, and

a comparison of the second QC and an expected QC associated with the second voltage; and

determining, based at least in part on the one or more variability values, that a threshold is not satisfied.

2. The method of claim 1 , further comprising applying the first voltage across a Vcc connection and a GND connection of the device.

3. The method of claim 1 , wherein determining the one or more variability values comprises aggregating:

a first difference associated with the comparison of the first QC and the expected QC associated with the first voltage, and

a second difference associated with the comparison of the second QC and the expected QC associated with the second voltage.

4. The method of claim 1 , wherein determining the one or more variability values comprises:

determining, based on the comparison of the first QC and the expected QC associated with the first voltage, a first variability value of the one or more variability values; and

determining, based on the comparison of the second QC and the expected QC associated with the second voltage, a second variability value of the one or more variability values.

5. The method of claim 1 , further comprising:

applying, while a direct-current voltage is applied to the device, an excitation signal to an input of the device;

detecting, based on the applied direct-current voltage and the applied excitation signal, a tested conducted electromagnetic interference (EMI) value of the device; and

determining, based on a difference between the tested conducted EMI value and an expected conducted EMI value, that a second threshold is not satisfied.

6. The method of claim 5 , further comprising determining that the device is a counterfeit device based on determining that both the threshold and the second threshold are not satisfied.

7. The method of claim 1 , wherein the one or more r-squared values are an indication of variance.

8. A method comprising:

applying, while a direct-current voltage is applied to a first device, an excitation signal to an input of the first device;

detecting, based on the applied direct-current voltage and the applied excitation signal, a tested conducted electromagnetic interference (EMI) value of the first device based on a high frequency signal on a Vcc connection of the first device; and

determining, based on a difference between the tested conducted EMI value and an expected conducted EMI value, that a threshold is not satisfied, wherein the expected conducted EMI value is associated with a second device.

9. The method of claim 8 , wherein the high frequency signal is output from a high pass filter.

10. The method of claim 9 , wherein detecting the tested conducted EMI value comprises performing lossy integration, based on the high frequency signal, to determine the tested conducted EMI value.

11. The method of claim 10 , wherein detecting the tested conducted EMI value comprises performing a squaring operation, based on the high frequency signal, to determine the tested conducted EMI value.

12. The method of claim 8 , further comprising:

determining, based on separate applications of a plurality of different voltages to the first device, a plurality of tested QC values; and

determining, based on comparing the plurality of tested QC values with a plurality of expected QC values associated with the second device, one or more variability values; and

determining, based at least in part on the one or more variability values, that a second threshold is not satisfied.

13. The method of claim 12 , further comprising determining that the first device is a counterfeit device based on determining that both the threshold and the second threshold are not satisfied.

14. The method of claim 8 , further comprising amplifying the high frequency signal.

15. A method comprising:

determining, based on separate applications of a plurality of different voltages to a first circuit, one or more variability values;

determining, based on comparing the one or more variability values with one or more expected values, that a first threshold is not satisfied;

determining a tested conducted electromagnetic interference (EMI) value for the first circuit based on high frequency feedback, on a Vcc connection of the first circuit, from an applied excitation signal; and

determining, based on a difference between the tested conducted EMI value and an expected conducted EMI value, that a second threshold is not satisfied.

16. The method of claim 15 , wherein determining the tested conducted EMI value comprises:

applying a direct-current voltage to the first circuit;

applying, while applying the direct-current voltage, the excitation signal to an input of the first circuit; and

determining, based on the applied direct-current voltage and the applied excitation signal, the tested conducted EMI value.

17. The method of claim 16 , wherein determining the tested conducted EMI value comprises performing lossy integration based on the high frequency feedback.

18. The method of claim 15 , wherein the one or more variability values are responsive to a first voltage across the Vcc connection of the first circuit and a GND connection of the first circuit.

19. The method of claim 15 , wherein the one or more variability values comprise one or more r-squared values, and further comprising:

determining that the first threshold is not satisfied based on the one or more r-squared values.

20. The method of claim 15 , further comprising amplifying the high frequency feedback.