Protection of broadcast content with key distribution using telecommunications network

摘要

A method is disclosed for controlling use, by a user terminal 1 registered with a telecommunications network 3, of content broadcast by broadcasting means 7 and encrypted by a first key TEK. The first key TEK, encrypted by a second key SEK_pub, is provided to the broadcast platform 7 for broadcast to the terminal 1 with the encrypted content. A key SEK_priv corresponding to the second key SEK_pub is selectively provided to the user terminal 1 by point to point communication between the telecommunications network 3 and the user terminal 1. This second key SEK_pub and the corresponding key SEK_priv are different but related keys, and the corresponding key SEK_priv enables decryption of the content. In the embodiment the second key and the corresponding key are the public key and private key, respectively, of a public/private key pair.