Patent ID: 6021199
Filing Date: 2000-02-01
Classification: G11B,H04N

Abstract:
A motion picture data encrypting/decrypting method of encrypting digitally compressed/encoded motion picture data including an intraframe encoded image and an interframe predictive encoded image, thereby preventing illegal use of the motion picture data, comprising the steps of:performing scramble processing of calculating, of the digitally compressed/encoded motion picture data, the intraframe encoded image on the basis of a predetermined rule;storing the motion picture data including the intraframe encoded image having undergone the scramble processing in an optical disk as a program area of a data sequence constituted by a lead-in area, the program area, and a lead-out area, and storing a scramble rule representing a calculation rule for the scramble processing in the lead-in area;reading the motion picture data in the program area from said optical disk; andexecuting descramble calculation processing for the intraframe encoded image contained in the read motion picture data on the basis of scramble data, thereby decrypting the motion picture data, wherein the motion picture data sequence is constituted by a header portion and a data portion, and the header portion includes data representing a location of the intraframe encoded image having undergone the scramble processing.