Methods and Apparatus for Authentication and Identity Management Using a Public Key Infrastructure (PKI) in an IP-Based Telephony Environment

Methods and apparatus are provided for user authentication using a Public Key Infrastructure (PKI) in an IP-based telephony environment, such as an IMS network. A user of a user device attempting to access an IP-based telephony network can be authenticated by obtaining one or more private keys of the user from a secure memory associated with the user device; generating an integrity key and a ciphering key; encrypting the integrity key and the ciphering key using a session key; encrypting the session key with a public key of the IP-based telephony network; and providing the encrypted session key, encrypted integrity key and encrypted ciphering key to the IP-based telephony network for authentication. A network-based method is also provided for authenticating a user in an IP-based telephony network.