JPH0327489A - How to test the authenticity of documents - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention... credit card. Magnetic cards such as prepaid cards. Other items such as various cards, securities, stock certificates, and other important documents, computer cages, etc. may be forged.
It is used in the field of items that cannot be tampered with, and items that need to be determined whether they are authentic or not.

(Prior art) As a method of inspecting the authenticity of such documents. Conventionally, optical methods and magnetic reading methods are generally known. In other words. Optical methods include the color and shape of documents. There are methods for optically capturing visual features such as patterns drawn on documents and comparing them with genuine documents to determine authenticity, and methods for drawing specific marks and patterns on documents and optically detecting them. A method of reading it as a code or cipher is known. Also, as a method of reading magnetism. As is generally done with magnetic cards, a magnetic recording area is prepared on the document in advance, and numbers, characters, etc. are recorded in JIS format.
Convert it to standard code such as code and write it,
In some cases, a method is known in which the data is not encoded as is, but is encrypted using a conversion table or the like, written, read with a magnetic head, and code-converted again.

(Problem to be solved by the invention) However, with the recent development of printing technology and copying machines in optical methods, it has become relatively easy to produce items that look the same.
Even in the method of reading magnetism, if you obtain a magnetic head or a magnetic reader and read magnetic information. Even if the content is encrypted, there is a high risk of it being decrypted.

Note that Japanese Patent Publication No. 63-501250 discloses a method of mixing conductive fibers or the like and checking the authenticity of documents using microwaves.

(Means for Solving the Problems) The present invention has been made to make it difficult to forge or alter these documents.
A conductive material that affects radio waves such as ξυ waves and microwaves is mixed in a random form into a paper document such as T, and radio waves such as ξυ waves and microwaves are irradiated onto it. A unique random number is obtained for each document by measuring the reflection or transmission from the surface, converting the measured signal into a numerical value, and capturing it as a sequence of random numbers.The unique random number read by microwaves is used as a keyword. However, information that should originally be written in a document is converted using a conversion table or other method based on this keyword before being written, thereby making it difficult to forge or alter the document. .

(Example> below. The invention will be explained by examples.

FIG. 1 is a plan view showing an embodiment of the present invention in which stainless fibers are mixed into a magnetic card.

Figure 2 is a plan view showing the magnetic head and microwave sensor placed on the card, and Figure 3 is a graph of the output voltage of the microwave sensor when the card is scanned. Fourth
The figure shows a table showing how to create a random number sequence based on the output voltage.
Figure 5 is a table showing the correspondence between the data originally written and the code actually written. FIG. 6 shows tables each showing an example of a conversion table.

The seventh factor shows a plane view showing an example of application to a document without a magnetic recording section, which shows another embodiment of the present invention.

As shown in Figure 1. Stainless fibers 2 were randomly mixed into the magnetic card 1 in advance. Second
As shown in the figure, a microwave sensor 5 is applied from above and the magnetic card 1 is scanned. Then... The output voltage from the microwave sensor 5 draws a curve as shown in FIG.

If we set the minimum value of the voltage at this time to, for example, 3 4 0, and the maximum value to 9, divide it into 10 divisions, and set the scanning direction to, for example, 64 points. A random number sequence as shown in Figure 4 is completed. If we divide the voltage into two, we get a binary number represented by 0 and 1,
The number of points in the scanning direction can be determined as large or small depending on the purpose of use.

If the information originally written in the magnetic recording section 3 is ABCD... as shown in Figure 5, this should originally be written as a code 65, 66, 67.68... , If we use the random number sequence obtained from the microwave and add random numbers to each code value, the actual information to be written will be 65, 70, 69.71, etc.
・This makes it completely different from the original Denita.

When reading information later, the magnetic reading head 4 reads the magnetic information, and at the same time, the microwave sensor 5 can obtain the same random number sequence as when writing. Therefore, by reversing the writing procedure, first read out the magnetic information (
By subtracting each random number from the code), the original code value will appear and the original information will be obtained.

these are. Since the random number sequence that serves as a keyword is not magnetic information but microwave information, even if someone who does not know about it tries to read it, it will not be possible to decipher it with only a commercially available magnetic reading head, and even if a microwave sensor is available. Even if it is, the mounting position of the sensor. If the number of division points in the scanning direction and the number of divisions of the output voltage from the sensor are not known, it will not be possible to decipher it, making it extremely difficult to forge or alter documents such as power cards.

Also. Instead of adding the code originally written in FIG. 5 and the random number sequence obtained from the microwave, a conversion table as shown in FIG. 6 can also be used. That is, if a conversion table is stored in a ROM or the like in advance, a converted code can be obtained such as 71 when the originally written data is A and the random number is 0, and 67 when the data is B and the random number is 4. Although the concept of a conversion table is a common one, the keyword, random numbers, is not magnetic information. Since it is microwave information, it cannot be deciphered by a third party.

In addition to the method of allocating between the minimum value and maximum value of the output voltage from the microwave sensor 5 as in this embodiment, there is also a method. The output voltage from the microwave sensor 5 is subjected to Fourier transform to obtain the frequency spectrum. This can also be digitized into a random number sequence and used as a keyword.

Another example of FIG. 7 is securities. Stock certificate. An example of application to a document 6 without a magnetic recording section, such as a ticket, was shown.

Stainless fibers 2 are randomly mixed into the paper of documents such as securities in advance, and a microwave sensor is applied from above and scanned. Then, the output voltage from the microwave sensor draws a curve as shown in the third section, for example, as in Example 1. At this time, a random number sequence is obtained using the same procedure as in Example 1,
If the random number sequence 7 is written as is or converted using a conversion table or the like and written on one end of the document, it can be applied to documents without a magnetic recording section.

When checking the authenticity of documents. The number string written on one side of this document can be entered manually using a key, or the data can be read using a visual sensor or the like. This can be tested by comparing the random number sequence obtained from the microwave sensor.

Also, the number string to be written on one side of this document may be written using a bar code, or it may be written using infrared-sensitive ink or ultraviolet-sensitive ink to make it invisible. The security effect will be higher.

The conductor may be a metal fiber or the like, and for example, one disclosed in Japanese Patent Publication No. 63-501250 can be used.

(Effect of the invention) As explained above, according to the present invention, the same document can be reproduced.
Since it cannot be forged or altered, the authenticity of the document can be maintained.

[Brief explanation of drawings]

The drawings show one embodiment of the invention. Figure l is. FIG. 1 is a plan view showing an embodiment of the present invention in which stainless fibers are mixed into a magnetic card. Figure 2 is a plan view showing the magnetic head and microwave sensor placed on the card, Figure 3 is a graph of the output voltage of the microwave sensor when scanning the card, and Figure 4 is the output voltage. Figure 5 is a table showing how to create a random number sequence based on voltage, Figure 5 is a table showing how to convert data originally written to code to be actually written, and Figure 6 is a table showing an example of a conversion table. Show 7 8. The 7th one is. FIG. 6 shows a flat flash showing an example of application to a document without a magnetic recording portion, showing another embodiment of the present invention; FIG. The numbers in the diagram are 11 magnetic cards. 2- stainless fiber, 3- magnetic recording section, 4- magnetic reading head. 5-Microwave sensor. 61 Documents without a magnetic recording section such as securities,
71 represents a random number sequence, etc., respectively.

Claims (1)

[Claims] 1. In order to obtain a unique random number that is different for each document, materials such as conductors that affect radio waves such as millimeter waves and microwaves are randomly mixed into the front, back, or inner surface of the document and pasted together. , by irradiating radio waves such as millimeter waves or microwaves onto the parts incorporated by methods such as coating or printing,
A method for inspecting the authenticity of a document, characterized by measuring reflected or transmitted radio waves such as millimeter waves and microwaves, and using a numerical value of the measured signal as a random number sequence.