Patent ID: 8320225

Claim:
A reproduction-only recording medium in which data is recorded as recording unit blocks, wherein each recording unit block includes a main data area including a plurality of data frames, a first linking area of one frame preceding the main data area, and a second linking area of one frame following the main data area continuous with each other to form a data track by embossed pits, in which two consecutive recording unit blocks are separated by two frames of the first and second linking areas; and main data recorded in said main data area and linking data recorded in said linking areas in each of said blocks are scrambled by scrambling data generated by an identical system, wherein the identical system comprises a scramble circuit, wherein the scrambling circuit comprises a 16-bit shift register based on a polynomial Φ(x)=X 16 +X 15 +X 13 +X 4 +1, and exclusive-OR circuits, and each frame within a recording unit block is scrambled by the scrambling circuit by scrambling bytes generated by a random sequence with each of physical sector numbers as an initial value.