Apparatus and method for data security in an optical disk storage system

Abstract

An optical storage disk for use in an optical storage system includes a storage layer which is capable of being disrupted when a laser beam of sufficient intensity is focused thereon. The optical storage disk has a transparent substrate layer on one side of the storage layer and a lacquer layer on the other side of the storage layer. The disruptions provided by the laser beam are selected to provide human readable and/or machine readable patterns. To reduce the damage to portions of the optical disk other than the storage layer, the storage layer is exposed to the laser beam prior to curing, or prior to applying and curing the lacquer layer. The optical disk can be of the type with data written thereon during fabrication, or the disk can be of the type in which data can be impressed thereon after fabrication of the optical disk. The patterns on the optical disk can be in the form of optical bar codes. In one application of the present invention involving the type of disk on which data can be written after fabrication, the pattern resulting from application of the laser beam to the disk is read by an optical reading device and transferred to the disk in the data format. The resulting embedded characters are used, in conjunction with files stored on the medium, to provide security against unpermitted access to the files. In addition for writable optical storage medium, the embedded characters can be used to prevent inappropriate material from being stored on the optical storage medium