KEY DELIVERY METHOD AND APPARATUS IN A COMMUNICATIONS SYSTEM

摘要

A method of facilitating access by a user terminal to broadcast and/or multicast data which is encrypted and sent to the user terminal from a communication network, the method comprising: sending an encrypted service key from an access server of the communication network to the user terminal, and passing the encrypted service key to a secure module of the user terminal, the secure module having access to a decryption key for decrypting the encrypted service key but this decryption key being inaccessible to other functions of the user terminal; generating an acknowledgement of receipt of the service key at said secure module, and sending the acknowledgement from the user equipment to the access server; authenticating the receipt at the access server and sending a return acknowledgement from the access server to the user terminal, and passing the return acknowledgement to the secure module; and authenticating the return acknowledgement at the secure module, and subsequently making the decrypted service key available to the user terminal, the service key making possible directly or indirectly the decryption of broadcast and/or multicast data.