| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technique for multi-casting contents, which can implement utilization control corresponding to user turnover. SOLUTION: The technique comprises: a step, where a key for content to be encrypted or decrypted is delivered to each of information access terminals by using unicast; a step, where an information access terminal acquires the key delivered by using the unicast; a step, where the acquired key is saved in the information access terminal; a step, where content is encrypted by the key saved in the information access terminal; a step, where the encrypted content is delivered to each of the other information access terminals by using multicast; a step, where an information access terminals acquires the encrypted content delivered by using the multicast; a step, where the acquired content is decrypted by a key saved in the information access terminals; and a step, where the decrypted content is played.</p> |
