Electrical computers and digital processing systems: support – Multiple computer communication using cryptography – Particular communication authentication technique
Reexamination Certificate
2000-04-10
2001-08-07
Peeso, Thomas R. (Department: 2132)
Electrical computers and digital processing systems: support
Multiple computer communication using cryptography
Particular communication authentication technique
C713S155000, C713S156000, C713S168000, C713S169000
Reexamination Certificate
active
06272635
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for managing copyrights for using, storing, copying, editing, or transmitting digital data, particularly in multimedia applications.
2. Background Art
As database systems store increasingly larger amount of information, database systems are becoming popular in which many computers, used to store various types of data independently, are connected via communication lines to share the data.
In such a database system, the information handled up to this point has been conventionally coded information that can be processed by a computer, and that contains a relatively small amount of information and monochrome binary data, such as facsimile information at most It is not possible to handle data containing a relatively large amount of information, such as data for natural pictures or animation. A technique is under development for digital processing of picture signals other than binary data, handled only as analog signals in the past.
By digitizing the picture signal, it is possible to handle a picture signal, e.g., a television signal, by a computer. “Multimedia systems” is an emerging technology of the future capable of simultaneously handling the data handled by computers and digitized picture data.
Because picture data contains an overwhelmingly large amount of information compared with character data and audio data, it is difficult to store or transfer or process the picture data by computer. For this reason, techniques for compressing or expanding picture data have been developed. Further, several standards for compression/expansion of picture data have been established. For example, the following standards have been established as common standards: JPEG (Joint Photographic image coding Experts Group) standards for still pictures, H.261 standards for video conferences, MPEG1 (Moving Picture image coding Experts Group 1) standards for picture accumulation, and MPEG2 standards for current television broadcasting and high definition television broadcasting. By using these new techniques, it is now possible to transmit digital picture data in real time.
For analog data, which has been widely used in the past, the control of copyrights during processing has not been an important issue because the quality of the analog data deteriorates each time the data is stored, copied, edited, or transferred. However, the quality of digital data does not deteriorate when the data is repeatedly stored, copied, edited, or transferred. Therefore, the management and control of copyrights during processing of digital data is an important issue.
Up to now, there has been no adequate method for management and control of copyrights for digital data. It has been managed and controlled merely by copyright law or by contracts. In copyright law, only compensation for digital sound or picture recording devices has been prescribed.
It is possible not only to refer to the content of a database, but also to effectively utilize the data obtained from the database by storing, copying, or editing the data, and also transferring the edited data to the database with the edited data registered as new data. Further, it is possible to transfer edited data to other persons via a communication link or by a proper recording medium.
In a conventional database system, only character data is handled. However, in multimedia systems, sound data and picture data originally generated as analog data, are digitized and used as part of the database in addition to the other data in the database such as character data.
Under such circumstances, it is an important question to determine how to control copyrights of the data in the database. However, there are no means in the prior art for copyright management and control of such actions as copying, editing, transferring, etc. of data.
The inventors of the present invention proposed in Japanese Patent Application 1994-46419 and Japanese Patent Application 1994-141004 a system for managing the copyrights wherein the user is required to obtain a permit key from the key control center through a public telephone line, and in Japanese Patent Application 1994-132916 an apparatus for this purpose.
The inventors also proposed in Japanese Patent Application 1994-64889 a copyright management method applicable to both the primary use of a database system such as displaying (including audio output) and storing of digital data and the secondary use such as copying, editing, and transmission, including the real-time transmission of digital picture. This database copyright management method provides in the database system a program and copyright information required to control the copyright in addition to a permit key which is transmitted to the user. The copyright management program monitors and manages to prevent users from operating beyond the conditions of users' request or permission.
The inventors also proposed in Japanese Patent Application 1994-237673 a database copyright management system for specifically implementing the database copyright management method proposed in Japanese Patent Application 1994-64889 described above.
The system proposed in Japanese Patent Application 1994-237673 comprises a key management center that manages a crypt key K and a copyright management center that manages the database copyright. According to this system, all the data delivered from a database is encrypted by a first crypt key K
1
, and a primary user who wishes to uses data directly from the database requests from the key management center the key K corresponding to the specific usage by presenting information I
1
on the user to the center. In response to the primary usage request from the primary user, the key management center transfers the information I
1
on the user to the copyright management center. On receiving the information I
1
, the copyright management center transfers this information I
1
with a copyright management program Pc to the key control center. On receiving the copyright management program Pc, the key control center transfers the first crypt key K
1
and a second crypt key K
2
corresponding to the specific usage together with the copyright management program Pc to the primary user via a communication network. On receiving the first crypt key K
1
, the primary user uses this key to decrypt the data. The user subsequently uses the second crypt key K
2
to encrypt and decrypt data when storing, copying or transmitting the data.
In cryptographic systems, the use of the crypt key K to encrypt a plaintext M to obtain a cryptogram C is expressed as:
C=E(K, M)
and the use of the crypt key K to decrypt the cryptogram C to obtain the plaintext M is expressed as:
M=D(K, C).
These conventions are followed hereafter in the specification.
If data is copied to an external recording medium or transmitted without being stored, the first and second crypt keys K
1
and K
2
are disused. If the primary user wishes to use the data again, the first and second crypt keys K
1
and K
2
are re-delivered to the user from the copyright management center. The re-delivery of the second crypt key K
2
indicates that the data has been copied or transferred to a secondary user, and this is recorded in the copyright management center.
In requesting a secondary usage to the copyright management center, the secondary user presents the information I
1
on the primary user and information I
0
on the original copyright to the copyright management center. The copyright management center transmits to the secondary user a permit key Kp corresponding to the specific usage with a second crypt key K
2
(viewing permit key), a third crypt key K
3
(a permit key corresponding to the specific usage), and the copyright management program Pc which have been encrypted.
Typical encryption techniques include secret-key cryptosystem and public-key cryptosystem. The secret-key cryptosystem uses the same secret crypt key Ks for both encryption and decryption:
CmKs=E(Ks, M)
M=D(Ks, Cmks).
In the public-key
Armstrong Westerman Hattori McLeland & Naughton LLP
Mitsubishi Corporation
Peeso Thomas R.
LandOfFree
Data copyright management system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Data copyright management system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Data copyright management system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2437574