Using Perimeter Detect


Self destruct mode only works after the lock tab has been cut.


Hi again,

I have read this in [Power Quality] topic:

In the event of poor power quality the Zymkey instantaneosly shuts down access to the security API and communication channels and retreats into sleep mode (no sleep mode on Zymkey 4i lite). In sleep mode the Zymkey continues to monitor the quality of the 5V power rail and when conditions have stabilized it reactivates the security API and communicaiton channels.

I have many questions about this:

  • is the power quality you are talking about is ONLY the 5V from the Raspberry, or does it include the coin cell of the zymkey?
  • what happens, in locked mode, if we remove the cell coin: is the zymkey will interpret this like a potential attack and will delete all these keys (if the good flag was set before to cut the PCB) during the next starting ? I mean, is the zymkey able to know when he boots than the coin cell was removed before, or it will juste start normally after.



do you have any answer to give me for my last question?
Thx by advance!

  • Power quality monitors only +5V from the Raspberry Pi.
  • With Zymkey 4, the coin cell removal is not interpretted as an attack, so keys will not be deleted.
  • With Zymkey 5, the coin cell removal can be interpretted as an attack, and the response policy is set by the user prior to locking. Zymkey 5 is available on pre-order here:


ok thx! How the zymkey 5 will “work” to detect a coin cell removal during the next boot?


We do not disclose the details of “how” it works, but it will work :wink: