Patent ID: 8249424

Claim:
An information recording medium for being able to record data by additional writing or re-writing, said information recording medium comprising: a groove track wholly wobbling at a frequency that is an even multiple of 140 kHz at the normal scanning velocity that is defined by the DVD-R standard or the DVD-RW standard, in order that 140 kHz at the normal scanning velocity is not detected by a reproduce apparatus, that uses a wobble detection method based on a self-correlation and comprising (i) a delay step of delaying a wobble signal for a half-period corresponding to 140 kHz at the normal scanning velocity; and (ii) an exclusive OR step of XORing the wobble signal and the delayed wobble signal; and control data zone included in the groove track for recording key information for encrypting the record data on the basis of the CSS (Content Scrambling System) encryption method.