A drawing method according to an embodiment of the present disclosure includes, when performing drawing on a thermal recording medium that includes a light-transmitting member above a recording layer, obtaining information regarding the light-transmitting member, predicting an optical axis deviation of a laser beam in the recording layer from the information regarding the light-transmitting member, and calculating a correction amount from a result of the prediction of the optical axis deviation.

In an information recording device, when receiving an erase command by a receiver, a controller erases data of an erased area by overwriting data in an information area, to corrupt the data in the information area, using an erasing pattern. The erased area is specified by an erase start position and a size of the data to be erased on the optical disc. The data in the information area is arranged as partial data in a series of data arranged in a direction of internal parity of error correction so that correction is disabled in both of a correction processing by the internal parity of the error correction and a correction processing by external parity of the error correction when the data in the information area is overwritten using the erasing pattern.

In an information recording device, when receiving an erase command by a receiver, a controller erases data of an erased area by overwriting data in an information area, to corrupt the data in the information area, using an erasing pattern. The erased area is specified by an erase start position and a size of the data to be erased on the optical disc. The data in the information area is arranged as partial data in a series of data arranged in a direction of internal parity of error correction so that correction is disabled in both of a correction processing by the internal parity of the error correction and a correction processing by external parity of the error correction when the data in the information area is overwritten using the erasing pattern.

In an information recording device, when receiving an erase command by a receiver, a controller erases data of an erased area by overwriting data in an information area, to corrupt the data in the information area, using an erasing pattern. The erased area is specified by an erase start position and a size of the data to be erased on the optical disc. The data in the information area is arranged as partial data in a series of data arranged in a direction of internal parity of error correction so that correction is disabled in both of a correction processing by the internal parity of the error correction and a correction processing by external parity of the error correction when the data in the information area is overwritten using the erasing pattern.

In an information recording device, when receiving an erase command by a receiver, a controller erases data of an erased area by overwriting data in an information area, to corrupt the data in the information area, using an erasing pattern. The erased area is specified by an erase start position and a size of the data to be erased on the optical disc. The data in the information area is arranged as partial data in a series of data arranged in a direction of internal parity of error correction so that correction is disabled in both of a correction processing by the internal parity of the error correction and a correction processing by external parity of the error correction when the data in the information area is overwritten using the erasing pattern.

An optical recording medium includes a reflective layer, a first dielectric layer, a phase-change recording layer, and a second dielectric layer. The phase-change recording layer has an average composition represented by SbxInyMz, in which M is at least one of Mo, Ge, Mn, and Al, and x, y, and z are values in the ranges 0.70x0.92, 0.05y0.20, and 0.03z0.10, respectively, provided that x+y+z=1, the first dielectric layer includes a zirconium oxide-containing composite material or tantalum oxide, and the second dielectric layer includes a chromium oxide-containing composite material or silicon nitride.

A system may include a key management server configured to store encryption keys. The system may also include a storage device that includes a processor, a memory coupled to the processor, and an optical medium coupled to the processor. The processor may be configured to encrypt and write data to the optical medium based upon the encryption keys, the data having metadata associated therewith, store the metadata in the memory, and read selected encrypted data from the optical medium. The processor may also be configured to retrieve the metadata associated with the selected encrypted data, retrieve a respective encryption key based upon the retrieved metadata, and decrypt the selected encrypted data based upon the respective encryption key. The processor may further be configured to delete selected metadata from the memory in response to a delete instruction so that the respective data is unreadable.

Upon receiving an erase command for data recorded in a write-once optical disc, an information recording device corrupts data in an information area (synchronization signal in Run-in, frame synchronization signal, address information and the like), in an erased area on the optical disc, in which information necessary for synchronization of reproducing data by overwriting the data in the information area with an erasing pattern. The erased area is specified by an erase starting position and a size of data to be erased. In this way, the information recording device erases the data in the erased area.

Upon receiving an erase command for data recorded in a write-once optical disc, an information recording device corrupts data in an information area (synchronization signal in Run-in, frame synchronization signal, address information and the like), in an erased area on the optical disc, in which information necessary for synchronization of reproducing data by overwriting the data in the information area with an erasing pattern. The erased area is specified by an erase starting position and a size of data to be erased. In this way, the information recording device erases the data in the erased area.

An optical recording medium includes a reflective layer, a first dielectric layer, a phase-change recording layer, and a second dielectric layer. The phase-change recording layer has an average composition represented by SbxInyMz, in which M is at least one of Mo, Ge, Mn, and Al, and x, y, and z are values in the ranges 0.70x0.92, 0.05y0.20, and 0.03z0.10, respectively, provided that x+y+z=1, the first dielectric layer includes a zirconium oxide-containing composite material or tantalum oxide, and the second dielectric layer includes a chromium oxide-containing composite material or silicon nitride.