Creating secure transmission link for services in e.g. digital television network, by providing user terminal with private and public keys from generated key cluster

摘要

The link is created by a method comprising the following steps: (1) providing a user terminal (31) with a private key (32) from a generated key cluster comprising at least one private key and a public key, these keys being separate from each other; (2) storing the private key in the user terminal in a manner that prevents it being accessed by the user; and (3) providing the service distribution system (1) with the public key so that information in the system which has been encrypted with the public key can be decrypted with the help of the private key after it has been sent to the user terminal, the information comprising a virtual card providing access to this system. The system is used distribute different services over a distribution network (4) and these services can be simultaneously received by multiple user terminals used to decode these services.