Copyright control system

Abstract: A copyright control system for performing access control to copyright digital information. The copyright control system is equipped with an encryption/decryption hardware 11 which accepts encrypted copyright digital information from an option hardware 6 or an FDD unit 3 through a sub-data bus 23. The encryption/decryption hardware 11 decrypts the encrypted digital information using a decryption key obtained from a copyright control center for primary utilization of the encrypted digital information and inputted from an CPU 1.

Description: BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to a system for controlling or managing the copyrights of digitized information on computers. DESCRIPTION OF THE RELATED ART An arrangement of a general computer is shown in a block diagram of Fig. 8, comprising a central processing unit (CPU) 1, a fixed disk unit (HDD) 2, a floppy disk unit (FDD) 3, a printer 4, an interface 5 for connections to external networks such as an RS-232C port, an option hardware 6 such as a CD-ROM drive, a video signal input unit, a broadcast wave receiver, a scanner and an extended HDD, a ROM 7, a main storage RAM 8, a video RAM 9 for storage of display data to a CRT, and a main data bus 22 for transmission and reception of information between these components. In operation, copyright (copyright-claimed) digital information, supplied with a recording medium such as a CD-ROM and an FDD, is delivered from- a CD-ROM drive serving as the option hardware 6 or from the FDD 3 through the main data bus.22 to the main storage RAM 8 and stored therein. Subsequently, in accordance with a program stored in the main storage RAM 8 or the ROM 7, this information is expanded and converted with the CPU 1 connected through the data bus 22 thereto or with a dedicated expansion and conversion unit coupled to the option hardware 6, before being displayed on a CRT unit (not shown) through the main data bus 22 and the video RAM 9. However, because the prior general computer has the above-mentioned arrangement, the digital information stored in the main storage RAM 8 is easily reproducible and transmittable through the HDD 2, the FDD 3 or the interface 5 for the connections to the external networks, which is in connection with the main data bus 22, and hence there is a problem in that, irrespective of having intention or no intention, the invasion of the copyright which is an legal right the producer has can easily occur with respect to the copyright digital information supplied with a recording medium such as a CD-ROM and an FDD. EP 0,715,241 A2, which has been filed before the priority date of the present application and published after the priority date, discloses a copyright control system, wherein encrypted data are received via a communication unit or a disk drive. The encrypted data are sent to a decrypting means via a system bus and a local bus. Further, this system provides for the reencryption of digital data in order to store/copy/transfer the reencrypted data so that no unauthorized use of the data can be available. US 5,319,705 discloses a system for securely distributing a plurality of software files from a software distribution processor to a user processor. EP 0,421,409 A3 further discloses a transaction system security method and apparatus using an IC-card to enhance security functions across a total system or method. SUMMARY OF THE INVENTION The present invention has been developed with a view to eliminating the above-mentioned problem, and it is therefore an object of the present invention to provide a copyright control system which can realize the access control to the copyright digital information carried on a recording medium such as a CD-ROM and an FDD and which has a copyright control function to make an encryption in reproducing and sending digital information through an HDD, an FDD or an interface for connections to external networks, which is coupled to a main data bus, and further to provide an encryption/decryption (encoding/decoding) hardware available for the copyright control system. This object is solved by a copyright control system according to claim 1 or claim 2. Further developments of this system are provided in the dependent claims. In the present invention, there is provided a copyright control system comprising decryption means which accepts encrypted (enciphered) copyright digital information to decrypt (decipher) the encrypted digital information by means of a decryption key obtained from a copyright control center for primary utilization of the encrypted digital information and/or encryption means which accepts copyright digital information to encrypt the digital information by means of an encryption key obtained from a copyright control center for secondary utilization of the digital information. The copyright control system further comprises a central information unit and/or central information processing unit and a main data bus connected to the central information unit, the decryption means and/or encryption means being coupled to the main data bus. The copyright control system further comprises an information processing means to perform at least one of communication, broadcast, storage and copy of the digital information encrypted by the encryption means. The copyright control system may comprises an auxiliary memory and/or a network connection unit and a sub-data bus coupled to the auxiliary memory and/or the network connection unit, the decryption means and/or encryption means being coupled to the sub-data bus. The copyright control system may further comprise further information processing means to implement at least one of display, process and edit of the digital information decrypted by the decryption means. Further, the decryption means or encryption means may be provided in an LSI, an extended board or a PC card. BRIEF DESCRIPTION OF THE DRAWINGS The object and features of the present invention. will become more readily apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings in which: Fig. 1 is a block diagram showing a copyright control system according to a first embodiment of the present invention; Fig. 2 is a block diagram showing a copyright control system; Fig. 3 is a block diagram showing a copyright control system; Figs. 4A and 4B are flow charts available for describing an operation of a cipher processing program; Fig. 5 is a block diagram showing an encryption/decryption hardware; Fig. 6 is a block diagram showing an encryption/decryption hardware; Fig. 7 is a block diagram showing an encryption/decryption hardware; and Fig. 8 is a block diagram showing a prior general computer. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Embodiment A description will be made hereinbelow of a first embodiment of the present invention with reference to Fig.1. In Fig. 1, a copyright control system is shown as comprising an encryption/decryption hardware 11 and a sub-data bus 23 coupled to the encryption/decryption hardware 11. The encryption/decryption hardware 11 is also connected to a main data bus 22 so that it is coupled through the main data bus 22 to a CPU 1, a ROM 7, a main storage RAM 8 and a video RAM (VRAM) 9 to transfer and receive data thereto and therefrom. Secondly, an operation of this first embodiment will be described with reference to Fig. 1. Copyright digital information is encrypted or enciphered into digital information EDli and supplied with a recording medium such as a CD-ROM or an FDD or transmitted and supplied from a broadcast wave transmitter. In this copyright control system according to the first embodiment, the encrypted copyright digital information EDli is obtainable through a CD-ROM drive serving as one of option hardwares 6, a broadcast wave receiver or an FDD unit 3. The encryption/decryption hardware 11 reads out the obtained encrypted copyright digital information EDli through the sub-data bus 23 from the option hardware 6 or the FDD unit 3 and takes a decryption key K1 from the CPU 1, the decryption key K1 being attained through the FDD unit 3, an interface 5 or the option hardware 6 from a separate copyright control center. Further, the encryption/decryption hardware 11 decrypts the encrypted copyright digital information EDli using the decryption key K1 and makes the decrypted digital information stored in the main storage RAM 8 through the main data bus 22. Subsequently, as well as the prior example, in accordance with a program stored in the main storage RAM or the ROM 7 the decrypted digital information is expanded, or developed, and converted with the CPU 1 coupled through the main data bus 22 thereto and then displayed on a CRT unit (not shown) through the main data bus 22 and the video RAM 9. Furthermore, a description will be made hereinbelow of the case that, after the CPU 1 or the like accepts the decrypted digital information through the main data bus 22 to perform the display, edit and process, the edited and processed copyright digital information is reproduced and delivered through an HDD unit 2, the FDD 3 or the interface 5 for connections to external networks. The encryption/decryption hardware 11 reads out through the main data bus 22 the display, edited and processed copyright digital information D2i stored in the main storage RAM 8 and enciphers it using an encryption key K2 inputted therein from the CPU 1, thus producing an encrypted digital information ED2i. In this case, the encryption key K2 is obtainable from a separate copyright control center through the FDD unit 3, the interface 5 and/or the option hardware 6. Moreover, the encryption/decryption hardware 11 reproduces and transfers the encrypted copyright digital information ED2i through the sub-data bus 23 from the HDD unit 2, the FDD unit 3 or the interface 5 for connections to external networks. As described above, the copyright digital information is enciphered and supplied, while according to this first embodiment the enciphered copyright digital information can be deciphered using the decryption key K1 obtained from the separate copyright control center. In addition, the edited and processed copyright digital information can be enciphered using the encryption key K2 obtained from the separate copyright control center, and then reproduced and delivered. Second Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. In this embodiment the encryption/decryption hardware 11, the HDD unit 2, the FDD unit 3, a printer 4, the interface 5 and the option hardware 6 are connected to the main data bus 22 as shown in Fig. 2. In the Fig. 2 copyright control system, the encryption/decryption hardware 11 carries out the data input and output from and to the HDD unit 2, the FDD unit 3, the interface 5 and the option hardware 6 through the main data bus 22. In this respect, this embodiment differs from the above-described first embodiment. The operation is the same as that of the first embodiment. Third Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. In this embodiment the decryption processing and encryption processing of the copyright digital information are implemented by a software in place of the processes to be done by the encryption/decryption hardware 11. Fig. 3 is an illustration of an arrangement in the case that the processes of the encryption/decryption hardware 11 of Fig. 2 is performed with a software. In Fig. 3, designated at numeral 10 is an cipher processing program on the main storage RAM 8 which is designed to execute processes similar to those of the encryption/decryption hardware 11 in the first and second embodiments. In addition, the cipher processing program 10 implements the data input and output from and to the HDD unit 2, the FDD unit 3, the interface 5 and the option hardware 6 through the main data bus 22. For decryption, as shown in a flow chart of Fig. 4A the cipher processing program 10 reads out the obtained encrypted copyright digital information ED1i through the main data bus 22 from the option hardware 6 or the FDD unit 3 and deciphers it using the decryption key K1 obtained from the separate copyright control center and inputted in the cipher processing program 10 from the CPU 1, so that the deciphered digital information is stored in the main storage RAM 8 after passing through the main data bus 22. On the other hand, for encryption, as shown in a flow chart of Fig. 4B the cipher processing program 10 reads out, through the main data bus 22, the displayed, edited and processed copyright digital information D2i in the main storage RAM 8 and enciphers it using the encryption key K2 obtained from the separate copyright control center and inputted from the CPU 1 into the cipher processing program 10, thus producing the encrypted digital information ED2i. Further, the cipher processing program 10 / reproduces and delivers the encrypted digital information ED2i through the main data bus 22 from the HDD unit 2, the FD 3 or the interface 5 for connections to external networks. Fourth Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. This fourth embodiment relates to a more concrete arrangement of an encryption/decryption hardware 11. Fig. 5 is an illustration of an encryption/decryption LSI in the case that the encryption/decryption processing hardware 11 in the first or second embodiment is constructed with an LSI. In Fig. 5, a copyright control system is shown as including an encryption/decryption processing LSI 12, an encryption circuit 15, a decryption circuit 16, a buffer memory 17, and a bus interface 18 for connection to a main data bus or a sub-data bus 23. Furthermore, a description will be made in terms of an example where the encryption/decryption processing LSI 12 of Fig. 5 is applied to the encrypt ion/decryption hardware 11 of the first embodiment. The obtained encrypted copyright digital information EDli is read out through the sub-data bus 23 from the option hardware 6 or the FDD unit 3 and then stored in the buffer memory 17 of the encryption/decryption processing LSI 12 through the bus interface 18. Subsequently, the decryption circuit 16 reads out the encrypted digital information EDli from the buffer memory 17 and deciphers it using the decryption key K1 obtained from the separate copyright control center and inputted from the CPU I into the encryption/decryption processing LSI 12, before making the deciphered data again stored in the buffer memory 17. The digital information deciphered and returned to a plain text D1i is sent through the bus interface 18 to the main data bus 22 to be stored in the main storage RAM 8. Moreover, a description will be taken of the encryption processing of the edited and processed copyright digital information. The copyright digital information D2i, being displayed, edited and processed by the CPU 1 or the like and stored in the main storage RAM 8, is read out through the main data bus 22 and stored in the buffer memory 17 through the bus interface 18. The encryption circuit 15 enciphers the copyright digital information D2i, read out from the buffer memory 17 in a plain text form, by means of the encryption key K2 obtained from the separate copyright control center and inputted from the CPU I into the encryption/decryption processing LSI 12, thereby creating the encrypted digital information ED2i. This encrypted digital information ED2i is again stored in the buffer memory 17 by the encryption circuit 15. In addition, the encrypted digital information ED2i, converted into a ciphered text, is transferred through the bus interface 18 to the sub-data bus 23. The encrypted copyright digital information ED2i delivered to the sub-data bus 23 is reproduced and delivered from the HDD unit 2, the FDD unit 3 or the interface 5 for connections to external networks. Fifth Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. Although in the fourth embodiment the encryption/decryption LSI is used as the encryption/decryption hardware 11 in the first or second embodiment, it is also appropriate to realize it with an extended board. Fig. 6 is an illustration of an encryption/decryption processing extended board in which the encryption/decryption hardware 11 of the first or second embodiment is constructed with an extended board. In Fig. 6, numeral 13 represents an encryption/decryption processing extended board and numeral 19 denotes an ISA bus interface. The encryption/decryption processing extended board 13 performs the data input and output from and to other units through the ISA bus interface 19. In this respect, this embodiment differs from the above-mentioned fourth embodiment. The other portions are similar in operation to those of the fourth embodiment. Sixth Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. The encryption hardware 11 in the first or second embodiment can also be realized with an encryption/decryption processing PC card using a PCMCIA card, an IC card or t he like. Fig. 7 is an illustration of an arrangement of an encryption/decryption processing PC card. In Fig. 7, numeral 14 denotes an encryption/decryption processing PC card, numeral 20 signifies a PC card bus interface, and numeral 21 indicates a PC card controller. The encryption/decryption processing PC card 14 performs the data input and output from and to the other units through the PC card bus interface 20 and the PC card controller 21, which is different from the fourth embodiment. The other arrangement is similar in operation to the fourth embodiment. Seventh Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. Although in the encryption/decryption processing extended board 13 of the fifth embodiment the encryption circuit 15, the decryption circuit 16 and the buffer memory 17 are individually provided, the encryption/decryption processing LSI can be used in place of the encryption circuit 15, the decryption circuit 16 and the buffer memory 17, which exhibits the same effects. Eighth Embodiment This embodiment is not an embodiment of the invention, but useful for understanding the invention. Although in the encryption/decryption processing PC card 14 of the sixth embodiment the encryption circuit 15, the decryption circuit 16 and the buffer memory 17 are separately situated, the encryption/decryption processing LSI 12 can be used in place of the encryption circuit 15, the decryption circuit 16 and the buffer memory 17. This arrangement can also offer the same effects. Ninth Embodiment Although in the prior art, as described in previous embodiments, in the encryption/decryption processing LSI 12 the bus interface 18 is placed in common with respect to the main data bus 22 and the sub-data bus 23 it is also possible to separately provide a bus interface connected to the main data bus 22 and a bus interface coupled to the sub-data bus 23. In this case, the encryption/decryption processing LSI 12 demonstrates the same effect. As described above, according to this invention, an access to the encrypted copyright digital information EDli is possible only when the copyright control system deciphers it using the decryption key K1, and hence it is impossible to use the copyright digital information. without permission. In addition, the displayed, edited and processed copyright digital information D2i can be transferred, reproduced and stored only after the re-encryption by the encryption key K2, and therefore it is possible to prevent the use of the illegally transferred, reproduced and stored digital information.

Claims: A copyright control system comprising a central information processing unit (1) and a main data bus (22) directly connected to said central information processing unit (1), decryption means (11) which accepts encrypted copyright digital information to decrypt said encrypted digital information using a decryption key obtained from a copyright control center for primary utilisation of said encrypted digital information, wherein said decryption means (11) is coupled to said main data bus (22), and information processing means (2, 3, 4, 5, 6) to perform at least one of communication, broadcast, storage and copy of said encrypted digital information, wherein the information processing means (2, 3, 4, 5, 6) are coupled to a sub-data bus (23) and wherein the sub-data bus (23) is further coupled to said decryption means (11) and characterized in that the decryption means (11) is separately coupled to the main data bus (22) and to the sub-data bus (23). A copyright control system comprising a central information processing unit (1) and a main data bus (22) directly connected to said central information processing unit (1), encryption means (11) which accepts copyright digital information to encrypt said digital information using an encryption key obtained from a copyright control center for secondary utilisation of said digital information, wherein said encryption means (11) is coupled to said main data bus (22), and information processing means (2, 3, 4, 5, 6) to perform at least one of communication, broadcast, storage and copy of said digital information encrypted by said encryption means, wherein the information processing means (2, 3, 4, 5, 6) are coupled to a sub-data bus (23) and wherein the sub-data bus (23) is further coupled to said encryption means (11) and characterized in that the encryption means (11) is separately coupled to the main data bus (22) and to the sub-data bus (23). A copyright control system according to claim 2, characterized by decryption means (11) which accepts encrypted copyright digital information to decrypt said. encrypted digital information using a decryption key obtained from a copyright control centre for primary utilisation of said encrypted digital information wherein said decryption means (11) are coupled to said main data bus (22), wherein said information processing means (2, 3, 4, 5, 6) performs at least one of communication, broadcast, storage and copy of encrypted digital information wherein the sub-data bus (23) is further coupled to said decryption means (11) and wherein the decryption means (11) is separately coupled to the main data bus (22) and to the sub-data bus (23). The copyright control system according to claim 1 or 3, characterised by further.information processing means (7, 8, 9) to implement at least one of display, process and edit of said digital information decrypted by said decryption means, the further information processing means (7, 8, 9) being coupled to said main data bus (22). The copyright control system according to one of the preceding claims, characterised in that said decryption means (11) and/or said encryption means (11) is/are incorporated in an LSI circuit (12). The copyright control system according to one of claims 1 to 4, wherein said decryption means (11) and/or said encryption means (11) is/are incorporated in an extended board (13). The copyright control system according to one of claims 1 to 4, wherein said decryption means (11) and/or said encryption means (11) is/are provided in a PC card (14).

Inventors: KAMBE HIDETOSHI, SAITO MAKOTO, YAMAGISHI ATSUHIRO, KAMBE, HIDETOSHI, SAITO, MAKOTO, YAMAGISHI, ATSUHIRO, Kambe, Hidetoshi, c/o Mitsubishi Denki K.K., Yamagishi, Atsuhiro, c/o Mitsubishi Denki K.K.
Applicants: MITSUBISHI CORP, MITSUBISHI ELECTRIC CORP, MITSUBISHI CORPORATION, MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1996
Main classification: G06F12
IPC codes: H04L9, G06F1, G06F21, G06F12, H04N7, G09C1