DESFire key diversification tool

Derive a diversified AES-128 key per NXP AN10922 and check it against what your reader computes.

Application ID (AID)

3 bytes, e.g. ACCE55.

Reverse AID byte order Feed the AID least-significant byte first (ACCE55 becomes 55CEAC).

Privacy key

16-byte AES source key the diversified key is derived from. It never leaves this request.

UID / Tag ID

7 bytes, the card's tag ID.

System ID

AccessGrid issues a random 3-byte value per pass; clear it to skip.

Enter a privacy key and UID to see the diversified key.

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