A method to enforce watermarking instructions by a security module in a receiving device, comprising the steps of receiving a security message by—a security module, comprising at least a content key, watermark instructions and security message signature, said watermark instruction activates or deactivates a watermarking module, decrypting—a security message with a transmission key, verifying—a security message signature, and in case of successful verification, reading a watermarking data from the watermarking module, verifying the authenticity of the watermarking data, and in case of successful verification, transmitting the watermark instructions to the watermark module and the content key to a descrambling module.