The invention discloses a digital copyright management method and device for protecting
digital content consumer privacy. The method comprises the following steps: randomly generating an encrypted
master key by utilizing the Chameleon
hash function, and generating a copyright
license; grouping the digital contents, then generating different symmetrical encrypted keys and cryptograph headers according to different groups of digital contents by adopting the Diffie-Hellman
key exchange technology, encrypting the digital contents to acquire digital cryptographs, and then, storing the cryptograph headers and the digital cryptographs into a
content server; and as required by users, decrypting from the cryptograph headers by utilizing the copyright
license to acquire the symmetrical encrypted keys of the authorized digital contents, and then, decrypting the corresponding digital cryptographs to acquire the required digital contents. The device comprises an authorized
server, a content serverand
consumer equipment. Under the same
security level, the invention can reduce the calculated amount, save the storage space and lower the requirements for network bandwidth.