A copy protection circuit which can prevent the reproduction of the image / audio signal without changing the data structure in the digital transmission

摘要

The multiplexed stream information such as image / audio / data processed by the stream processing means 1 is separated into image / audio data and other data by the stream confirmation means 3, one of which is de-scrambling means 2 to the reproduction processing means 8 and 9 and the other is connected to a data bus such as a PC via the scramble key distinguishing means 5 and the I / The scramble key distinguishing means distinguishes the data format of the signal output to the data port in receiving the scramble key information of the scramble key extracting means (4), and discards information determined to be a scramble key for the image or audio, And outputs only the scramble key for blocking the image / sound.