Patent ID: 7334134
Filing Date: 2008-02-19
Classification: G11B,H04N

Abstract:
1. A method configured for playing copy-protected and utilization-protected electronic audio and video media and their data contents, whereby the data contents of the electronic media are encrypted in such a way they cannot be completely played or displayed without the execution of cryptographic processes, wherein for playing purposes, a playback unit decrypts the data contents of electronic audio and video media that are supplied in entirely or partially encrypted or enciphered form by means of one or more “melody” keys for encrypting the data contents, the key being transmitted via a secure channel from an authentic source into the playback unit, and then the playback unit transfers these data contents from the digital domain into the analog domain in such a way that the data contents of the electronic audio and video media are not present at any point in time in unencrypted form as a digital data stream that can be copied, at least the following four pieces of information are transferred to a recipient via a transmission channel or via a medium together with actual audio and video information: 1) media data encrypted with the key melody: (media data) 2) the key melody encrypted with the “media” key: (key melody) 3) the “media” key encrypted with the “main” key: (med 4) the certificate of the “media” key or the digital signature of the “media” key created by the certification authority: sig