GM 5 Byte Key Calculator

Enter the captured security seed and algorithm byte to work out the 5 byte response the module expects. You can also work backwards from a known key to find the algorithm.

Seed and algorithm

Enter the captured seed and the algorithm byte. The password blob is optional.

Run the calculator to see the 5 byte key, the AES key, and the iteration count.

Find the algorithm

Already know the response key? Enter it with the same seed to find which algorithm byte produced it.

Run a lookup to list every algorithm byte that turns the seed into that key.