A system (50) is used for identifying a content item. The system (50) receives a received first identifier (101) of the content item, the received first identifier being based on at least part of a baseband level representation of the content item; a received second identifier (102) of the content item, the received second identifier being based on at least part of an encoded representation (103) of the content item; and the at least part of the encoded representation (103) of the content item. The system comprises a second identifier generator (53) for generating a generated second identifier based on the at least part of the encoded representation (103) of the content item; and a validation unit (54) for validating the received first identifier as a valid first identifier of the content item if the generated second identifier matches the received second identifier.