A device comprises a data storage media storing data content and a digital signature. At least a portion of the digital signature is encrypted on the data storage media. The device also includes a removable control circuitry including a unique key. If the unique key corresponds to the encrypted portion of the digital signature, the removable control circuitry allows access to the data content. If the unique key does not correspond to the encrypted portion of the digital signature, the removable control circuitry prevents access to the data content. Embodiments of the invention may be useful to prevent a user from accessing the data content without the original control circuitry used to write the data content. For example, embodiments of the invention may prevent a user from using a different control circuitry that would readily allow unauthorized copying and distribution of the data content.