Broadcasting contents protection system for HDTV has many difficult to apply file encryption technology that using the existing DRM systems. Therefore, this system has to be processed as accommodative about broadcasting contents format such as TS and PS and so on. Also, this system must support efficient encryption technology and random access mode. In addition, this system must have suitable key distribution mechanism in broadcasting environment. In this paper, we propose and implement encryption/key distribution scheme applicable to encoder/decoder without changing the existing MPEG system.