ChipShouter Calibration

Embedded Security Glitching
1

Hello,

I have tested multiple ChipShouters and, each time, followed the calibration instructions on pages 41–42 of the manual. In most cases, I have been able to measure at least the recommended 350 V at the maximum pulse amplitude.

However, I recently tested a ChipShouter that reached only about 250 V at the maximum pulse amplitude during calibration. I used the same oscilloscope model as in another setup and double-checked that all settings were configured correctly.

I then tried to reproduce several fault-injection tests on this setup, but unfortunately did not obtain any faults. I am currently trying to determine whether the ChipShouter could be the source of the problem.

Is a maximum calibrated pulse amplitude of approximately 250 V within the normal range, or could it indicate that something is not working correctly with the ChipShouter?

For context, the ChipShouter that produced only approximately 250 V is brand new, whereas the units on which I can measure more than 350 V are considerably older. Has there been a recent hardware revision that could explain this difference?

Thank you in advance for any help or information.

Best wishes

2

Hi,

There was a change to the probes that might have caused this. Can you try with the probes that got up to 350V?

Alex

3

Hi Alex,

I found an old probe from an old ChipShouter, one of the ones where the part near the BNC connector is dark blue, and was able to measure 330 V, which is much closer to what I usually measure. I think the ChipShouter is fine.

I didn’t think the probe was the problem because I had tried two different ones of the new kind and both behaved the same. Furthermore, I have used the newer probe type successfully.

Thanks for your quick response.

Best wishes!