Patent Publication Number: US-6343283-B1

Title: Data copyright management system

Description:
This application is a Continuation of prior application Ser. No. 09/206,455 filed Dec. 7, 1998 U.S. Pat. No. 6,081,789, which is a Continuation of prior application Ser. No. 08/663,463 filed Jun. 3, 1996, U.S. Pat. No. 5,848,158. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a system for managing copyrights for displaying, storing, copying, editing, or transferring digital data. 
     2. Background Art 
     In the information-oriented society of today, besides normal terrestrial broadcasting, satellite broadcasting, which is referred to as broadcasting satellites (BS) and communication satellites (CS), and cable TV broadcasting, which is referred to as CATV (cable television), using coaxial cables or optical cables are gaining wide spread acceptance. 
     In a satellite broadcasting or CATV broadcasting which distributes several tens of channels at the same time, scrambled channels of movies, sport events, and music which cannot be viewed through a comprehensive contract are provided in addition to unscrambled general channels. In order to view these scrambled channels, it is necessary to subscribe to descramble the channels; however, a normal subscription period is about one month, and it is often impossible to view through temporary contracts of shorter duration. 
     In the Japanese Patent Application Laid-Open No. 6-46419 and the Japanese Patent Application Laid-Open No. 6-141004, M. Saito proposed a system in which users obtain a viewing permit key from a charging center via a communication line and are charged, and descramble programs scrambled each by a different scramble pattern, using the viewing permit key to view the programs. An apparatus for such a system was also proposed in the Japanese Patent Application Laid-Open No. 6-132916. 
     In these system and apparatus, those who desire to use scrambled programs send a request for viewing to the charging center via a communication line by using a communication apparatus. The charging center transmits the viewing permit key to the communication apparatus corresponding to the request for viewing, and charges and collects the fee. 
     Users, on receiving the viewing permit key with the communication apparatus, transmit the viewing permit key to a receiving apparatus via direct means connecting the communication apparatus and the receiving apparatus or via indirect means such as flexible disks or the like. The receiving apparatus to which the viewing permit key is transmitted descrambles the programs using the viewing permit key. 
     Japanese Patent Application Laid-Open No. 6-132916 describes a system and an apparatus for selling and renting a tape or a disk on which a plurality of data scrambled with different scramble patterns respectively are recorded. Specific data can be utilized using the viewing permit key provided by IC cards or the like. 
     In addition, in today&#39;s information-oriented society, computer communication networks are available for mutually using data which are stored independently by each computer. Such computer communication networks include LAN (local area network), WAN (wide area network), or an international network known as Internet. 
     Recently, a new digitization technique has been developed for reducing the information amount by compressing a television moving picture signal which could not be digitized in the past because of a huge amount of information generated by digitization. So far, H.261 standards for video conference, JPEG (joint photographic image coding experts group) standards for static pictures, MPEG 1 (moving picture image coding experts group 1) standards for storing pictures and MPEG 2 standards to cover the current television broadcast and high-definition television broadcast are available. 
     The digitization technique using the picture compression technology can be used not only for the television broadcasting or the video picture recording, but also for television moving picture data which could not be handled by computer before. Thus, the “multimedia system” which can handle various types of data used by computers and digitized television moving picture data at the same time has attracted interest as a future technology. This multimedia system is also incorporated in the data communication and can be used as data on the database. 
     With the utilization range of databases being expanded, the method for charging for the data use on the database, and how to manage copyright problems associated with copying, transmitting other than direct use of data, and also the secondary exploitation right associated with data editing have become important issues. To prevent unauthorized use of data, it is necessary to take measures so that the data cannot be used by users other than authorized users, and data encryption is the best means for this purpose. 
     For the television systems, database systems or electronic commercial transaction systems or the like, a crypt key is required for encryption and decryption of data. A crypt key must be delivered to data users. However, the whole procedure for encryption and decryption is complicated because of tight security and high reliability requirements. 
     A general description of cryptography is provided below. 
     In the cryptography, the encryption to encrypt a plaintext M using a crypt key K and to obtain a cryptogram C is expressed as: 
     
       
           C=E ( K,M ) 
       
     
     and decryption to obtain a plaintext M from the cryptogram C using a crypt key K is expressed as: 
     
       
           M=D ( K,C ). 
       
     
     Further, M. Saito has proposed a concrete arrangement of a data copyright management system in Japanese Patent Application No. JP-A- 6-64889. In this system, in order to manage copyrights in display (including the process to turn to audio signal), storage, copying, editing and transferring of digital data in a database system including real-time transmission of digital picture, one or more of the programs to manage the copyrights, copyright information or the copyright management message are transmitted, when needed, in addition to a permit key to allow the user to utilize the encrypted data. 
     When the user attempts to utilize the data beyond the conditions of the permission or request, a copyright management message is displayed on the screen, to caution or warn the user. The copyright management program watches and manages in such manner that no utilization of data is performed beyond the conditions of request or permission. 
     The data is encrypted and supplied, and is then decrypted using a permit key to be utilized. When the data is stored in a device, is copied to a medium other than the device, or is transferred outside the device, re-encryption is performed. Also, a permit key is provided for each utilization such as displaying, using, storing, copying, editing, transferring, etc. 
     SUMMARY OF THE INVENTION 
     The system according to the present invention comprises a database, a key control center, a primary user, a secondary user, and a network system. The network system provides interconnections for the system elements. A primary copyright label, a primary use permit key including a first crypt key, a secondary use permit key including a second crypt key, a secondary copyright label, a third crypt key, and a copyright management program are used. 
     When a plaintext copyrighted primary data is supplied to a primary user, the data is encrypted using a first crypt key. When the primary user desires to utilize the encrypted copyrighted primary data, the user sends a request for distribution of a permit key for primary utilization via a network system to a key control center. When the request for distribution of the permit key for primary utilization is received from the primary user, the key control center sends the permit key for primary utilization to the primary user and charges the fee. 
     Using a first crypt key including in the received primary use permit key, the primary user decrypts the encrypted copyrighted primary data. In case the plaintext copyrighted primary data is stored in a device of the primary user, the data is re-encrypted using the primary use permit key. 
     When the primary user desires to utilize the copyrighted primary data, the primary user sends a request for distribution of a secondary use permit key for editing the plaintext copyrighted primary data to the key control center via the network system. The key control center sends the secondary use permit key to the primary user. 
     Upon receiving the secondary use permit key, the primary user copies the copyrighted primary data and edits the copy of the copyrighted primary data. When the plaintext copyrighted secondary data which is the copyrighted primary data being edited is stored in the device of the primary user, the data is encrypted using a second crypt key included in the secondary use permit key. When the final edited data is stored in the device of the primary user, the data is encrypted using a third crypt key. 
     As a result of secondarily processed data which is secondary data edition of the copyrighted data, the primary user now possesses the secondary exploitation right as secondarily generated copyright. In order to execute the secondary exploitation right, the third crypt key is registered at the key control center. The encrypted copyrighted secondary data obtained by encryption of the plaintext copyrighted secondary data using the third crypt key is sent to the secondary user by copying it to an external storage medium or by transferring it via the network system. 
     The secondary user who desires to utilize the encrypted copyrighted secondary data sends a request for distribution of the third crypt key to the key control center. Upon receiving the request for distribution of the third crypt key, the key control center sends the third crypt key to the secondary user via the network system. When the secondary user receives the third crypt key, the secondary user decrypts the encrypted copyrighted secondary data by third crypt key, and utilizes it. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of an embodiment of a data copyright management system according to the present invention. 
     FIG. 2 is a schematic block diagram of an embodiment of a system managing data copyrights according to the present invention. 
     FIG. 3 is a conceptual diagram for explaining limitation of primary utilization executed by a copyright management program Pc in the present invention. 
     FIG. 4 represents a conceptual drawing for explaining limitation of utilization of data editing executed by a copyright management program Pc in the present invention. 
     FIG. 5 is a block diagram for explaining a process for producing new copyrighted data from a plurality of a copyrighted data as objects. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is a database copyright management system. In the following description, numerous specific details are set forth to provide a more thorough description of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well known features have not been described in detail so as not to obscure the present invention. 
     The detailed embodiments of the invention are described below with reference to the drawings. 
     A system shown in FIG. 1 comprises a database  1 , a key control center  2 , users  3 , 3 , 3 , . . . and a network system  4 , which provide interconnections for system elements. To the database  1 , data is supplied from information providers (IP)  5 ,  5 ,  5 , . . . In some cases, the data is supplied to the user directly from the information providers  6 ,  6 ,  6 , . . . via the network system  4  without going through the database  1 . The data utilized in the present embodiment are objects where program and data are combined together. The users  3  are not mere utilizers, but can be information providers  5  or  6 , who provide secondary exploitation works, i.e. newly produced copyrighted works, by combining or modifying a plurality of copyrighted data, which they received. 
     In the data copyright management system according to the present invention as described above, each of the copyrighted data provided from the information providers  5  and  6  is encrypted to protect the copyright. Therefore, when the user  3  receives the encrypted copyrighted data, it must be decrypted to be utilized. For this purpose, all crypt keys are deposited to the key control center  2  in this system and are under the control of the key control center  2 . The cryptosystem adopted by each of the information providers  5  and  6  may be freely chosen, while the cryptosystem to be used in the secondary exploitation for secondarily utilizing data as described later is limited to the system adopted by the key control center. 
     The data from the database is generally utilized using personal computers, and the OS used in these personal computers must have security processing incorporated in it. For the control of crypt keys, the copyright management program is used. For the storage of the copyright management program and the crypt keys received from the key control center  2 , “key cards” realized as software on memory or HDD (Hard Disk Drive) or realized as hardware in form of a unique board, PC card, etc. are prepared as the storage area. 
     The key control center stores the crypt keys for protection of copyright of data and for charging fees for utilization of the copyright regardless of whether the data is actually utilized or simply registered and not utilized, and controls the crypt keys by coordinating the stored keys with copyright labels. 
     FIG. 2 represents a schematic configuration of an embodiment of a data copyright processing system according to the present invention, in which a primary user receiving data from an information provider edits the received data and supplies the edited data to a secondary user. In this system, a plaintext copyrighted primary data D 1 , an encrypted copyrighted primary data ED 1 i, a plaintext copyrighted secondary data D 2 , an encrypted copyrighted secondary data ED 2 j, a plaintext primary copyright label Lc 1 , a primary use permit key K 1  including a first crypt key K 1 i, a secondary utilization permit key K 2 , a third crypt key K 3 j, and a plaintext copyright management program Pc are used. 
     The system shown in FIG. 2 comprises a database  11 , a key control center  12 , a primary user  13 , a secondary user  19 , and a network system  14  for connecting the system elements. To the database  11 , data are supplied from information providers  15 , 15 ,  15 , . . . In some cases, the data may be supplied to the user  13  from the information providers  16 ,  16 ,  16 , . . . via the network system  14  or directly via an information recording medium  17  such as a CD-ROM from the information providers  16  without going through the database  11 . In FIG. 2, solid lines represent paths of plaintext data, broken lines represent paths of encrypted data, and dotted lines represent paths of keys. 
     In this system, the plaintext copyrighted primary data D 1 i is supplied to the primary user  13  under the copyrighted primary data ED 1 i encrypted using the first crypt key K 1 i: 
     
       
           ED   1   i=E ( K   1   i, D   1   i ) 
       
     
     from the information provider  15  via the network system  14  through the database  11 , or from the information provider  16  via the network system  14 , or via an information recording medium  17  such as a CD-ROM. The primary user  13  who desires to utilize the encrypted copyrighted primary data ED 1 i and is thus supplied sends a request for distribution of a primary use permit key K 1  by presenting a primary copyright label Lc 1  to the key control center  12  via the network system  14 . 
     Upon receiving the request for distribution of the primary use permit key K 1  from the primary user  13 , the key control center  12  searches for the primary use permit key K 1  using the presented primary copyright label Lc 1  and sends the primary use permit key K 1  to the primary user  13  via the network system  14  and charges the fee at the same time. The primary user  13  decrypts the encrypted copyrighted primary data Ed 1 i using the first crypt key K 1 i included in the received primary use permit key K 1 : 
     
       
           D   1   i=D ( K   1   i, ED   1   i ) 
       
     
     and utilizes it. 
     In case the decrypted plaintext copyrighted primary data D 1 i is stored in a device of the primary user  13 , it is re-encrypted using the first crypt key K 1 i: 
     
       
           Ed   1   i=E ( K   1   i, D   1   i ), 
       
     
     and the re-encrypted copyrighted primary data Ed 1 i is stored. In case the re-encrypted copyrighted primary data Ed 1 i is to be utilized again, the encrypted copyrighted primary data Ed 1 i is re-decrypted and re-encrypted. 
     The primary user  13 , who desires to edits the plaintext copyrighted primary data D 1 i, sends a request for distribution of the secondary use permit key K 2  for editing of the plaintext copyrighted primary data D 1 i to the key control center  12  via the network system  14 . 
     Upon receiving the request for distribution of the secondary use permit key K 2 , the key control center  12  sends the secondary use permit key K 2  to the primary user  13  via the network system  14 . When the secondary use permit key K 2  is received, the primary user  13  edits the plaintext copyrighted primary data D 1 i according to the content of the permit key and obtains the plaintext copyrighted secondary data D 2 j. In case the plaintext copyrighted secondary data D 2 j is to be stored in a device of the primary user  13 , the plaintext copyrighted secondary data D 2 j is encrypted using the second crypt key K 2 : 
     
       
           ED   2   j=E ( K   2 ,  D   2   j ). 
       
     
     When the editing is complete, the primary user  13  generates a third crypt key K 3 j in order to execute the secondary exploitation right for data editing of the copyrighted secondary data, and the third crypt key K 3 j thus generated is registered at the key control center  12 . The third crypt key may not be generated by the primary user  13 , but it may be prepared and distributed by the key control center at the request of the primary user  13 . 
     In case the primary user  13  copies the plaintext copyrighted secondary data D 2 j to an external storage medium  18  or transfers it via the network system  14 , the plaintext copyrighted secondary data D 2 j is encrypted using the third crypt key: 
     
       
           ED   2   j=E ( K   3   j, D   2   j ), 
       
     
     and the encrypted copyrighted secondary data ED 2 j is supplied to a secondary user  19 . 
     The secondary user  19 , who desires to utilize the encrypted copyrighted secondary data ED 2 j and is thus supplied, sends a request for distribution of the third crypt key K 3 j to the key control center  12  via the network system  14 . Upon receiving the request for distribution of the third crypt key K 3 j from the secondary user  19 , the key control center  12  sends the third crypt key K 3 j to the secondary user  19  via the network system  14 . When the third crypt key K 3 j is received, the secondary user  19  decrypts the encrypted copyrighted secondary data ED 2 j using the third crypt key K 3 j: 
     
       
           D   2   j=D ( K   3   j, ED   2   j ) 
       
     
     and utilizes it. In the case that the encrypted copyrighted secondary data ED 2 j is to be utilized again, the encrypted copyrighted secondary data ED 2 j is decrypted and encrypted using the third crypt key K 3 j. 
     In the following, detailed description will be given on acquisition of the copyrighted primary data, primary utilization of the copyrighted primary data, editing of the copyrighted primary data to the copyrighted secondary data, supply of the edited copyrighted secondary data, and utilization of the copyrighted secondary data. In this system, a plurality of plaintext copyrighted primary data D 1 i are supplied to the primary user  13  with the encrypted copyrighted primary data Ed 1 i using the first crypt key K 1 i 
     
       
           ED   1   i=E ( K   1   i, D   1   i ) 
       
     
     together with the plaintext primary copyright label Lc 1  directly from the information provider  16  or via the database  11 . 
     The copyright management program Pc manages the use of the copyrighted data by the user. More specifically, the copyrighted data is decrypted and re-encrypted using crypt key and utilization of the copyrighted data is restricted according to the content of the use permit key. In this system, a plaintext primary copyright label Lc 1  to be utilized for acquisition of crypt key is attached to the encrypted data ED 1 j. In other words, the encrypted copyrighted primary data ED 1 j comprises a plaintext copyright label Lc 1  and the encrypted copyrighted primary data ED 1 i. On the plaintext primary copyrighted label Lc 1 , title of the data and name of the application program used and the name of the primary copyright owner, etc. are entered. 
     The primary user  13  who desires to utilize the encrypted copyrighted primary data Ed 1 i and is thus supplied sends a request for distribution of the primary use permit key K 1  by presenting the plaintext primary copyright label Lc 1  to the key control center  12  via the network system  14 . 
     After confirming that the primary use permit key to be distributed is the key K 1  using the presented primary copyright label Lc 1 , the key control center  12  sends the primary use permit key K 1  thus confirmed to the primary user  13  via the network system  14 . When the primary use permit key K 1  is received, the device of the primary user  13  is turned to copyright management mode, and the primary user  13  is now entitled to utilize the copyrighted primary data. Because the first crypt key K 1 i is included in the primary use permit key K 1 , the first crypt key K 1 i is not recognized by the primary user  13 . On the other hand, the key control center  12  charges and collects the fee and identifies the status of use of the copyrighted data and the status of utilization of database of the primary user  13 . 
     FIG. 3 is a conceptual diagram for explaining restriction of the primary utilization by the copyright management program Pc in the present invention. Similarly to the system described in Japanese Patent Application No. 6-64889, the primary utilization of the data obtained in the data copyright management system of the present invention is limited to ordinary utilization, i.e., direct utilization of the data and output including printing of utilization results, and it is not allowed to copy the data to an external storage medium or to edit and transfer via a network system or in principle, to store the data inside the device. However, it is possible to store the data when encrypted. It is needless to say that the data D other than the copyrighted data can be displayed, printed, stored, copied, edited or transferred by the application program in use. 
     In FIG. 3, reference numeral  21  represents a storage unit such as a non-volatile semiconductor memory or a hard disk drive incorporated in a device  20  of the primary user, reference numeral  22  represents a display unit for output,  23  represents a printing unit for output, D 1  represents a copyrighted primary data, D represents a non-copyrighted general data,  24  represents a secondary user, to whom the data is supplied by copying via a flexible disk or a CD-ROM or by transferring using a network system. In FIG. 3, solid lines represent processing routes permitted, and broken lines show processing routes not permitted. 
     The encrypted copyrighted primary data ED 1 i acquired by the primary user  13  from external information providers  15  or  16  either directly or via the data base  11  is incorporated with a plaintext primary copyright label Lc 1  which is supplied together with the data ED 1 i, and is stored in a storage unit  21  of the primary user device  20 . 
     The primary user  13  who desires to utilize the encrypted copyrighted primary data ED 1 i stored in the storage unit  21  refers to general description of the encrypted copyrighted primary data ED 1 i and a plaintext primary copyright label Lc 1  that shows information of application program used by the encrypted copyrighted primary data ED 1 i using the copyright management program Pc, and identifies the use environment of the encrypted copyrighted primary data ED 1 i such as presence or absence of an application program used for preparation of the encrypted copyrighted primary data ED 1 i. 
     As a result, it is judged that the encrypted copyrighted primary data ED 1 i can be utilized. When the primary user  13  inputs request for the use of the encrypted copyrighted primary data ED 1 i to the copyright management program Pc, the copyright management program Pc starts the application program used by the encrypted copyrighted primary data ED 1 i and reads the encrypted copyrighted primary data ED 1 i from the storage unit  21  to memory in the primary user device  20 . On the other hand, the plaintext copyright label Lc 1  is sent to the key control center  12 , and the primary use permit key K 1  is supplied to the primary user in accordance with the processing flow already described. The encrypted copyrighted primary data ED 1 i is decrypted to the plaintext copyrighted primary data D 1 i, using the first crypt key K 1 i included in the primary use permit key K 1   
     
       
           D   1   i=D ( K   1   i, ED   1   i ), 
       
     
     and it can be used by the started application program. 
     If the plaintext copyrighted primary data D 1 i on memory of the primary user device  20  is to be stored in the storage unit  21 , the plaintext copyrighted primary data D 1 i is re-encrypted using the first crypt key K 1 i 
     
       
           ED   1   i=E ( K   1   i, D   1   i ), 
       
     
     and it is stored. The storage includes producing and storing temporary file for data maintenance. In case the re-encrypted data ED 1 i is to be re-used, re-decryption and re-encryption are performed using the first crypt key K 1 i. The utilization other than displaying and printing, storage or editing, i.e. copying to an external storage medium or transfer to other device, of the plaintext copyrighted primary data D 1  or the encrypted copyrighted primary data ED 1 i are prohibited by the copyright management program Pc. 
     As described above, in the data copyright management system of the present invention, the utilization of the obtained copyrighted data is limited to ordinary modes of utilization, i.e. direct utilization by displaying the data on the display unit  22  or output of the utilization results by the printer  23 . Copying of the data to an external storage medium or transfer of the data to the secondary user  24  via the network system and editing the data are prohibited by the copyright management program. Therefore, it is not allowed to cut and paste a part of the copyrighted primary data D 1 i to the other data D or to cut and paste a part of the other data D to the copyrighted primary data D 1 i. The copyrighted primary data D 1 i can be stored to the storage unit  21  exceptionally if it is in the encrypted state using the first crypt key K 1 i, but it cannot be stored if it has been edited. 
     In the data copyright management system of the present invention, distinguishing the copyrighted primary data D 1  from general data D and determining as to whether the copyrighted data has been edited or not are performed by the copyright management program Pc. Computer file comprises a data file main unit and a management table that includes attributes of the data file. Therefore, by investigating the management table, it can be judged whether the file is the copyrighted data or not. On this management table, data file size and date and time of produced are entered. By investigating these in the management table, it can be judged whether the file has been edited or not. 
     When stored in the storage unit  21 , the copyrighted primary data D 1 i is to be encrypted and coupled with the primary copyright label Lc 1 . When the data is decrypted and is read on memory, the copyrighted primary data D 1 i and the primary copyright label Lc 1  are separated from each other by the copyright management program, and the separated copyright label Lc 1  is managed by the copyright management program Pc. The copyright management program watches by which application program the copyrighted primary data D 1 i is used and prohibits “cut and paste” of the copyrighted primary data D 1 i to the non-copyrighted general data D and “cut and paste” of the non-copyrighted general data D to the copyrighted primary data D 1 i. 
     FIG. 4 is a conceptual drawing for explaining restriction of utilization in the data editing executed by the copyright management program Pc in the present invention. The primary user  13  who desires to edit the plaintext copyrighted primary data D 1 i, in the primary utilization, notifies the key control center via the network  14  that the plaintext copyrighted primary data D 1 i is to be edited and sends a request for distribution of the secondary use permit key K 2  necessary for the edit of the plaintext copyrighted primary data D 1 i to the key control center  12  via the network system  14 . 
     Upon receiving the request for distribution of the secondary use permit key K 2  from the primary user  13 , the key control center  12  sends the secondary use permit key K 2 j to the primary user  13  via the network system  14 . As a result, the primary user device  20  of the primary user  13  is turned to edit mode, and the primary user  13  can edit the encrypted copyrighted primary data ED 1 i. 
     The primary user  13  decrypts the encrypted copyrighted primary data ED 1 i to the plaintext copyrighted primary data D 1 i using the first crypt key K 1 , displays it on the display unit  22 , and edits the data. To protect the copyright of the copyrighted primary data at first, the plaintext copyrighted primary data D 1 i for editing is copied, and the plaintext copyrighted primary data D 1 i′ for edit obtained by this copying is edited. 
     The primary user  13  decrypts the encrypted copyrighted primary data ED 1 i to the plaintext copyrighted primary data D 1 i to display on the display unit  22 , and before editing, copies the plaintext copyrighted primary data D 1 i for edit and edits the plaintext copyrighted primary data for editing, D 1 i′, obtained by copying. If the plaintext copyrighted primary data for editing D 1 i′ or the plaintext copyrighted primary data D 1 i″ being edited is to be stored in the primary user device of the user  13 , encryption is performed using the secondary use permit key K 2   
     
       
           ED   1   i′=E ( K   2 ,  D   1   i ′) 
       
     
     or 
     
       
           ED   1   i″=E ( K   2 ,  D   1   i ″), 
       
     
     and it is stored as the encrypted copyrighted primary data ED 1 i′ or as the encrypted copyrighted primary data ED 1 i″. As the encrypted copyrighted primary data ED 1 i is stored in the storage unit  21  without being edited, by comparing its management table with file size, creation date and time of the plaintext copyrighted primary data for editing D 1 i′ or D 1 i″ which has been edited, it is judged whether the file is the edited file or not. 
     When editing of the data has been completed, a plurality of new plaintext copyrighted secondary data D 2 j is produced, and secondary exploitation right as secondary copyrights is newly generated on the data D 2 j. To protect the secondary exploitation right, the primary user  13  who edited the plaintext primary copyrighted data D 1 i sends a request for distribution of the third crypt key K 3 j to the key control center  12 . Upon receiving the request for distribution of the third crypt key K 3 j, the key control center  12  sends the third crypt key K 3 j to the primary user  13  via the network system  14 . 
     When the third crypt key K 3 j is received, the primary user  13  encrypts the plaintext copyrighted secondary data D 2 j using the third crypt key K 3 j: 
     
       
           ED   2   j=E ( K   3   j, D   2   j ), 
       
     
     and the encrypted copyrighted secondary data ED 2 j is stored in the storage unit  21  of the primary user  13 . If the encrypted copyrighted data ED 2 j is to be utilized, decryption and encryption are performed using the third crypt key K 3 j. 
     In the plaintext copyrighted secondary data D 2 j edited by the primary user  13 , secondary exploitation right in data editing of the primary user  13  is present in addition to the primary copyright of the plaintext copyrighted primary data D 1 i which is before editing and owned by the information provider. To execute the secondary exploitation right, the primary user  13  sends information such as title of the data, name of the application program used, outline of the content, name of the primary copyright owner, etc. together with the third crypt key K 3 j to the key control center  12 . The key control center stores and controls these together with the third crypt key K 3 j. 
     On the other hand, the primary user  13  supplies the encrypted copyrighted secondary data ED 2 j to the secondary user  24  by copying it to an external storage medium  18  or by transferring it via the network system  14 . 
     The secondary user  24  who desires to utilize the supplied encrypted copyrighted secondary data ED 2 j sends a request for distribution of a use permit key including the third crypt key K 3 j to the key control center  12 . The utilization of the plaintext copyrighted secondary data D 2 j using the use permit key including the third crypt key K 3 j is limited to general utilization of the plaintext copyrighted secondary data D 2 j or to storage to the user device, and it is not allowed to copy the plaintext copyrighted secondary data D 2 j or the encrypted copyrighted secondary data ED 2 j to an external storage medium  18 , to transfer it to a third user via the network  14 , or to edit the plaintext copyrighted secondary data D 2 j. 
     As described above, the copyrighted data handled in the present invention is directed to “object” where program and data are integrated, and the object can be processed as parts-like through computer programming or various types of processing. 
     Description will be given below on the case where new copyrighted data is produced utilizing a plurality of copyrighted data that are objects, referring to FIG.  5  and FIG.  2 . 
     In FIG. 5, reference numerals  31 ,  32  and  33  represent copyrighted primary data D 11 , D 12  and D 13  which comprise objects respectively. By utilizing the copyrighted primary data D 11 , D 12  and D 13 , the new copyrighted secondary data D 2 j represented by  30  is produced. The utilization of the copyrighted data D 11 , D 12  and D 13  include three editorial forms: utilization of whole parts such as the copyrighted data D 11  shown by reference numeral  34 ; utilization of a part such as the copyrighted data D 12 ′ as shown by reference numeral  35 ; and utilization after modifying such as the copyrighted data D 13 ′ as shown by reference numeral  36 . 
     The copyrighted data are edited by linking in object-unit, referring, embedding and combining them. Such embedding and combining can be performed freely. Also, it is possible to add other matters to the copyrighted data  37 , which has been thus embedded and combined. The newly produced copyrighted data D 2 j in this way consists of an assembly of objects. 
     In the plaintext copyrighted secondary data D 2 j thus produced, secondary exploitation right of the primary user  13  who has newly produced arises in addition to the copyright of the copyrighted primary data D 1 i. To execute the secondary exploitation right, it is necessary to encrypt the plaintext copyrighted secondary data. For this purpose, the primary user  13  prepares the third crypt key K 3 j and encrypts the plaintext copyrighted data D 2 j using the third crypt key K 3 j: 
     
       
           ED   2   j=E ( K   3   j, D   2   j ), 
       
     
     and the encrypted copyrighted data ED 2 j is supplied to the secondary user  19  by copying it to an external storage medium  18  or by transferring it via the network  14 . In order that a tertiary user can easily receive the third crypt key K 3 j, the third crypt key K 3 j is registered at the key control center  12 . By registering the third crypt key K 3 j, the secondary exploitation right of the primary user  13  is recorded at the key control center  12 . 
     In this case, the information sent from the primary user  13  to the key control center  12  at this time includes, in addition to a plurality of the third crypt keys K 3 j the number of which corresponds to the produced plural copyrighted secondary data, the number of the third crypt keys K 3 j, the second crypt key K 2 j, the copyrighted primary data used, information of the other copyrighted data to which the copyright management program is linking, access path to the copyrighted data used, application program used by the copyrighted data used, and explanation of the copyright works. 
     The secondary user  19 , who desires to utilize the encrypted copyrighted secondary data ED 2 j and is thus supplied, sends a request for distribution of the third crypt key K 3 j to the key control center  12 . Upon receiving the request for distribution of the third crypt key K 3 j, the key control center  12  sends the third crypt key K 3 j to the secondary user  19  via the network system  14 . The secondary user  19  receives the third crypt key K 3 j, decrypts the encrypted copyrighted secondary data ED 2 j using the third crypt key K 3 j, and utilizes it. 
     When the third crypt key K 3 j is received, the copyright management program Pc attaches the copyright label Lc 2 j to each copyrighted data D 2 j so that the secondary user can utilize it. At this time, the linkage with the copyrighted data, which is the object linked with the newly produced copyrighted data, is released. At the time of the release of the linkage, the entity of the copyrighted primary data, which has had so far relationship as the linkage only, is embedded into the encrypted copyrighted secondary data ED 2 j, thereby allowing distribution as a copyright work only through ED 2 j file. In this case, if the encrypted copyrighted secondary data ED 2 j is to be utilized again, decryption and encryption are performed using the third crypt key K 3 j. 
     The key control center sends back the third crypt key K 3 j to the requester, and charges and collects the fee according to the copyright labels Lc 1  and Lc 2 . The copyright owner of the copyrighted data can change access path of own copyrighted data by applying to the key control center. The copyright owner of the copyrighted data can also edit (modify) his own copyrighted data using the third crypt key K 3 j and also can register it using another key. 
     Thus, a method and apparatus for database copyright control has been described in conjunction with one or more specific embodiments. The invention is defined by the claims and their full scope of equivalents.