Small and Secure Transponder for Vehicle Keys


The Smartrac AES-TAG is a cryptographic Read/Write Transponder containing the NISTproven public encryption algorithm AES (Advanced Encryption Standard).  


It has been specially developed to fulfil the most extreme requirements in security. The performance optimised implementation is based on 128 bit secret key with multiple authentication methods and security levels.


Due to the protocol concept extremely short timings are selectable in all authentication modes single, mutual and mutual ISO. Random number generation is supported via an embedded TRNG.  


By providing an exceptional EEPROM memory size each kind of application can be served, about 1,8 Kbytes of non-volatile memory is reserved for storing any kind of user information and application data. The transponder also contains a 32 bit identification number as well as multiple configuration and lock-mechanisms. Various protections mechanisms for the user-memory can be configured on customer’s choice and preference. A special increment-counter in ring-buffer-architecture completes the outstanding feature list of this product.  


The AES-TAG transponder works at a 125kHz resonant frequency and is available in a miniature, durable glass rod for easy moulding into vehicle key heads.  


This product offers the same high security algorithm as all AES-Family products so that it is usable across common vehicle platforms and electronics, e.g. AES-TAG could be used in the valet key without incurring the additional cost of the remote key electronics based on TAGMICRO-TX.  



Encrypted Read / Write

Transponder baud rate

4 kBd @ 125 kHz

Transponder Frequency

125 kHz ± 3 kHz

Total Memory

10240 bit



Transponder Coding type


Operating Temperature

-40°C to +85°C


Glass 3,15 x 13,3 mm

Encryption Algorithm

AES single authentication
AES mutual authentication
AES mutual ISO authentication


  • Advanced security features
  • Customer specific configuration
  • Small and flexible solution
  • Durable glass housing