초록 ▼

A data copyright management system comprises a database for storing original data, a key control center for managing crypt keys, copyright management center for managing data copyrights, and a communication network for connecting these sections. Data supplied from the database to users is encrypted

A data copyright management system comprises a database for storing original data, a key control center for managing crypt keys, copyright management center for managing data copyrights, and a communication network for connecting these sections. Data supplied from the database to users is encrypted and distributed. The users decrypts the encrypted data by crypt keys obtained from the key control center or copyright management center. To supply data to users, there are the following two methods: a one-way supplying of encrypted data to users by means of broadcasting or the like; and two-way supplying of encrypted data to users corresponding to users' requests. A crypt key system used for encrypting data uses a secret-key cryptosystem, a public-key cryptosystem or a cryptosystem combining a secret-key and a public-key and further uses a copyright control program to control data copyrights. When a user stores, copies, or transfers data, the data is encrypted by a crypt key different from a crypt key used for supplying the data. The former crypt key is supplied from the key control center or from the copyright management center, or generated by the copyright control program. The present invention can be applied to a data copyright management system for using not only single data but also a plurality of data supplied from a single database or a plurality of data supplied from a plurality of databases. Further, an apparatus to be used by the user to perform data copyright management is proposed.

대표청구항 ▼

[ We claim:] [1.] A data copyright management system for managing the copyright of data which is supplied as encrypted data from a database to a user, said data copyright management system including a database and a key control center, and using a secret-key and a copyright control program; comprisi

[ We claim:] [1.] A data copyright management system for managing the copyright of data which is supplied as encrypted data from a database to a user, said data copyright management system including a database and a key control center, and using a secret-key and a copyright control program; comprising:means for supplying a first secret-key and a second secret-key from a copyright management center to a primary user;means for decrypting said encrypted data to decrypted data by using said first secret-key by said copyright control program when said data is displayed;means for decrypting said encrypted data to decrypted data by using said first secret-key by said copyright control program when said data is edited;means for encrypting said data to re-encrypted data by using said second secret-key by said copyright control program when said data is stored;means for encrypting said data to re-encrypted data by using said second secret-key by said copyright control program when said data is copied;means for encrypting said data to re-encrypted data by using said second secret-key by said copyright control program when said data is transferred to said secondary user;means for decrypting said re-encrypted data again by using said second secret-key by said copyright control program when said re-encrypted data which has been stored is used;means for decrypting said re-encrypted data again by using said second secret-key by said copyright control program when said re-encrypted data which has been copied is used;means for decrypting said re-encrypted data again by using said second secret-key by said copyright control program when said re-encrypted data which has been transferred to said secondary user is used.