| 摘要 |
<p>The invention concerns a method and a device for guaranteeing the integrity and authenticity of data transmitted between a management centre and one or several receiver units, wherein each receiver unit comprises a decoder (IRD) and a security unit (SC) and means for communicating (NET, REC) with the management centre. The method consists in calculating a control information (Hx) representing the result of a function said to be unidirectional and collision-free, performed on all or part of the transmitted data and in transmitting the result to the management centre for verification. The centre will be able to inform the decoder concerning the authenticity of the data by return channels or by the main channel.</p> |
