Transaction MAC Field Visualizer
Visualise the DESFire EV2/EV3 Transaction MAC field: 4-byte counter (TMC) followed by 8-byte MAC value (TMV). Tamper-evident transaction logging in closed-loop ticketing systems.
Input
Decoded
Paste TMAC field bytes.
All decoding runs locally.
About Transaction MAC
DESFire EV2 introduced Transaction MAC files: every successful CommitTransaction increments TMC and produces a fresh CMAC over the transaction state. The backend reconciles its own TMC counter against the card to detect replays, gaps, or tampering.
Spec
NXP DESFire EV2/EV3 datasheet.