Method of providing rights data objects

A method is described of providing rights data objects for issuing to a device having access to encrypted content belonging to one of a plurality of events and provided with an indication of a location from which the rights data object may be requested and event information uniquely associated with the event. The device may include an agent function for providing a request to a device issuing rights data objects from the indicated location and data representative of the event information. The method may include receiving the request and data representative of the event information, generating a rights data object, including event key information enabling the content data belonging to the event uniquely associated with the event information to be decrypted, and is characterised by generating the event key information using a cryptographic function that operates on at least a part of the event information.