Patent ID: 6721887
Filing Date: 2004-04-13
Classification: G06F,H04L,H04N

Abstract:
A data copyright management method, comprising:obtaining a first secret-key and a second secret-key different from the first secret-key; decrypting the encrypted input data using the first secret-key to produce decrypted input data; editing the decrypted input data to produce edited data, the edited data including an editing process on the input data; encrypting the edited data with the second secret-key to produce encrypted edited data; and supplying the encrypted edited data as the encrypted input data to a next one of a plurality of users who repeats the above steps of obtaining, decrypting, editing, encrypting, and supplying, wherein the first secret-key of the next one of the plurality of users is the second secret-key of the user supplying the encrypted input data.