Method and system for providing copy-protection on a storage medium and storage medium for use in such a system
View Patent ↗In a method for providing copy-protection services on a storage medium (for instance a solid state memory module), the data are arranged in sectors to which a field (S4T) is associated, where said field contains a random value R i which is changed randomly when writing data to said sector. By encrypting the data stored on the medium using a key which depends critically on said random numbers, bit-by-bit copies (apart from said random numbers, which can not be deterministically changed by an application) to a second storage medium or recopies from some intermediate storage medium, can not be decrypted because the values of said random numbers will have changed, thus preventing unauthorized duplication and replay attacks.
1. A method for providing copy-protection services on a data storage medium, wherein stored data is arranged in sectors, a tagging part being associated with each sector, where the tagging part of said sector comprises a field (S4T) that stores a value R i which is randomly changed with each write access to said sector, said field being read-only for external access, and the stored data being stored in encrypted form on said data storage medium with an encryption key that is at least in part derived from values of at least some of said fields (S4T).
2. The method as claimed in claim 1 , wherein the data storage medium is a removable memory module.
3. The method as claimed in claim 1 , wherein the encryption key is derived from the values of said S4T fields associated with sectors in which rights and/or usage information is stored.
4. The method as claimed in claim 3 , wherein the encryption key is in addition derived from values of said S4T fields associated with sectors in which content is stored.
5. A System arranged for implementing a method as claimed in claim 1 comprising a controller unit for choosing the values at random.
6. A Player for playing from a data storage unit prepared according to a method as claimed in claim 1 .
7. A Data storage medium prepared according to a method as claimed in claim 1 comprising a controller unit for choosing the random values.
8. The method according to claim 1 , wherein each sector is organized as a 512 byte sector.
9. The method according to claim 1 , wherein the tagging part associated with each sector is 16 bytes.
10. The method according to claim 2 , wherein the memory module is a flash memory module.
11. The method according to claim 1 , wherein said tagging part comprises at least one of, (a) a bad block flag, (b) a usage count, and (c) error correction information.