Patent ID: 7983656

Claim:
A non-transitory computer readable storage medium, comprising computer instructions for: providing information associated with an Elliptic Curve Diffie-Hellman (ECDH) cryptosystem to a group of Mobile Stations (MSs) using a base transceiver station; authenticating a first MS of the group of MSs using a first Visitor Location Register (VLR) of a Mobile Switching Center (MSC) and authenticating a second MS of the group of MSs with a second VLR of the MSC; sending a first certificate of the first MS from the first VLR to the second VLR and sending a second certificate of the second MS from the second VLR to the first VLR; and sending the first certificate from the second VLR to the second MS and sending the second certificate from the first VLR to the first MS, wherein data communicated between the first MS and the second MS is encrypted with a secret key computed individually by both the first MS and the second MS from the first certificate and the second certificate, respectively.