JPH01108826A - Interface device - Google Patents

Abstract

PURPOSE:To ensure the safety of an interface device by operating a cryptographic means and a decoding means based on a program of a cryptographic/decoding program storage means. CONSTITUTION:The cryptographic/decoding program storage means 19 comprising a volatile memory stores a program decoded by a decoding means 18 for operating a cryptographic means 12 and a decoding means 14. Then based on the program of the cryptographic/decoding program storage means 19, the cryptographic means 12 and the decoding means 14 are operated and the cryptographic program is lost automatically against illegal decoding. Thus, the secrecy of the cryptographic method is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an interface device suitable for a system that sends verification data to the outside via a telephone line to confirm an individual.

(Prior art) A POS system connects a data input bag M (hereinafter referred to as PoS) for inputting sales data and an external computer that performs data aggregation and inquiries via a public telephone line. The system is configured to send sales data such as sales and credit data for credit sales to an external computer on the central side via a public telephone line.
The data stored in the O8 device is sent out periodically,
Further, credit data is sent at each point of sale.

By the way, sales data usually does not require a high level of confidentiality and raw data is transmitted directly, while credit data is directly related to personal property and privacy, so data stored on the card and PIN numbers are transmitted directly. The data is once encrypted by the interface device and sent to an external computer, and the data related to the inquiry result is also encrypted and sent back via the telephone line, decrypted by the ink face device, and outputted to the PO8 snowboard. .

Therefore, the confidentiality of credit data depends on the encryption method, but if the encryption program of the encryption method is decoded due to theft of the InkFace device, other similar InkFace devices may be There is a problem that the opportunity cannot be maintained.

(Purpose) The present invention was made in view of the above problem, and its purpose is to automatically execute the encryption program when the interface device main body is disassembled. An object of the present invention is to provide an interface device that maintains the confidentiality of an encryption method.

(Summary of the Invention) That is, the present invention is characterized by an interface device that encrypts input data using an encryption means and sends it out, and decrypts input encrypted data using a decryption means and sends it out. , a decryption program storage means storing an encrypted program for creating the encryption means and the decryption means, and a circuit means for storing a decryption key of the storage means, and for cutting off the electrical circuit by illegal disassembly. a volatile storage means that receives backup from a battery through a storage device; a decryption means that decodes a program stored in the storage means when the power is turned on; and an encryption-decryption program storage means that stores the decrypted program; The encryption means and the decryption means are operated based on the program in the encryption-decryption program storage means, and the encryption program is automatically erased in case of illegal decomposition.

(Example) The details of the present invention will be described below based on illustrated examples.

FIG. 1 shows an embodiment of the present invention, in which reference numeral 10 denotes an ink face device, for example, a card reader 21 for reading data stored in a credit card, etc., and inputting a password. Keyboard, Tatsu PIN
An output terminal 23 of a PO8 device M20 equipped with a pad 22 and an input terminal 11 are connected by a cable 3o.

Reference numeral 12 in the figure is an encryption means, and the credit data signal line 3 is inputted from the PO8 SOSO 2O via the cable 30.
1 is encrypted using the program described later and sent to the modem] 3
A decryption unit that decodes the encrypted data sent to and from the public telephone line C via the public telephone line C into the original data based on a program to be described later, and outputs it as the response data signal line 32 of the PO8 device 120. It is equipped with a converting means 14.

Reference numeral 15 denotes the aforementioned encryption/decryption program generation means, and reference numeral 16 in the figure denotes a decryption key storage means consisting of a volatile memory backed up by power from a battery 41 via a switch means 40, which will be described later. A decryption key for decrypting an encrypted decryption program stored in a decryption program storage means, which will be described later, is stored in the decryption key.

17 is a decryption program storage means, which is an encrypted means that can be decrypted by the above-mentioned decryption key]2
, and a program for operating the decoding means 14 which is encrypted and stored in a non-volatile memory. 18 is a program decoding means, and when the switch of the interface device j10, for example, the power switch 42 is turned on, the decoding program storage means 19 is for decrypting the program stored in encrypted form in 17 based on a decryption key;
It is an encryption/decryption program storage means consisting of a volatile memory, and stores a program for operating the encryption means] 2 and the decryption means 14, which has been decrypted by the decryption means 18.

FIG. 2 shows an embodiment of the above-mentioned switch means 4o, and reference numeral 40 in the figure indicates decoding key storage means]6.
A switch that is connected in series to the storage voltage terminals 16a and 16b of the memory storage voltage terminals 16a and 16b and a battery 41 that serves as a power source, and is closed when the lid 43 of the case 42 housing the interface device 11t107a is closed to supply power from the battery 41. It is configured as follows.

Note that the reference numeral 50 in the figure indicates a telephone connected to the modem 13.

In this embodiment, when the power switch 42 of the interface device W110 is turned on, the program decoding means 18
decrypts the data from the decryption program storage means 17 stored in an encrypted state based on the decryption key stored in advance in the decryption key storage means 16, and decrypts the data from the decryption program storage means 17 and the encryption means 1 and 2. A program necessary for the operation of the encryption means 14 is stored in the encryption/decryption program storage means 19-.

After completing such preparations, when credit data 31 such as data read by the card reader 21 or a password from the PIN pad 22 is input from the PO8 device 0, the encryption means 12 performs the encryption-decryption process. The encrypted data is encrypted based on the program in the encoded program storage means 19 and output to the modem 13. This encrypted credit data is sent via public telephone line C to an external computer (not shown).

The response data to this credit data is encrypted by an external computer and sent back to the interface device 10 via the public telephone line C. This encrypted response data is input to the decoding means 14 via the modem 13'. The decryption means 14 decrypts the original data based on the decryption program from the encryption-decryption program storage means 19 and sends it to the PO8O8 device 2 as a response signal line 32.
o Give out.

In such a state, if someone illegally disassembles the casing 42 of the interface device 10, the switch 4o is activated and the decoding key storage means 16 and the battery 41 are removed.
Since the electrical circuit between the
This results in loss of memory retention voltage and data loss.

Therefore, even if an interface device is obtained, there is no decryption key, so the program for data encryption cannot be read, and theft is impossible.

FIG. 4 shows a second embodiment in which a holding voltage is supplied to the decoding key storage means 16, and the reference numeral 30 in the figure is
With the cable mentioned above, two extra lines 33.
34, and jumper at terminal 23 on the PO8 snow cover 2o side! 135, and this line 33.
34 to the battery 41 and the decoding key storage means 16.
According to this embodiment, if an attempt is made to remove the ink face device 10 from the PO8 device 2o and steal it, the PO8 device 20 and the interface device 1o will inevitably be stolen. Since the connected cable 30 will be disconnected, the line supplying the holding voltage to the decoding key storage means 16 will be disconnected, and the decoding key stored here will disappear. become.

In this embodiment, the decoding key storage means 16 is constituted by a volatile memory, and when an unexpected situation occurs, the supply of holding voltage is cut off to erase the stored data, thereby reducing the current consumption of the backup battery. Although it is small, by configuring the decoding program storage means with a volatile memory and backing it up with the above-mentioned holding voltage circuit so that it can be volatilized in the event of an unexpected situation, it is possible to use an expensive non-volatile memory. It is possible to reduce costs by reducing the amount used.

(Effects) As described above, according to the present invention, in an interface device that encrypts input data using an encryption means and sends it out, and decrypts input encrypted data using a decryption means and sends it out, A decryption program storage means storing an encrypted program for operating the encryption means and decryption means, and a circuit means for storing a decryption key of the storage means and for cutting off the electrical circuit by illegal disassembly. The device comprises volatile storage means receiving backup from a battery, decryption means for decrypting the program in the storage means when the power is turned on, and encryption-decryption program storage means for storing the decrypted program. Encryption-
Since the encryption means and the decryption means are operated based on the program in the decryption program storage means,
In the case of illegal disassembly, the data encryption program and decryption program are automatically deleted, making decoding impossible, thereby ensuring the safety of the interface system.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an apparatus showing one embodiment of the present invention, and FIG.
The figure is a block diagram showing an embodiment of a means for supplying a holding voltage to the volatile memory of the same bag, FIG. 3 is a flowchart showing the operation of the snow making shown in FIG. 1, and FIG. It is a block diagram which shows another Example of a means. 10... Interface device 11... Terminal 20... PO8 device 23... Terminal 30... Connection cable 40... Switch means 41... Battery Fig. 1 Figure 4

Claims (1)

[Claims] In an interface device that encrypts input data using an encryption means and sends it out, and decrypts input encrypted data using a decryption means and sends it out, the interface device includes a program for operating the encryption means and the decryption means. A decryption program storage means stored in an encrypted form, a volatile storage means that stores a decryption key for the storage means, and receives backup from a battery through a circuit means that breaks the electric circuit by illegal disassembly; a decryption means for decoding the program in the storage means; and an encryption-decryption program storage means for storing the decrypted program; and a decoding means.