JPH0253153A - Ciphering system for memory medium - Google Patents

Abstract

PURPOSE:To decide a memory medium produced by its own company via a memory medium access means and at the same time to prevent the forgery of an outsider by ciphering the data confirming a memory medium production means via this means and through two types of ciphering parts. CONSTITUTION:A memory medium production means 1-1 owns two types of data including the number of a magnetic card issuing device to confirm a magnetic card which is produced by its own company. A confirmation data 1-4 and an original data 1-6 are ciphered by a 1st ciphering part 1-5 and a 2nd ciphering part 1-7 and written into a memory medium 1-2. A memory medium access means 1-3 trusts the amount of money, etc., serving as the read data 1-13-2 included in an original data 1-13 only when the ciphered sentence confirmation data 1-8 and the ciphered sentence data 1-9 are compounded by the 1st and 2nd decoding parts 1-10 and 1-11 and the coincidence is secured between both data. Thus the means 1-3 can decide whether the memory medium 1-2 like a telephone card, etc., is produced by its own company or not.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an encryption method for storage media related to logistics, transportation, finance, and others, and in particular, to an encryption method equivalent to a cash voucher such as a prepaid card (telephone card, orange card), etc. The present invention relates to a storage medium encryption method for encrypting data in a storage medium to improve security.

[Conventional technology]

Conventionally, this type of encryption system has typically used a set of encryption/decryption units for a storage medium that communicates information between storage medium creation means and storage medium access means.

Here, a conventional storage medium encryption method will be considered with reference to FIG. In the figure, storage medium creation means 3-I
In the step, the original data 3-2 is encrypted using the encryption unit 3-3. This encrypted cryptographic data 3-4 is written into the storage medium 3-5.

The storage medium access means 3-6 decrypts the encrypted data 3-4 written in the storage medium 3-5 into original data 3-8 using the decryption unit 3-7. This decrypted original text data 3-8 is updated.

The updated original text data 3-9 is stored in the storage medium creating means 3-1.
The encrypting unit 3-10, which is the same as the encrypting unit 3-3, is used to encrypt the cryptographic data 3-11 and write it into the storage medium 3-5.

[Problem to be solved by the invention]

In the conventional encryption method described above, the encryption section of the storage medium creation means and the encryption section of the storage medium access means are the same, so even if the original data is encrypted and the encrypted data is written to the storage medium, the following will occur. There are some drawbacks. For example, if the storage medium access means falls into the hands of a third party, the encrypted data on the storage medium is decrypted by the decryption unit of the storage medium access means, and a large amount of new storage media is stored in the encrypted data of the storage medium access means. Code data is created in the encryption department.

[Means to solve the problem]

The storage medium encryption method according to the present invention includes a storage medium creation means that has a first encryption section that encrypts authentication data that recognizes the storage medium creation means and a second encryption section that encrypts original text data. and.

A storage medium having ciphertext authentication data and the ciphertext data, a first decryption unit that decrypts the ciphertext authentication data of the storage medium, a second decryption unit that decrypts the ciphertext data, and the ciphertext data. and a storage medium access means having third and third encryption units for encrypting the original data in the storage medium again after updating the decrypted original data.

〔Example〕

Next, one aspect of the present invention will be explained with reference to the drawings.

FIG. 1 shows a schematic diagram of the configuration of an embodiment of the present invention.

In the figure, l-1 is a storage medium creating means that is a magnetic card issuing device such as a telephone card or orange card, 1-2 is a storage medium that is a magnetic card such as a telephone card or orange card, and ■-3 is a public telephone or Each represents a storage medium access means such as a ticket vending machine.

Storage medium creation means 1-I Fi has two types of data including a magnetic card issuing device number to confirm that the card is a self-issued magnetic card. One is authentication data 1-4
Well, the other one is original data 1-6. These two types of data are encrypted by separate encryption units. Part 1
The first encryption unit 1- encrypts the authentication data 1-4.
5 and the other is a second encryption unit 1-7 that encrypts the original data 1-6. The encrypted cryptogram authentication data 1-8 and cryptogram data 1-9 are stored in the storage medium 1-2, respectively.
will be written to.

The storage medium access means 1-3 uses the cryptogram authentication data 1-8 and the cryptogram data 1- to confirm whether the storage medium 1-2 such as a telephone card or an orange card is a card issued by the company. 9 each.

The authentication data 1-12 decrypted by the first decryption unit 1-10 and the second decryption unit 1-11 and the authentication data 1-13 in the original data 1-13 match in the determination unit 1-14. Only when the actual data in the original data 1-13! -15-2
(Figure 1(b)). Thus, the storage medium access means 1-3H.

The update unit 1-15 updates the amount, etc., and the updated original data 1-16 is encrypted by the third encryption unit 1-17, which is the same as the storage medium creation means 1-1, and written to the storage medium 1-2. .

Referring to FIG. 2, the operation when a newly created storage medium is read by the storage medium access means 1-3 that has fallen into the hands of a third party will be described.

Read the cryptogram authentication data and cryptogram data from the fake storage medium,
Decrypts ciphertext authentication data and decrypts ciphertext data.

Here, since the storage medium access means that has fallen into the hands of a third party does not have the first encryption unit for encrypting the authentication data, it is not possible to encrypt the authentication data on the new storage medium. As a result, a mismatch in authentication data occurs, and the storage medium access means considers the storage medium to be an unauthorized storage medium and interrupts the process.

〔Effect of the invention〕

As explained above, the present invention enables the storage medium access means to determine whether the storage medium is issued by the company by encrypting the data for authenticating the means for creating the storage medium into the storage medium using two types of encryption units. Even if the storage medium access means falls into the hands of a third party, it has only a small amount of encryption, which has the effect of preventing a large number of storage media from being forged.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a storage medium encryption system configuration according to an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the storage medium access means according to the present invention, and FIG. 3 is a conventional storage medium encryption method. FIG. 2 is a schematic diagram of the system configuration. In the figure, l-1 and 3-1 are storage medium creation means, l
-2°3-5 is a storage medium, and 1-3.3-6 is a storage medium access means.

Claims (1)

[Claims] 1. A storage medium creation means having a first encryption section for encrypting authentication data that recognizes the storage medium creation means and a second encryption section for encrypting original text data; a first decryption unit that decrypts the ciphertext authentication data of the storage medium, a second decryption unit that decrypts the ciphertext data, and an original text data obtained by decrypting the ciphertext data. 1. An encryption method for a storage medium, comprising: a storage medium access means having a third encryption unit for encrypting the original text data in the storage medium again after updating.