Patent ID: 8386767

Claim:
A method for bootstrapping key establishment to exchange encryption keys between a terminal-based client, a bootstrapping server and an application server, all using Session Initiation Protocol (SIP) signaling, the method comprising the steps of: obtaining a Bootstrapping Transaction Identifier (B-TID) using a SIP message; transmitting, from said terminal-based client, a SIP message including said B-TID to a SIP/IP Core Node receiving said SIP message at said SIP/IP core node; routing said SIP message, including said B-TID, to said application server; transmitting, in response to said SIP message and by said application server, an authorization request message which includes said B-TID to a bootstrapping function (BSF) entity; generating, at said BSF entity, a shared key Ks_(ext/int)_NAF value associated with said B-TID; transmitting, from said BSF, said Ks_(ext/int)_NAF value to said application server; transmitting, from said application server, a response message back to said SIP/IP core node; and routing said response message from said SIP/IP core node to said terminal- based client.