Patent ID: 7568223

Claim:
A secure IP telephony system, the system comprising: a signaling controller within an IP telephony network and in communication with at least one Cable Telephony Adapter (CTA), and configured to perform call set up and tear down and to generate a symmetric sub-key in response to a request from the at least one CTA, the request including a signaling controller ticket; wherein the signaling controller ticket comprises a signaling controller session key, an identity of the at least one CTA, and an identity of the signaling controller; the signaling controller further configured to distribute the symmetric sub-key to the at least one CTA in response to the signaling controller ticket; and a Key Distribution Center (KDC) within the IP telephony network and coupled to the signaling controller, and configured to generate and distribute the signaling controller ticket and said signaling controller session key to the at least one CTA using public key encryption, wherein said at least one CTA generates an additional symmetric key specific for a given call based on the symmetric sub-key provided by the signaling controller.