Data management system

• US 6,002,772 A
• Filed: 04/02/1997
• Issued: 12/14/1999
• Est. Priority Date: 09/29/1995
• Status: Expired due to Term

• Current Assignee: Piracy Protection LLC (LF Capital Partners, LLC)
• Original Assignee: Mitsubishi Corporation
• Inventors: Saito, Makoto
• Primary Examiner(s): Hayes, Gail O.
• Assistant Examiner(s): SAYADIAN, HRAYR
• Application Number:
  US08/825,868
• Time in Patent Office: 986 Days
• Field of Search: 380/4, 380/49, 380/23, 380/25, 380/21
• US Class Current: 705/58
• CPC Class Codes: G06F 21/109 by using specially-adapted hardware at the client
• CPC Class Codes: G06F 2221/2107 File encryption
• CPC Class Codes: G06Q 20/00 Payment architectures, schemes or protocols apparatus for performing or posting payment transactions G07F7/08, G07F19/00; electronic cash registers G07G1/12
• CPC Class Codes: G06Q 20/02 involving a neutral party, e.g. certification authority, notary or trusted third party [TTP]
• CPC Class Codes: G06Q 20/06 Private payment circuits, e.g. involving electronic currency used among participants of a common payment scheme
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: H04L 2463/101 applying security measures for digital rights management
• CPC Class Codes: H04L 63/0442 wherein the sending and receiving network entities apply asymmetric encryption, i.e. different keys for encryption and decryption cryptographic mechanisms or cryptographic arrangements for public-key encryption H04L9/30
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04N 21/2541 Rights Management protecting software against unauthorised usage in a vending or licensing environment G06F21/10; security in data switching network management H04L41/28; security management or policies for network security H04L63/20; access security in wireless networks H04W12/08
• CPC Class Codes: H04N 21/42684 Client identification by a unique number or address, e.g. serial number, MAC address, socket ID network arrangements, protocols or services for addressing or naming H04L61/00
• CPC Class Codes: H04N 21/835 Generation of protective data, e.g. certificates protecting software against unauthorised usage in a vending or licensing environment G06F21/10
• CPC Class Codes: H04N 21/8352 involving content or source identification data, e.g. Unique Material Identifier [UMID]
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58

Abstract

To prevent piracy or leakage of data content, a cryptography technique and electronic watermark technique are combined together and used. In a data content supplied to a user, a user data is entered as electronic watermark by a data management center, and the data content with an electronic watermark entered in it is encrypted using a crypt key and is supplied. The encrypted data content is decrypted using a crypt key distributed from the data management center and is used. In case it is to be stored, it is encrypted using another crypt key. In case the data content is copied and transferred to other user, a user data of the other user is entered as electronic watermark, and a scenario to enter the user data of the other user as electronic watermark is registered at the data management center, and the data content with electronic watermark entered in it is encrypted using another crypt key and is supplied. When the validity of the other user is confirmed by the scenario, another crypt key is distributed to the other user. The encrypted data content is decrypted using another crypt key and is used. When it is to be stored, it is encrypted using still another key. In case the data content has been copied and transferred illegitimately, it is possible by verifying the electronic watermark to identify the user who has copied and transferred the data content illegitimately.

Claims

1. A method for managing the use of data content by a data management center comprising a data center and a key center, said method comprising the steps of:

said key center receiving a data content name, first user data, and a request for distribution of a first secret-key and a second secret-key from a first user;

said key center generating said first secret-key and said second secret-key, storing said data content name, first user data, first secret-key and second secret-key, and distributing said first secret-key and second secret-key to said first user;

said first user storing said first secret-key and said second secret-key in a storage unit;

said first user presenting said first user data to said data center, specifying said data content name, and requesting said data center to distribute said data content;

said data center transferring said first user data and said data content name to said key center and requesting transfer of said first secret-key and said second secret-key;

said key center transferring said first secret-key and said second secret key to said data center;

said data center entering said first user data as an electronic watermark in said data content requested by said first user, editing said data content to a first edited data content, encrypting said first edited data content using said first secret-key to obtain an encrypted first edited data content, distributing said encrypted first edited data content to said first user, and storing a first scenario of editing process of said first edited data content;

said first user decrypting said encrypted first edited data content using said first secret-key and using said first edited data content thus decrypted, and abandoning said first secret key;

said first user encrypting said first edited data content using said second secret-key and storing said encrypted first edited data content;

said first user re-decrypting said encrypted first edited data content using said second secret-key and re-using said first edited data content;

said first user re-encrypting said first edited data content using said second secret-key and storing said encrypted first edited data content;

said first user entering a second user data as an electronic watermark in said first edited data content to edit said first edited data content to a second edited data content, encrypting said second edited data content using said second secret-key to obtain an encrypted second edited data content, transferring said encrypted second edited data content to a second user, and transferring a second scenario of editing process of said second edited data content to said key center;

said key center registering said second scenario of editing process;

said second user specifying said data content name to said key center, presenting said second user data, and requesting distribution of said second secret-key and a third secret-key;

said key center confirming by said second scenario that said second user is a valid user, generating and storing said third secret-key, and distributing said second secret-key and said third secret-key to said second user;

said second user decrypting said encrypted second edited data content using said second secret-key, using said second edited data content thus decrypted, and abandoning said second secret-key;

said second user re-encrypting said second edited data content using said third secret-key and storing said encrypted second edited data content;

said second user decrypting said encrypted second edited data content using said third secret-key and re-using said second edited data content;

said second user re-encrypting said second edited data content using said third secret-key and storing said encrypted second edited data content.

2. A method for managing the use of data content by a data management center comprising a data center and a key center, said method comprising the steps of:

said key center receiving a data content name, first user data, and a request for distribution of a first secret-key and a second secret-key from a first user;

said key center generating said first secret-key and said second secret-key, storing said data content name, first user data, first secret-key and second secret-key, and distributing said first secret-key and second secret-key to said first user;

said first user storing said first secret-key and said second secret-key in a storage unit;

said first user presenting said first user data to said data center, specifying said data content name, and requesting said data center to distribute said data content;

said data center transferring said first user data and said data content name to said key center and requesting transfer of said first secret-key and said second secret-key;

said key center transferring said first secret-key and said second secret key to said data center;

said data center entering said first user data as an electronic watermark in said data content requested by said first user, editing said data content to a first edited data content, encrypting said first edited data content using said first secret-key to obtain an encrypted first edited data content, distributing said encrypted first edited data content to said first user, and storing a first scenario of editing process of said first edited data content;

said first user decrypting said encrypted first edited data content using said first secret-key and using said first edited data content thus decrypted, and abandoning said first secret key;

said first user encrypting said first edited data content using said second secret-key and storing said encrypted first edited data content;

said first user re-decrypting said encrypted first edited data content using said second secret-key and re-using said first edited data content;

said first user re-encrypting said first edited data content using said second secret-key and storing said encrypted first edited data content;

said first user entering a second user data as an electronic watermark in said first edited data content to edit said first edited data content to a second edited data content, encrypting said second edited data content using said second secret-key to obtain an encrypted second edited data content, transferring said encrypted second edited data content to a second user, and transferring a second scenario of editing process of said second edited data content to said key center;

said key center registering said second scenario of editing process;

said key center generating a third secret-key, storing said second scenario of editing process and said third secret-key, and distributing said third secret-key to said first user;

said first user encrypting said second edited data content using said third secret-key and transferring said encrypted second edited data content to said second user;

said second user specifying said data content name to said key center, presenting said second user data, and requesting distribution of said third secret-key and a fourth secret-key;

said key center confirming by said second scenario that said second user is a valid user, generating and storing said fourth secret-key, and distributing said third secret-key and said fourth secret-key to said second user;

said second user decrypting said encrypted second edited data content using said third secret-key, using said second edited data content thus decrypted, and abandoning said third secret-key;

said second user re-encrypting said second edited data content using said fourth secret-key and storing said encrypted second edited data content;

said second user decrypting said encrypted second edited data content using said fourth secret-key and re-using said second edited data content;

said second user re-encrypting said second edited data content using said fourth secret-key and storing said encrypted second edited data content.

3. A method for managing the use of data content by a data management center comprising a data center and a key center, said method comprising the steps of:

said data management center receiving a data content name, first user data, and a request for distribution of a first secret-key, a second secret-key, and a first data content from a first user;

said data management center generating said first secret-key and said second secret-key, storing said data content name, said first user data, said first secret-key and said second secret-key, entering said first user data as an electronic watermark in said first data content to edit said first data content to a first edited data content, encrypting said first edited data content using said first secret-key to obtain an encrypted first edited data content, distributing said encrypted first edited data content to said first user, and storing a first scenario of editing process of said first edited data content;

said first user storing said first secret-key and said second secret-key in a storage unit, decrypting said encrypted first edited data using said first secret key, using said first edited data content thus encrypted, and abandoning said first secret-key;

said first user encrypting said first edited data content using said second secret-key and storing said encrypted first edited data content in said storage unit;

said first user decrypting said encrypted first edited data content again using said second secret-key and re-using said first edited data content;

said first user re-encrypting said first edited data content again using said second secret-key and storing said encrypted first edited data content in said storage unit;

said first user entering a second user data as an electronic watermark in said first edited data content to edit said first edited data content to a second edited data content, encrypting said second edited data content using said second secret-key to obtain an encrypted second edited data content, transferring said encrypted second edited data content to a second user, and transferring a second scenario of editing process of said second edited data content to said data management center;

said data management center registering said second scenario of editing process;

said second user specifying said data content name to said data management center, presenting said second user data to said data management center, and requesting distribution of said second secret-key and a third secret-key;

said data management center confirming by said second scenario of editing process that said second user is a valid user, generating and storing said third secret-key, and distributing said second secret-key and said third secret-key to said second user;

said second user decrypting said encrypted second edited data using said second secret-key, using said second edited data content thus decrypted, and abandoning said second secret-key;

said second user re-encrypting said second edited data content using said third secret-key and storing said encrypted second edited data content;

said second user decrypting said encrypted second edited data content using said third secret-key and re-using said second edited data content;

said second user re-encrypting said second edited data content and storing said encrypted second edited data content.