An optical storage medium (20) comprises a first data layer (21), for example a Blu-ray (BD) data layer. In addition, the optical storage medium (20) comprises a second data layer (23), for example a DVD data layer. The second data layer (23) is bonded to a substrate (25) using a third layer (27). The third layer (27) comprises an adhesive layer combined with a reactive layer. A reactive agent contained in the reactive layer acts to provide a limited lifetime to the data contained in the second layer (23). The second data layer (23) (i.e. having a limited lifetime) contains access data for controlling access to at least some of the data contained on the first data layer (21). In this way, access to a BD layer can be controlled by a separate DVD layer having a limited lifetime.