Record carrier comprising encryption indication information

Abstract

A record carrier, recording device, read-out device and method is provided which provides a flexible security level to protect user data during transmission over a communication bus, also when the data is recorded on a record carrier such as a recordable optical disc. In accordance with the method, management information comprising encryption indication information indicating that user data stored in an associated sector of a record carrier, such as a recordable optical disk, is to be encrypted by a read-out device before being transmitted over a communication bus.

The invention claimed is: 
     
       1. Record carrier ( 10 ) for storing user data in sectors (S) and management information (M) associated with said sectors (S), and stored in a sector header of each sector, 
 wherein said management information (M) comprises an encryption indication information (M 1 ) comprising a single bit associated with each of said sectors (S), each bit indicating to a read-out device whether at least a part of the user data stored in the associated sector (S) are to be encrypted by the read-out device ( 2 ) before being transmitted over a communication bus ( 6 ), and 
 wherein said management information (M) further comprises an encryption amount information (M3) indicating which parts of each of said sectors (S) are to be encrypted while other parts of each of said sectors (S) remain unencrypted. 
 
     
     
       2. Record carrier as claimed in  claim 1 , wherein said management information (M) is stored in a sector header ( 4 ) or in an additional sub-code channel. 
     
     
       3. Record carrier as claimed in  claim 1 , wherein said management information (M) further comprises an encryption amount information (M 3 ) indicating which part or parts of the user data stored in the associated sector (S) are to be encrypted. 
     
     
       4. Record carrier as claimed in  claim 1 , wherein said management information (M) further comprises an encryption algorithm information (M 4 ) indicating which encryption algorithm is to be used for encryption. 
     
     
       5. Record carrier as claimed in  claim 1 , wherein said management information (M) further comprises a key-hierarchy information (M 5 ) indicating which key-hierarchy is to be used for determination of an encryption key to be used for encryption. 
     
     
       6. Record carrier as claimed in  claim 1 , wherein said management information (M) further comprises a decryption indication information (M 2 ) indicating that the user data stored in the associated sector (S) are to be decrypted by the read-out device ( 2 ) before being encrypted again for transmission over said communication bus ( 6 ). 
     
     
       7. Record carrier as claimed in  claim 6 , wherein a decryption key for decryption of the user data is dependent on at least the encryption indication flag information bit (M 1 ). 
     
     
       8. Read-out device for reading data from a record carrier ( 10 ) storing user data in sectors (S) and management information (M) associated with said sectors (S), wherein said management information (M) comprises an encryption indication information (M 1 ) comprising a single bit associated with each of said sectors (S), each bit (M 1 ) indicating whether at least a part of the user data stored in the associated sector (S) are to be encrypted by a read-out device ( 2 ) before being transmitted over a communication bus ( 6 ), comprising:
 a reading unit ( 21 ) for reading said user data and said management information (M) from said record carrier ( 10 ), 
 a data interpreter ( 23 ) for interpreting said management information (M), 
 an encryption unit ( 24 ) for encrypting user data of sectors (S) for which the associated encryption indication flag information bit (M 1 ) indicates that at least a part of said user data are to be encrypted and an output unit ( 25 ) for outputting said user data and encryption amount information (M3) indicating which parts of each of said sectors (S) are to be encrypted while other parts of each of said sectors (S) remain unencrypted. 
 
     
     
       9. Read-out method for reading data from a record carrier ( 10 ) storing user data in sectors (S) and management information (M) associated with said sectors (S), wherein said management information (M) comprises an encryption indication information (Ml) comprising a single bit associated with each of said sectors (S), each bit (M 1 ) indicating whether the user data stored in the associated sector are to be encrypted by a read-out ( 2 ) device before being transmitted over a communication bus ( 6 ), comprising the steps of: reading said user data and said management information (M) from said record carrier ( 10 ), interpreting said management information (M), encrypting user data of sectors (S) for which the associated encryption indication information (M 1 ) indicates that said user data are to be encrypted and outputting said user data. 
     
     
       10. Recording device for recording data on a record carrier ( 10 ) comprising:
 an input unit ( 27 ) for receiving user data and a command (C) to record said user data in sectors (S) on a record carrier ( 10 ) from a communication bus ( 6 ), 
 a command interpreter ( 26 ) for interpreting said command (C) so as to identify a decryption indication information (C 2 ) included therein indicating which parts of the received user data are encrypted and are to be decrypted before recording on said record carrier ( 10 ), 
 a decryption unit ( 24 ) for decrypting the parts of said user data for which the associated decryption indication information (M 2 ) indicates that they are encrypted and are to be decrypted before recording on said record carrier ( 10 ), and 
 a write unit ( 22 ) for recording said user data in sectors (S) on said record carrier ( 10 ) and 
 a management information (M) associated with said sectors (S) comprising an encryption indication information (M 1 ) comprising a single bit associated with each of said sectors (S), each bit (M 1 ) indicating whether at least a part of the user data stored in sectors (S) associated with said management information (M) are to be encrypted by a read-out ( 2 ) device before transmission over a communication bus ( 6 ), 
 wherein said management information (M) further comprises an encryption amount information (M3) indicating which part or parts of the data stored in the associated sector (S) are to be encrypted while other parts of the associated sector (S) remain unencrypted. 
 
     
     
       11. Recording method for recording data on a record carrier ( 10 ) comprising the steps of: receiving user data and a command (C) to record said user data in sectors (S) on a record carrier ( 10 ) from a communication bus ( 6 ), interpreting said command (C) so as to identify a decryption indication information (C 2 ) included therein indicating which parts of the received user data are encrypted and are to be decrypted before recording on said record carrier ( 10 ), decrypting the parts of said user data for which the associated decryption indication information (C 2 ) indicates that they are encrypted and are to be decrypted before recording on said record carrier ( 10 ), and recording said user data in sectors (S) on said record carrier ( 10 ) and a management information (M) associated with said sectors (S) comprising an encryption indication information (M 1 ) comprising a single bit associated with each of said sectors (S), (M 1 ) indicating that at least a part of the user data stored in sectors (S) associated with said management information (M) are to be encrypted by a read-out ( 2 ) device before transmission over a communication bus ( 6 ). 
     
     
       12. Recording method as claimed in  claim 11 , wherein said command (C) further comprises an encryption indication information (C 1 ) and that a decryption key for decryption of the user data is dependent on said encryption indication information (C 1 ). 
     
     
       13. A computer program embodied on a non-transitory computer-readable medium for reading data from a record carrier ( 10 ) storing user data in sectors (S) and management information (M) associated with said sectors (S), wherein said management information (M) comprises an encryption indication information (M 1 ) comprising a single bit associated with each of said sectors (S), each bit (M 1 ) indicating that at least a part of the user data stored in the associated sector are to be encrypted by a read-out ( 2 ) device before being transmitted over a communication bus ( 6 ), comprising:
 a code segment for reading said user data and said management information (M) from said record carrier ( 10 ), and 
 a code segment for interpreting said management information (M), encrypting user data of sectors (S) for which the associated encryption indication information (M 1 ) indicates that at least a portion of said user data are to be encrypted and outputting said user data, and 
 a code segment for interpreting said management information (M3) indicating which portions of said totality of user data stored in the associated sector (S) are to be encrypted while other parts of the associated sector (S) remain unencrypted. 
 
     
     
       14. A Personal Computer for use with a record carrier comprising user data arranged in sectors (S), and management information (M) associated with said sectors (S), said management information (M) comprising an encryption indication information (M1) comprising a single bit associated with each of said sectors (S), each bit indicating that at least a part of the user data stored in the associated sectors (S) are to be encrypted by a drive (2) before being transmitted over a communication bus (6), the Personal Computer comprising:
 a drive for reading user data stored on a record carrier;   a host system, comprising a CPU and memory;   a communication bus connecting the drive to the CPU and memory,   wherein the drive comprises a data interpreter (23) for interpreting said management information (M), and encryption unit (24) for encrypting user data of sectors (S) for which the associated encryption indication information (M1) indicates that at least a part of a totality of said user data are to be encrypted and an output unit (25) for outputting said user data onto the communication bus, and   wherein the host system is adapted for receiving said user data from the communication bus and decrypting the user data of the sectors which have been encrypted based on the associated encryption indication information (M1), and   wherein said management information (M) further comprises an encryption amount information (M3) indicating which part or parts of the user data of the sectors are to be encrypted while other parts of the sector remain unencrypted.   
     
     
       15. A Personal Computer for use with a drive comprising a data interpreter (23) for interpreting management information (M) comprising encryption indication information (M1) comprising a single bit associated with each of said sectors (S), each bit indicating that at least a part of user data of sectors (S) are to be encrypted, an encryption unit (24) for encrypting user data of sectors (S) for which the associated encryption indication information (M1) indicates that at least a part of said user data are to be encrypted, and an output unit (25) for outputting said user data onto a communication bus, the Personal Computer comprising:
 a host system comprising a CPU and memory;   a communications bus connected to the host system;   wherein the host system is adapted for receiving said user data from the communication bus and decrypting the user data of the sectors which have been encrypted based on the associated encryption indication information (M1) when the drive is connected to the communication bus.