| 摘要 |
<p>The invention relates to a method of protecting a content to be distributed to a pool of receiving terminals connected to a content distribution network and each having a specific level of security dependent on the technical security means used, method comprising the following steps: at the sending end, - generating a scrambling key for said content, - transforming said scrambling key by a first calculation module 26 arranged at the head of said content distribution network, - scrambling the content by the transformed key, - transmitting the scrambled content and the scrambling key to the terminals, and, - on receipt of said content and the scrambling key by a terminal, - transforming said scrambling key by a second calculation module arranged in said terminal, - descrambling the content with the transformed scrambling key, method characterized moreover by the steps consisting in, at the sending end, - applying to said scrambling key, by means of said first calculation module, a function F defined as a function of said specific security level, and on receipt, - applying to said scrambling key, by means of said second calculation module, a function F defined as a function of said specific security level.</p> |
