Tracing unauthorized use of secure modules

A tracing system for tracing rogue secure modules in a population of secure modules, said secure modules being configured to receive scrambled data originating from a conditional access system and wherein said rogue secure modules are configured for unauthorized provisioning of control words to a control word sharing network, comprising:

• an event generator for initiating a predetermined number of tracing experiments on a population of secure modules and identifying on the basis of tracing data generated by said predetermined number of tracing experiments said one or more rogue secure modules;
• and, for instructing a conditional access data transmitter in the conditional access system to sent event messages to said population of secure modules wherein event information in said tracing event message is used to select at least part of said secure modules in said population to generate a tracing event;
• at least one tracing event detector configured for receiving said at least one tracing event message;
• and, in response the reception of said at least one tracing event message, monitoring for a predetermined time the presence of at least one tracing event in said control word sharing network;
• and, for storing tracing data in an event database, said tracing data comprising said event information and event trigger information indicating whether or not a tracing event is detected.