Disk medium, information recording device and information reproducing device

摘要

A disk medium, an information recording device, and an information reproducing device are provided, which are capable of efficiently recording sub-information such as security data and, if the sub-information is set as the security information, enhancing a security performance. The disk is divided into a plurality of zones in radial directions. A logical zone count in each zone is obtained by dividing a total recordable frame count in each zone by a frame count in a unit logical zone. For example, a logical zone count N1z in a zone i is given