Increasing key space at little extra cost in RFID authentications

Traditional authentication and key establishment protocols utilize nonce parameters as a means for message freshness, recent aliveness, and key derivation. Improving identity verification, increasing key space, or making secret updates more complex through nonces are not goals. Generating random numbers as nonces and not making the most out of them can be considered as a loss in resource stricken radio frequency identification (RFID) tags. By increasing the shared secrets slightly, a new functionality for the nonces is introduced, which makes the authentication and key establishment protocols of RFID systems more secure, in general. The proposed method contributes to the security of communication channels by increasing the key space. Attaining better security, with just a slight increase in the shared secrets and the already generated nonces, is beneficial compared to the existing costly, resource-demanding security primitives.