Reference no: EM132177342

A variation of the following biometric authentication protocol was experimentally tested several years ago at immigration checkpoints in major U.S. airports.

A user registers in person by showing his credentials (e.g., passport and visa) to the registration authority and giving his fingerprint (a "palmprint" was actually used).

The registration authority then issues to the user a tamper-resistant smartcard that stores the reference fingerprint vector and can execute the matching algorithm. The checkpoint is equipped with a tamper-resistant admission device that contains a fingerprint reader and a smartcard reader.

The user inserts his smartcard and provides his fingerprint to the device, which forwards it to the smartcard. The smartcard executes the comparison algorithms and outputs the result ("match" or "not match") to the device, which admits or rejects the user accordingly.

Clearly, an attacker can defeat this scheme by programming a smartcard that always outputs "match." Show how to modify the scheme to make it more secure. The admission device needs to make sure that it is interacting with a valid smartcard issued by the registration authority.

You can assume that the smartcard can perform cryptographic computations. The attacker can program smartcards and is allowed to have an input-output interaction with a valid smartcard but cannot obtain the data stored inside it.