JPH01290028A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To ensure the high-degree secrecy by preparing a loadable/unloadable ciphered polynomial holding part and unloading and storing this holding part to inhibit such a case where the information ciphered and recorded on a medium are read out in the normal sentences. CONSTITUTION:The normal sentence data on the information recorded on a medium is applied to a normal sentence input terminal 1 and ciphered by a ciphering part 5 based on the contents of a ciphered polynomial holding part 3. This ciphered data is transmitted via a cipher output terminal 6 and recorded on the medium. Then the ciphered data read out of the medium is applied to a cipher input terminal 7 and turned into the normal sentences by the part 5 via the part 3 and transmitted through a normal sentence output terminal 2. Therefore the ciphered data is converted into the normal sentences and vice versa by the part 5 via the part 3. Thus it is impossible to read out the information ciphered and recorded on the medium in the form of the normal sentences as long as the part 3 consists partly of a connection part 4 is unloaded and stored. Then the perfect secrecy is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a removable rigid medium magnetic disk device, and more particularly to a removable rigid medium encrypted magnetic disk device that performs encrypted recording on the medium.

(Prior Art) Conventionally, this type of removable rigid medium encrypted magnetic disk device did not have a removable encrypted polynomial holding section.

(Problems to be Solved by the Invention) In the conventional removable rigid medium encrypted magnetic disk device described above, the encrypted polynomial holding section is not removable.
Although secrecy can be maintained between removable rigid medium encrypted magnetic disk drives with different encryption polynomials, secrecy cannot be maintained between the same removable rigid medium encrypted magnetic disk drives.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk drive that eliminates the above-mentioned drawbacks by making the encrypted polynomial holding section removable, and is configured to maintain complete confidentiality.

(Means for Solving the Problems) A magnetic disk device according to the present invention includes an encrypting section, an encrypted polynomial holding section, and a connecting section.

The encrypting section is for encrypting plaintext and converting the cipher into plain text, and the encrypting polynomial holding section is for holding the encrypting polynomial given to the encrypting section.

The connection section is for making the encrypted polynomial holding section detachable.

(Example) Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the encryption/decryption functional portion of a magnetic disk device according to the present invention. m1
In the figure, 1 is a plaintext input terminal, 2 is a plaintext output terminal, and 3 is a plaintext input terminal.
is an encrypted polynomial holding section, 4 is a connection section, 5 is an encryption section, 6
is an encryption output terminal, and 7 is an encryption input terminal.

Plaintext data of information recorded on a medium (not shown) is applied to the plaintext input terminal 1, encrypted by the encryption section 5 according to the contents of the encryption polynomial holding section 3, and output from the encryption output terminal 6. recorded on the medium. The encrypted data read from the medium is applied to the encryption input terminal 7, is decrypted by the encryption section 5 according to the encrypted polynomial holding section 3, and is sent out from the plaintext output terminal 2.

As is clear from the above explanation, encryption and plaintext conversion are performed in the encryption unit 5 according to the encrypted polynomial holding unit 3, so that the encrypted polynomial holding unit 3 and a part of the connection unit 4 are configured. By removing and storing the encrypted polynomial holding unit 3, it becomes impossible to read out the information encrypted and recorded on the medium as plain text.

In this embodiment, the connection section 4 has two signal lines, but it is clear that the number may be further increased depending on the encryption polynomial used.

(Effects of the Invention) As explained above, according to the present invention, the encrypted polynomial holding unit has a removable structure, so that when it is removed and stored, information encrypted and recorded on the medium can be stored. Since it is impossible to read out the data as plain text, it has the effect of making it possible to maintain a high degree of confidentiality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the encryption/decryption functional portion of a magnetic disk device according to the present invention. 1.2, 6.7... Pay 3... Encrypted polynomial holding section 4... Connection section 5 fist... Encryption section

Claims (1)

[Claims] an encryption unit for encrypting plaintext and converting the code into plain text; an encryption polynomial holding unit for holding an encryption polynomial given to the encryption unit; and the encryption polynomial holding unit. 1. A magnetic disk device comprising: a connecting portion for making the magnetic disk drive attachable and detachable.