Method and apparatus for discouraging duplication of digital data

摘要

A method and apparatus for creating a machine-readable medium such as a CD or a DVD disc is disclosed. The disc includes encoded copy protection data that, when decoded and re-encoded, produces a tracking prevention sequence of bits that causes a duplicate disc (containing the re-encoded copy protection data) to temporarily lose tracking. The temporary loss of tracking is utilized to render the duplicated disc unusable by placing key data immediately following the encoded copy protection data.