Method and apparatus for ciphering playback mode information for recording on record medium

A reproducing apparatus for reproducing data from a record medium, wherein contents of said record medium are selected from the group consisting of audio data, video data and a combination of audio and video data, said reproducing apparatus comprising:

• means for reproducing from said record medium modulated program data having said contents and a modulated data-converted bit sequence used for preventing unauthorized copying of the record medium contents;
• means for demodulating said modulated program data together with said data-converted bit sequence, wherein 16-bit coded program data is converted into 8-bit coded program data;
• means for error correcting said demodulated program data together with said data-converted bit sequence;
• means for separating header data at the leading end of each sector sectored in said record medium, wherein playback information having at least one item of copy managing information is separated from said header;
• means for reconverting said bit sequence with ciphering key information that comprises at least one of:
• a production number of the record medium;
• producer identification information;
• distributor identification information;
• identification information of a recording device used to record the program data on the record medium;
• identification information of an encoder used to encode the record medium contents prior to being recorded on the record medium;
• and, identification information of a device that produced the record medium;
• and
• means for de-sectoring program data in terms of a pre-set data volume as a unit composed of 2,048 bytes of data.