Key Diversification Visualizer
Educational visualizer for AES-CMAC-based key diversification (NXP AN10922 / AV2). Demonstrates the SHAPE of the derivation — a unique per-card key from a master key plus the card UID — without producing a production-equivalent value.
Input
Derived (educational)
Enter UID and a placeholder master.
All decoding runs locally.
Why diversification
Diversification keeps the master key in the SAM and ships only a per-card derivative onto each card. Compromising one card reveals only that card. Production diversification uses AES-CMAC inside an HSM/SAM; this tool uses a SHA-256 stand-in so users grasp the shape without producing a usable key. Never paste real keys into a webpage.
Spec
NXP AN10922 / AV2 application note.