| 摘要 |
<p>The invention relates to an apparatus for reading or writing user data (21) stored block-wise in encrypted form on a storage medium (4), the storage of which is divided into blocks, to an apparatus (1) for writing user data (21) block-wise in encrypted form onto a storage medium (4) and to corresponding methods. Since the user data is stored on the storage medium (4) in encrypted form, the apparatus needs to be informed about the encryption key for encrypting the user data before writing it on the storage medium or about the decryption key for decryption of the read user data before outputting it. It is thus proposed according to the present invention that the apparatus for reading comprises: * a command interface (6) for receiving and interpreting a read command (19), said read command including a user data information specifying which user data are to be read, * reading means for reading user data and a related encryption indicator from a block of said storage medium, said encryption indicator indicating if said user data is encrypted or not, said reading means being further adapted for reading a related key data identifier specifying which key data (22) to use for decrypting said user data if said encryption indicator indicates that said user data are encrypted, * decryption means (7, 8, DK) for decrypting said user data using said key data, and * output means (26) for outputting said decrypted user data (16).</p> |
