Patent ID: 7328352

Claim:
An apparatus for reading user data comprising files stored block-wise on a storage medium, the storage of which is divided into blocks, and for storing a plurality of keys associated with said files, said apparatus comprising: a command interface for receiving and interpreting a read command, said read command including a user data information specifying which file of said files is to be read, reading means for reading said file and a related encryption indicator from a block of said storage medium, said encryption indicator indicating if said file is encrypted or not, said reading means being further adapted for reading a related key data identifier specifying which key data of said plurality of keys to use for decrypting said file if said encryption indicator indicates that said file is encrypted, wherein the key data identifier is stored next to the block from which the user data are to be read, decryption means for decrypting said user data using said key data, and output means for outputting said decrypted user data.