Patent ID: 7672454

Claim:
A computer-implemented method for copy protection of digital content, wherein at least a part of the digital content is an active part implemented as a computer-implemented process enabling execution of the digital content, comprising: storing in a computer readable storage medium digital content in a first area of the storage medium; choosing a plurality of reference storage blocks from at least another area of the storage medium; creating dependencies between the digital content and the reference storage blocks; accessing with a computer the digital content with the active part only after verifying an accuracy of the dependencies with a position of the reference storage blocks in the storage medium and a content of the reference storage blocks; dividing the digital content into content blocks; feeding a seed to a key stream generator for generating a key; encrypting a first content block with the generated key; calculating cover keys based on the key and the reference storage blocks for verifying the dependencies; and storing the cover keys and storage block indices of the reference storage blocks together with the encrypted digital content block in the storage medium.