Patent ID: 8243567

Claim:
An optical disc having main information recorded thereon, the optical disc comprising: a spiral track; concave or convex recording marks on the spiral track; and a reflective film formed on the concave or convex recording marks, wherein the main information is for being decrypted using predetermined information, wherein the main information is recorded onto the optical disc by arranging the concave or convex recording marks on the spiral track and forming the reflective film on the concave or convex recording marks, wherein the main information is recorded onto the optical disc in a plurality of predetermined units, each predetermined unit of the plurality of predetermined units including at least address information and being continuously arranged with respect to another predetermined unit of the plurality of predetermined units in a direction of the spiral track, wherein the predetermined information is recorded based on first sub information and second sub information, wherein the first sub information is provided for each predetermined unit of the plurality of predetermined units, the first sub information varying for each predetermined unit of the plurality of predetermined units, wherein the first sub information is recorded by being superimposed on the main information by shifting the concave or convex recording marks, deforming the concave or convex recording marks, or altering a pattern of the concave or convex recording marks, wherein the second sub information is generated by scrambling the predetermined information using the first sub information that varies for each predetermined unit of the plurality of predetermined units, wherein the second sub information is recorded by being superimposed on the main information by changing a reflectivity of the reflective film formed on the concave or convex recording marks, and wherein, when the second sub information is generated by scrambling the predetermined information using the first sub information recorded in a first predetermined unit of the plurality of predetermined units, the generated second sub information is recorded in a second predetermined unit, of the plurality of predetermined units, that is continuous to and follows the first predetermined unit in the direction of the spiral track.