Information recording processing apparatus, information reproduction processing apparatus, information recording medium, information recording processing method, information reproduction processing method, and computer program

An information recording and/or reproduction processing apparatus is disclosed by which additional information such as copy protection information is recorded as encrypted data on an information recording medium and also a cryptographic key is recorded such that the difficulty in analysis thereof is promoted. Where additional information such as copy protection information is encrypted and recorded and also a cryptographic key for the encrypted additional information is recorded together, a seed is generated based on an error correction code set corresponding to the additional information. Then, a scrambling or bit position conversion process in which random numbers generated based on the seed are applied is executed for the cryptographic key data, and resulting cryptographic key data is recorded on an information recording medium. Upon such recording, the additional information is recorded as pit information while the cryptographic key data is recorded as wobble data. The cryptographic key has an increased difficulty in analysis and allows achievement of an efficient data reproduction process.