1. A method of activating a feature in a conditional access system comprising: receiving a feature authorization message (FAM) comprising a rule for activating a feature of the conditional access system based on a status of one or more attributes of a conditional access module (CAM), said rule specifying test data and status assessment data; providing said test data to said CAM, and receiving output data dependent on said test data and said one or more attributes of said CAM; assessing the status of said one or more attributes based on said output data and said status assessment data; and setting the ability to use said feature based on said status.