Patent ID: 7992193

Claim:
A method for securing authentication, authorization and accounting (AAA) protocol messages, the method comprising the computer-implemented steps of: at a network device that acts as an AAA client and authenticates itself in a network in communication with an AAA server, receiving and storing an encryption key, a device identifier value, and verification data, wherein the verification data comprises in part a copy of the encryption key and the device identifier value that have been encrypted using a private key of the AAA server; the network device generating a shared secret by applying a computational function to the encryption key and the device identifier value; the network device generating, based on the shared secret, a first message integrity check value for an AAA message; the network device sending the AAA message, the first message integrity check value, and the verification data to the AAA server; at the AAA server, decrypting the verification data using the private key; the AAA server extracting the encryption key and the device identifier value from the verification data; the AAA server generating the same shared secret by applying the computational function to the encryption key and the device identifier value; the AAA server generating, based on the shared secret, a second message integrity check value for the AAA message; and the AAA server further processing the AAA message only when the first message integrity check value matches the second message integrity check value, wherein the shared secret is independently generated at each of the network device and the AAA server.