Mutual authentication with pseudo random numbers

A verifier device of an authentication system, the verifier device comprising:

• physical layer circuitry;
• and
• processing circuitry operatively coupled to the physical layer circuitry and configured to:
• encode an authentication command for sending to a credential device to authenticate the credential device;
• decode a response communication received from the credential device in response to the authentication command, wherein the response communication includes a first random number determined the credential device using a counter value and updating the counter value for each communication session between the verifier device and the credential device;
• in response to decoding the response communication that includes the first random number, determining the receiver device keying material using the first random number, a second random number and verifier device keying material specific to the verifier device;
• encrypt the first random number, the second random number, and the verifier device keying material for sending to the credential device;
• decrypt encrypted information received from the credential device, wherein the encrypted information includes the first random number, the second random number, and the receiver device keying material according to a script included in the verifier device, wherein the receiver device keying material is produced using a static encryption key specific to the credential device and the first random number and includes a third random number predictable by the verifier device;
• and
• calculate a session encryption key using the static encryption key, the verifier device keying material and the receiver device keying material.

A receiver device of an authentication system, the receiver device comprising:

• physical layer circuitry;
• and
• processing circuitry operatively coupled to the physical layer circuitry and configured to:
• decode an authentication command received from a verifier device for authenticating the receiver device;
• encode a response for sending to the verifier device in response to the authentication command, wherein the response includes a first random number determined by the receiver device in response to the authentication command using a counter value and by updating the counter value for each communication session between the verifier device and the receiver device;
• determine receiver device keying material using a static encryption key specific to the receiver device and the first random number;
• decrypt encrypted information received from the verifier device, wherein the encrypted information includes the first random number, the second random number, and verifier device keying material specific to the verifier device;
• encrypt the first random number, the second random number and the receiver device keying material for sending to the verifier device according to a script included in the receiver device, wherein the receiver device keying material includes a third random number predictable by the verifier device using the first random number, the second random number and the verifier device keying material specific to the verifier device;
• and
• calculate a session encryption key using the static encryption key, the verifier device keying material and the receiver device keying material.