Embodiments provide systems and methods for the encryption of data to be stored on media in a library. A method of data encryption may comprise intercepting or monitoring commands sent to a library comprising one or more media stored at secure slots. If in response to a command or commands, media is moved from a secure slot to a drive, data stored on the media by the drive is encrypted, either by an encryption device, the drive or other encryption system, thus allowing encryption based on individual slots or media in a library.