Patent ID: 8085937

Claim:
A method of securing a call, the method comprising: using a computerized system, determining whether a first endpoint or a first authentication device associated with a first user supports session key functionality; receiving, at a first gatekeeper from the first endpoint, a Voice-over Internet Protocol (“VoIP”) call request, the VoIP call request comprising a first digital certificate containing a first public key; using a computerized system, authenticating the first digital certificate; if authentication succeeds, using a computerized system, obtaining the first public key from the digital certificate; using a computerized system, assessing access privileges of the first user's right to participate in the call; if the first user has sufficient access privileges to participate in the call, using a computerized system, generating a session key at the first gatekeeper; using a computerized system, encrypting the session key with the first public key to yield a first encrypted session key; using a computerized system, determining whether the first gatekeeper can process the call request by determining whether the first gatekeeper supports communication with a second user associated with a second endpoint; if the first gatekeeper does not support communication with the second user associated with the second endpoint, using a computerized system: multicasting a location request to one or more known gatekeepers, the one or more gatekeepers comprising a second gatekeeper, the second gatekeeper supporting communication with the second user associated with the second endpoint, receiving a third encrypted session key from the second gatekeeper, the second gatekeeper encrypting a second session key with a public key associated with the first gatekeeper to yield the third encrypted session key, decrypting the third encrypted session key at the first gatekeeper, and encrypting the second session key at the first gatekeeper with a second public key to yield a second encrypted session key if the first gatekeeper does support communication with the second user associated with the second endpoint, using a computerized system, encrypting the session key with the second public key to yield a second encrypted session key; using a computerized system, transmitting the first encrypted session key from the first gatekeeper to a first endpoint; and using a computerized system, transmitting the second encrypted session key from the first gatekeeper to a second endpoint, wherein the first gatekeeper is at a location other than a location of the first endpoint and the second endpoint, and the session key is operable to encrypt a VoIP call between the first endpoint and the second endpoint.