Authentication type security system

Description: TECHNICAL FIELD [Detailed description of the invention]

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INDUSTRIAL APPLICABILITY The present invention relates to a security system for preventing forgery and duplication of an object that requires authenticity determination, such as a prepaid card, a credit card, or an ID card.

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PROBLEM TO BE SOLVED: To generate signature data from original data using a signature generation rule and inspect the signature data using a signature inspection rule to obtain the original data as one method of a conventional security system. Authentication systems that verify authenticity are known. According to this system, a person who knows the signature inspection rule can inspect the signature data to confirm the authenticity of the original data. In addition, only a person who knows the signature generation rule can newly generate his / her own signed data or modify the data. Since this system can effectively determine the authenticity of data, a mechanism has been attempted to guarantee the authenticity of the data by attaching it to the object by sealing the data recording medium.

However, in this system, the data is analyzed by obtaining a plurality of samples of the signed data and the original data for an illegal purpose, the signature generation rule is deciphered, and the signature is added. It is not impossible to generate new data or falsify the data.

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PROBLEM TO BE SOLVED: To provide a highly safe security system by effectively preventing forgery and duplication of an object in view of the problems of the prior art. It is in.

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According to the present invention, the above object is a security system for preventing forgery and duplication of an object that requires determination of authenticity, and is individually set at the time of writing. It has an identification data storage area for storing and holding identification data based on the reference data, and a signature data storage area for storing and holding signature data for authenticating the identification data. The identification data or the data including the reference data is converted by a method according to the identification data or the variable generated by the reference data, and the authenticity determination is performed by converting the signature data into the identification data or the reference data. This is achieved by providing an authentication type security system characterized in that it is performed based on the authentication result of the identification data by the data obtained by reverse conversion by the method corresponding to the variable generated by.

As described above, the reference data obtained by reading by a predetermined machine or arbitrarily selected from the reference region where it is difficult to artificially manufacture the same one, or the identification data to be collated by the reference data. Since the authenticity of the identification data stored and held in the identification data storage area can be confirmed only by the signature data generated based on the basis and according to the variable generated from the reference data, for example, using a plurality of samples. However, it is extremely difficult to analyze this because each signature generation rule is different, and it is also extremely difficult to generate new signed data or falsify the data without knowing each of these signature generation rules. become.

In particular, only the signed data is determined by determining the authenticity based on the collation result between the data read from the reference area at the time of determination, the reference data included in the identification data or the signature data, and the above authentication result. Even if you simply dead copy, the authenticity of other objects is denied because the degree of agreement between the data read from the reference area at the time of judgment and the reference data is low, that is, even if it is illegally applied to other objects. It can be effectively prevented.

Further, by using the management data, which is the information necessary for managing the object, as the identification data together with the reference data, the management data can be used as information about the object and the signature generator. By separately collating with, it is possible to more effectively prevent the newly generated signed data and the falsification of the data.

Further, by assuming that the signature data is generated based on the compressed identification data obtained by compressing the identification data, the bit length required for processing can be suppressed and the time required for signature inspection can be shortened. can do.

As a reference region, it is difficult to artificially reproduce magnetic fibers randomly arranged in paper or resin, using uneven paper making, surface roughness of sheet material, etc. Moreover, any machine can be used as long as it can be detected with good reproducibility by a predetermined machine. As such an example, there are those disclosed in JP-A-6-168363, JP-A-52-3344, and JP-A-57-500851.

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BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a prepaid card to which the present invention has been applied. The card 1 is made of a polyester sheet 2, and the card stores identification data for storing management data for specifying the issuer, ticket type and card usage and reference data described later as identification data. A magnetic stripe 3 including a region, a perforated region 4 to be perforated as the frequency is consumed, and a reference region 5 in which magnetic fibers are randomly dispersed in the resin of the base sheet 2 are provided. The magnetic stripe 3 further includes a signature data storage area described later.

FIG. 2 shows a card reader to which the present invention has been applied. The card reader 10 has a built-in card transfer unit 12 including a motor-driven roller for taking the card into the slot 11 and ejecting the card after reading the data. Along the slot 11, a magnetic head 13 for reading the magnetic stripe 3 and an inductive magnetic head 14 for reading the reference region 5 are provided. Reference numeral 15 indicates a perforation unit for sequentially perforating the perforation region 4 of the card to indicate the consumption of frequency, and, if necessary, perforating the region to destroy the used reference region 5. Shown.

Next, with respect to FIG. 3, the signature data generation procedure of the card 1, that is, the card creation procedure will be described. First, a signal is mechanically read from the reference area 5 along the reading locus set on the card reader side, and this is combined with the management data A as the reference data F, and this is combined with the four 64-bit data blocks m.₁~ M₄The identification data M is written in the identification data storage area of the magnetic stripe 3. Next, the identification data M is subjected to a hashing process as shown in FIG. That is, first, the data block m₁, A fixed 64-bit data block h₀, H₀Two 64-bit data blocks h in combination with ₁, H₁ Is obtained. Next, the data block m₂, Those 64-bit data blocks h₁, H₁Two 64-bit data blocks h in combination with ₂, H₂ Is obtained. Repeating such a step four times, two 64-bit data blocks h₄, H₄ Is obtained. The finally obtained hashed data D has a data length of 128 bits.

As shown in FIG. 3, the hashed data D is combined with predetermined random data R to obtain, for example, 100 bits of input data Z according to the signature data length to be written. The affine transformation L, the bijection polynomial transformation P, and the affine transformation K are sequentially performed on the input data Z (Z Y X S), that is, the final signature data S is calculated by the signature generation function G. Is obtained and written in each storage area of the magnetic stripe 3 together with the above-mentioned identification data M. The entire data written on the magnetic stripe 3 in this way is referred to as the signed data W. At that time, the signature data storage area and the identification data storage area may be arranged independently of each other, but may be data encrypted by an arbitrary encryption method (not shown).

Here, the bijective polynomial transformation P transforms an arbitrary element Y on a finite field into a specific element X, and the difficulty of analyzing the signature generation rule is a multivariable on the finite field. It is based on the difficulty of solving simultaneous equations. Further, affine transformation is performed before and after the conversion so that the signature generation function G is not easily inferred from the signature inspection function V described later. Also, h in the hashing process₀, H₀It is possible to select any constant for .

Further, it is possible to select arbitrary constants for each of the affine transformations L and K in the signature generation function G and the bijective polynomial transformation P, but in the present application, each constant is selected from the reference data F. It can be set or changed according to the generated unique variable u. For this, for example, the table of the variable u and each constant may be referred to, or each constant may be generated from the variable u by using a separate function or the like. Actually, for example, the conversion algorithm of the bijective polynomial conversion P may be changed according to the variable u. In this way, various authentication systems can be formed, making it difficult to estimate signature generation rules. Further, since the random data R is concatenated at the time of signature generation, it is difficult to estimate the signature generation rule more effectively.

0018 When using this card 1, first, as shown in FIG. 5, the identification data M'of the signed data W'obtained from the magnetic stripe 3 is combined with the reference data F'and the management data A'. Separate into. Here, the reference data F'is compared with the reference data F "obtained from the reference region by the inductive magnetic head 14 to check the authenticity of the card and the presence or absence of forgery and tampering of the data, and the comparison. When it is confirmed that the result is appropriate, the identification data M'is subjected to the hashing process in the same manner as described above to obtain the hashed data D'. At the same time, the signature data S'of the signed data W'is obtained. Inverse conversion by the multivariate polynomial tapple Q (corresponding to the inverse conversion process of Z Y X S), that is, inverse conversion by the operation by the signature check function V. Generate u'and find the constant or inverse conversion algorithm used for the multivariate polynomial tapple Q. Separate the data obtained by the inverse conversion by this multivariate polynomial tapple Q into hashed data D "and random data R'. To do. By comparing the two hashed data D'and D obtained in this way, signature inspection is performed, and the presence or absence of forgery and falsification of the data is checked, and the comparison result is appropriate. Is confirmed, that is, only when the authenticity of the card is confirmed, the aptitude signal is output from the judgment device to provide a predetermined service according to the application. In addition to this, the management data A'is If it is confirmed that the management data A is stored in advance and is not shown, an aptitude signal may be output.

0019 Here, since it is substantially impossible to duplicate the same reference area as described above, dead copy of the card can be prevented. Further, the value of the reference data F "obtained from the reference region by the inductive magnetic head 14 is different every time it is read out due to various factors such as card transport, stop position error, degree of fouling, and deterioration of magnetism over the years. The authenticity of the card is checked based on whether or not the degree of coincidence is actually equal to or higher than a predetermined value. For example, the reference data F'is extracted from the identification data M'as magnetic data for the purpose of unauthorized use, and the reference area is Even if the reference data F "is read from 5 and the two are compared to clarify the relationship between the two, the relationship changes every time the reference data F" is read for the above reason. Therefore, even if a plurality of samples are used, the relationship is obtained. It is also extremely difficult to illegally create a card having an arbitrary reference area and create identification data M'corresponding to the reference data. Moreover, a signature is made based on the identification data. Since it is extremely difficult to create data as described above, it is also extremely difficult to falsify the data. Therefore, dead copy, forgery (replication), and data falsification of the card (object) are all extremely difficult. This makes it virtually impossible to cheat on the object.

In the above embodiment, the magnetic fibers are randomly dispersed in the resin of the base sheet 2 to form the reference region 5, but the reference region 5 is formed by simply forming a bar code for recording the variable u, for example. Also, if the application has a short recording / reading cycle, the reference area is not provided on the object side, the reference data is set on the reader / writer side, and this is changed periodically or irregularly. Is also good.

Further, as shown in FIGS. 3 and 5, a setting corresponding to the variable u of each constant of the above conversion, for example, a table of the variable u and each constant or a function for generating each constant from the variable u is externally provided. You may change the setting. This also applies when the conversion algorithm of the bijective polynomial conversion P is changed according to the variable u.

In addition, in the above embodiment, the object is, for example, an information storage card or an ID card, but it must be genuine, such as precious metals, securities, room or automobile keys whose unique value has been proved. It goes without saying that it can be arbitrarily applied to anything that needs to be proved.

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INDUSTRIAL APPLICABILITY As described above, according to the present invention, a complicated authentication system can be realized with a signature data having a relatively small bit length. Moreover, the processing time required for signature generation and signature inspection does not increase, and it is possible to operate at a speed and size that can be incorporated into a conventional card reader / writer, such as the size of the program and memory area required for algorithm construction. ..

The signature generation rule is set by converting the data including the reference data by a method according to the variable generated by the reference data to generate the signature data, and then performing the inverse conversion to authenticate the identification data. Since it changes depending on the reference data (variables generated by), it becomes extremely difficult to analyze the signature generation rule from the medium (object) and its reader / writer, and forgery and falsification of magnetic data that is relatively easy to duplicate. Can be significantly difficult. That is, even if a reader (signature inspection machine) is illegally obtained and analyzed, it is extremely difficult to estimate the signature generation rule based on the difficulty of solving a multivariate simultaneous equation on a finite field. Moreover, since this signature generation rule changes for each reference data (for example, for each object if the object has unique reference data), its analysis becomes extremely difficult, and the generation and modification of the signed data Can also be effectively prevented.

Furthermore, using the reference data read from the reference area where it is difficult to artificially produce the same thing, the reference data read at that time at the time of authenticity judgment is collated with the signed identification data. By doing so, it becomes extremely difficult to illegally duplicate the target card. Similarly, it is difficult to analyze the system from multiple card samples.

[Simple explanation of drawings]

FIG. 1 is a front view showing a prepaid card as an example of an object to which the system based on the present invention is applied.

FIG. 2 is a diagram showing an example of a card reader for a prepaid card.

FIG. 3 is a block diagram showing a procedure for creating a card based on the present invention.

FIG. 4 is a block diagram showing details of the hashing process in FIG.

FIG. 5 is a block diagram showing a procedure for authenticating and reading a card based on the present invention.

[Explanation of symbols]

1 Card 2 Base sheet 3 Magnetic stripe 4 Perforated area 5 Reference area 10 Card reader 11 Slot 12 Card transfer unit 13 Magnetic head 14 Inductive magnetic head 15 Perforated unit

Continuation of front page (72) Inventor Hiroyuki Matsumoto 3-10 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Within Japan (72) Inventor Masatake Ohno 3-10 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa From Japan Within the corporation