Patent ID: 6892306

Claim:
A copyright protection protocol for protecting copyright of digital contents, said protocol including a header and the digital contents, said digital contents being encrypted, said header including key data for decrypting the digital contents, said key data being randomly generated in response to identity characters of a user transmitted to a host server from a terminal unit, wherein said terminal unit receives said protocol from said host server and replays said digital contents by decrypting the encrypted digital contents in response to the key data, wherein the header comprises a copyright support field for indicating whether the digital contents are under copyright protection, an unencrypted header field, and an encrypted header field; wherein the unencrypted header field comprises a copyright library version field, a digital content conversion format field, a field for indicating the code of a digital content provider, a key generation algorithm field, a digital content encryption algorithm field, a field for indicating the number of users sharing a personal computer, a field for indicating the number of users sharing a replaying device, a field for indicating user authorization information at the personal computer, and a field for indicating user authorization information at the replaying device; and wherein the field for indicating user authorization information at the personal computer and the field for indicating user authorization information at the replaying device comprise a field for indicating a hash value of a user key, and a field for indicating the size of the hash value generated by a hash algorithm, a field for indicating a resultant value of an encrypted temporary validation key, and a field for indicating the size of the resultant value of the encrypted temporary validation key, respectively.