Provided are apparatuses, methods, and user interfaces for requesting access to a program or service, receiving the requested program or service and displaying the requested program or service at a user terminal. In one example, a request for a period of time for access to the program or service is transmitted from a user terminal via a broadcast network. The period of time may be converted to a key decryption count corresponding to the period of time and key interval, the key interval being a period of time separating adjacent key stream messages in a key stream corresponding to a content data stream for the program or service. The encrypted program or service may be decrypted at the user terminal based on the period of access, key interval, and/or key decryption count.