| 摘要 |
The aim of the present invention is to enforce the watermarking on a content received by a client device, in particular to uncompressed video content. The present invention concerns a method to watermark an uncompressed content received at a client device in a compressed form and encrypted by at least one content key (CW), said content key (CW) as well as watermark instruction forming CAS data, said CAS Data being encrypted by a transmission key and comprising at least one signature to authenticate the CAS Data, said client device comprising A Conditional Access Module (CAS) in charge of the CAS Data, a Descrambler (DSC) having an input to receive the encrypted compressed content and an output to produce an compressed content, a decoder to convert the compressed content into uncompressed content, a Watermark inserter (201) connected to the output of the Decoder, a Secure Activation module (202) connected with the Watermark inserter (201), a Secure Element (SE 200) connected with the Watermark inserter (201) and the Secure Activation module (202),
said method comprising the following steps :
- receiving the CAS Data,
- decrypting by the Conditional Access Module (CAS) the CAS Data with the transmission key,
- verifying the signature of the CAS Data, and if the signature is valid,
- transferring the content key (CW) to the descrambler (103) and the watermark instruction to the Secure Activation module (202),
- transferring the watermark instruction and the unique identifier to the Watermark inserter (201),
- enabling or disabling watermarking by the Watermark inserter (201), the uncompressed content received from the Decoder by watermarking data initialized by the unique identifier. |
