KR100377352B1 - Method for carrying out electronic signature by hiding user information - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to an electronic signature method capable of controlling concealment and a computer readable recording medium having recorded thereon a program for realizing the method.

2. The technical problem to be solved by the invention

The present invention can be read by a computer recording a digital signature method capable of controlling the concealment constituting an electronic signature to be traced by the concealment control authority (court) when a problem with the concealed digital signature occurs and a program for realizing the method. To provide a record medium.

3. Summary of Solution to Invention

The present invention includes a first step of generating, publishing, and registering a system coefficient and a key for generating a hidden signature and a tracking factor in a user, a signing authority, and a stealth control authority; A second step of the signature authority performing a hidden signature generation operation with the user according to a request for generating a hidden signature including a public key of the concealment control authority from the user so that the user generates a hidden signature; And a third step in which the concealment control agency receives a tracking factor related to the concealment control from the signing authority to remove the concealment of the signature text and notify the signing authority of the signature.

4. Important uses of the invention

The invention is used in communication systems and the like.

Description

Method for carrying out electronic signature by hiding user information}

The present invention relates to an electronic signature method capable of controlling concealment and to a computer readable recording medium recording a program for realizing the method. In particular, the present invention guarantees a user's concealment of an electronic signature in a communication system and at the same time negates it. The present invention relates to an electronic signature method capable of controlling the concealment of the user in use and a computer-readable recording medium storing a program for realizing the method.

1 is an exemplary configuration diagram of a general electronic payment system.

In general, in the electronic payment system, the computer 101 of the user who wants to use the service, the computer 102 of the service provider who provides the service to the user, and the payment thereof, performs authentication and signature so that the electronic payment is made fairly. Server 103 of a signing authority (bank) and the Internet 104 connecting each computer to a network.

In the description of the present specification, a user's computer 101 is represented as a user, and a service provider's computer 102 is represented as a service provider, which is used when a user uses an electronic payment system using a computer. Is a case where the computer 101 of the service provider is abbreviated as a user, and the computer 102 of the service provider is represented by a person providing a service.

The development of open information and communication networks such as the Internet 104 and the increase of Internet users are inevitably forming new types of commerce markets such as electronic commerce, and the convenience is increasing rapidly. As a result, e-commerce has emerged as an important economic paradigm, and countries are competitively rushing to develop it. The electronic payment system has emerged as the most important element in such electronic commerce, and various attempts have been made to securely implement various current payment methods on the Internet. In particular, the electronic money system is recognized as the most important and powerful payment system that emerged to substitute current money on the Internet.

2 is an exemplary flow diagram of a conventional digital signature method.

Conventionally, in performing an electronic signature in an electronic money system or the like, first, a message M to be electronically signed by a user's computer 101 is generated and transmitted to a server 103 of a signer, that is, a signing authority (bank) (201), The signer performs the digital signature on message M using its private key (202). The user who has received the digitally signed message M verifies the signature of the signer using the signer's public key (203).

The electronic money system has the form of digital signature of the electronic money issuer (signature institution) on user identification data and money amount. Therefore, the electronic signature of the electronic money issuer plays a very important role, and the safety of the electronic money system as a whole depends on the safety of the electronic signature algorithm. Digital signature algorithm has been proposed in various ways and can be used in various fields such as electronic voting, electronic contract, electronic payment.

In Korea, KCDSA (Korea Certificate-based Digital Signature Algorithm) has been developed as the digital signature standard.

3 is a flowchart illustrating a conventional KCDSA digital signature method.

In the conventional KCDSA digital signature method, a user first generates a message M and transmits it to a signer (301), and the signer generates a digital signature (r, s) using the private key of the received message M. (302).

The signer then sends the message M and the signature text (r, s) to the user (303). The user receives the certificate, extracts the parameters necessary for signature verification from the received certificate (304), and verifies the signature of the signer for the message M based on the extracted parameters (305).

Such a KCDSA digital signature method has been conventionally presented as a national standard for use in an electronic money system, but this is only a guideline, and thus, there was a need to satisfy various needs of a user in actual use.

In addition, in the electronic money system, in order to protect the privacy of users, the digital signature technique was modified to use the hidden signature technique. This means that the relationship between the user and the user's purchases should not be traced by anyone. This means that banks and stores should not be able to track the users of electronic money even if they collaborate.

This will be described with reference to the drawings.

4 is a flow diagram of a conventional hidden digital signature method.

In a conventional hidden digital signature, the user first conceals the message M using a concealment factor r that only he knows (401). The user then sends 402 the message M 'concealed with the concealment factor r to the signer.

The signer receives the hidden message M ', performs a digital signature on the hidden message M' using its private key (403), and the signer transmits the hidden signed message Sign (M ') (404).

The user receives the hidden signed message Sign (M '), removes the hidden factor r from the received message Sign (M'), and obtains the signed message Sign (M) (405).

The hidden electronic signature method is accomplished in this way. However, since the concealed signature provides complete concealment, it can be used for illegal criminal activities such as money laundering, looting and illegal weapon purchase, and there is a problem in that the user cannot be tracked. Therefore, in order to prevent this, it is urgent to introduce an electronic signature scheme for controlling concealment under certain conditions.

The present invention has been proposed in order to solve the above problems, the electronic signature method capable of controlling the confidentiality constituting an electronic signature to be tracked by the concealment control authority (court) when the problem of the concealed electronic signature and It is an object of the present invention to provide a computer-readable recording medium having recorded thereon a program for realizing the method.

1 is an exemplary configuration diagram of a general electronic payment system.

2 is a flow diagram of a conventional digital signature method.

Figure 3 is a flow diagram of a conventional KCDSA digital signature method.

4 is a flow diagram of a conventional hidden digital signature method.

5 is a conceptual diagram of an electronic signature method capable of controlling stealth according to the present invention;

6 is a flowchart illustrating an electronic signature method capable of controlling concealment according to the present invention.

7 is a flow diagram of an embodiment of a hidden signature process between a signer and a user in accordance with the present invention.

8 is a flowchart illustrating an embodiment of a verification process of A ₁ ′, A ₂ ′ generated by a user according to the present invention.

9A and 9B are detailed flowcharts of one embodiment for the concealment removal process of electronic money according to the present invention;

* Explanation of symbols for the main parts of the drawings

101: user computer 102: service provider computer

103: server of signing authority 104: Internet

The method of the present invention for achieving the above object, in the electronic signature method capable of controlling the concealment applied to the communication system, the system coefficients for generating the hidden signature and the tracking factor generation in the user, the signing authority, and the concealment control authority And a first step of generating, publishing, and registering a key; A second step of the signature authority performing a hidden signature generation operation with the user according to a request for generating a hidden signature including a public key of the concealment control authority from the user so that the user generates a hidden signature; And a third step of receiving the tracking factor related to the concealment control from the signing authority, removing the concealment of the signature text, and notifying the signatory to the signing authority.

On the other hand, the present invention, a communication system having a large-capacity processor, a first function for generating, publishing and registering system coefficients and keys for the generation of hidden signatures and tracking factors in the user, signing authority, and concealment control authority; A second function for the signature authority to perform a hidden signature generation operation with the user in response to a request for generating a hidden signature including a public key of the concealment control authority from the user; And the concealment control agency receives a tracking factor relating to the concealment control from the signing authority, removes the concealment of the signature, and writes a program for realizing a third function of notifying the signing authority. Provide a record carrier.

In order to satisfy 'privacy' for the legitimate user or organization (hereinafter referred to as "user"), or "privacy protection," since a new signature method called concealment signature was introduced to protect the user's privacy. Various types of hidden signature schemes have been proposed. The concealed signature scheme can be largely divided into an "RSA" based scheme and an "ElGamal" based scheme using discrete algebra. In addition, the hidden signature scheme takes a message recovery scheme. This means that the data to be signed itself is a value that can verify the identity of the user (organization) or, in the future, the signing authority (hereinafter referred to as the "signature" (bank)) or other tracking authority (hereinafter referred to as the "tracking authority (investigation agency) Because the data can be tracked after the signature is used, the reconstruction type is used instead of the message addition type when signing the signing authority (bank).

Techniques based on the "RSA" approach were introduced early in 1982 after "D.Chaum" first proposed a hidden signature scheme. These concealment signature schemes use a "cut-and-choose" approach because the signature authority (bank) does not know even if a user (organization) sends a message other than the message for signature to the signature authority (bank). The valid messages were validated. However, the "cut-and-choose" method has a problem in terms of efficiency because of a large amount of communication and a lot of electronic money. To solve this problem, a new hidden signature method based on the discrete algebra problem is used.

The discrete algebra problem Is given by (y, g, p), and x is very difficult. To date, no polynomial time algorithm is known that can compute discrete algebra problems.

Most of the electronic money protocols use hidden signature schemes that exploit this discrete algebra problem. In addition, most of the methods using discrete algebra use "Schnorr" signature schemes to increase the efficiency of digital signatures.

In the present invention, by modifying the KCDSA, which is a domestic digital signature standard, which is a discrete algebra method, the user (institution) is concealed, and if necessary, the user can be trusted by a tracer (investigating agency) that has a fairness like a court. (Organization) We propose a message retrieval concealment signature technique that can track the identity and location of money.

Control of concealment is as follows.

The concealment control is performed by revealing a user identifier through a tracking factor included in a transaction statement when a user misuses it or reveals a unique value of a currency added when using a currency. This concealment control model can be divided into two parts. One is owner tracing, which identifies the owner of electronic money, and coin tracing, which identifies money withdrawals from banks, or to identify illegal circulation.

In owner tracking, the concealment control parameter allows the tracking agency (the investigative agency) to determine the owner of the money after the payment has been made. The purpose of this is to make it possible to track down even after the payment has been made, even if there is no illegal use such as double use or forgery or alteration, due to legal crackdowns on many currency distributions.

On the other hand, currency tracking, which is similar to tracking the serial number of a currency, is a currency tracking system where tracking functions are provided before the purchase of goods, and the tracking agency (investigative agency) checks the currency withdrawn from the bank and uses the money used to purchase the goods. You can link the withdrawn currency.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a conceptual diagram of an electronic signature method capable of controlling concealment according to the present invention.

5 illustrates an example of an electronic money system model using an electronic signature method capable of controlling concealment according to the present invention. That is, when the signing authority (bank) 53 signs electronic money and issues electronic money, the user (institution) 51 uses it. If the user (institution) 51 fraudulently used electronic money, and there is a request from the signing institution (bank) 53 or the legitimate request of the tracking institution (investigation agency) 54, In the same fair organization, the tracking parameters can be generated by the tracking factor, and transmitted to the tracking organization (investigation agency) 54 to be tracked.

This will be described with reference to the drawings.

First, the distribution of the secret signed electronic money is made by data communication through a network between the user (agency) 51, the store 52, and the signing authority (bank) 53. First, the user (institution) 51 withdraws the electronic money issued by the signing institution (bank) 53 (501), and the user (institution) 51 withdraws the electronic money to receive the service. Pay using the payment (502). The store 52 provides a service to the user (organization) 51 (503). The store 52 deposits the electronic money paid by the user (organization) 51 to the signing institution (bank) 53 (504).

This is done in a normal state, but when the user (institution) 51 pays the electronic money to the store 52, the store 52 knows that the electronic money is certified by the signing authority (bank) 53. The relationship between the paid currency and the user (organization) 51 is unknown. At this time, when the shop 52 or other tracking agency (investigation agency) 54 requests tracking, the secretion control agency such as the court 55 confirms this and removes the confidentiality of the user (organization) 51. Done. On the other hand, since concealment can be removed from a trusted institution such as the court 55, the court 55 is hereinafter referred to as a concealment control authority (court). Here, the concealment control agency (court) means that the parameters exchanged between the user and the signing authority (bank) to include the fair institution's parameters, such as the courts, in order to form electronic money. The concealment control authority (court) removes the user (agency) concealment factor using a secret key value that only the concealment control authority (court) has, so that the user identification value can be extracted from the electronic money. The process is as follows.

First, a tracking parameter is requested from the tracking agency (investigative agency) 54 to the concealment control agency (court) 55 (511), and the concealment control agency (court) 55 is responsible for the signature authority (bank). A command is made to (53) to request a tracer (512), and the signing authority (bank) 53 thus presents the control value to the concealment control authority (court) 55 (513). The concealment control authority (court) 55 removes the concealment of the user (institution) 51 using the electronic money by using the proposed control value (514), and the identification value of the tracking authority (investigation agency) ( 54). The tracking agency (investigation agency) 54 performs tracking using the provided identification value (516).

That is, in the case of general electronic money distribution, the electronic transaction such as information about the user and the path of the electronic money in circulation is made, and information generated by the signing institution (bank) 53 and the store 52 cannot be known.

However, if there is a problem with the distribution of electronic money, the location of electronic money in circulation can be tracked or used by eliminating the concealment of electronic money distributed by a trusted authority such as the concealment control agency (court) 55. The validity of the electronic money to be recognized can be recognized in the store, and for the electronic money classified as abnormal after being distributed, the user who distributed it can be confirmed by removing concealment.

6 is a flowchart illustrating an electronic signature method capable of controlling concealment according to the present invention.

The present invention provides a system coefficient and key generation process (601) for generating a hidden signature and a tracking factor, a hidden signature process (602) between a signer and a user, and tracking which exposes an identification value in case of fraudulent use of an electronic signature used in electronic money. Process 603 takes place.

First, a user (agency), signatory (bank), and concealment control authority (court) generate system coefficients and keys for concealment signature generation and tracking factor generation. Next, on an electronic money system with signatories (banks) and users (agencies) and trusted concealment controls (courts) to ensure fair concealment signatures, users (organizations) are sent from signatories (banks). Receive a signature that conceals your identity. This signature is made by combining the information presented by the user (organization), the information presented by the signing institution (bank), as well as the public key information provided by the concealment control authority (court) for the purpose of releasing the concealment.

When the user (organization) uses the digital signature in a way that is illegal, the signing authority (bank) provides the concealment control authority (court) with the parameters suggested by the user (organization) when generating the electronic signature. Figure out.

In addition, when a problem occurs during distribution of electronic money that can control concealment made in accordance with an embodiment of the present invention and the currency is to be tracked, the concealment control agency (court) receives information from the signer (organization) to solve the problem. Information to identify electronic money can be disclosed and the distribution location can be tracked. In addition, it is possible to prevent the circulation of electronic money for illegal use.

The system parameters used in this embodiment are based on the variables used in KCDSA, and parameters for hiding messages are added. The signature is extracted by the user (organization) from the parameters provided by the signing institution (bank). To generate the signature, the public key information disclosed by the concealment control agency (court) is used together.

Symbols displayed in the present invention are defined as shown in Table 1 below.

p 2 ^{| p | -1} <p <2 ^{| p |} , | p | = 512 + 256i (0≤i≤6), with (p-1) / 2q also being a prime or consisting of a product of primes greater than or at least q. q 2 divided by p-1 2 ^{| q | -1} <q <2 ^{| q |} , | q | = 128 + 32j (0 ≦ j ≦ 4). g ₁ h ^{(p-1) / q} mod p , 1 <h <p-1, g ₁ 1 User-selected hidden arguments. x Private signing key with 0 <x <q y Public verification key computed with I Configured to identify the user as a message to be signed, 0 <I <p k ' Disposable random number value of 0 <k '<q r As the first part of the signature Here, r 'is a value generated as follows using the disposable random number k' generated by the signer in the signing process. s As the second part of the signature, Extracted by verifier from In other words, signature (r, s)

The initial system coefficients and key generation process are described below.

First of all, in this process, each participating object generates parameters and processes the parameter information to be disclosed or transmitted before the signature is performed using the protocol.

ID It is a user identification value that is randomly selected by the user and kept secret. It is associated with the bank account number. I Created by the user and registered with the signer.

The parameters generated by the signing institution (bank) are explained in the following [Table 3].

p, q A prime number used by the KCDSA signature scheme, created and published by the signer g ₂ , g ₃ Produced by signer as source of primitives on GF (p), Galoa Field Private key Private signing key, where 0 <x <q Public key

The parameters generated by the concealment control agency (court) are described in the following [Table 4].

Private key Public key

7 is a flow diagram of an embodiment of a hidden signature process between a signer and a user according to the present invention.

Through the signing process, the user (agency) obtains a signature from the signing authority (bank). In this case, to protect the privacy of the user (organization), the KCDSA protocol is modified to generate a hidden signature, and in case of misconduct, the user can be detected by the concealment control authority (court). The agency creates a tracking factor and provides it to the signing bank. Of course, illegal circulation can also be tracked. In this case, the tracking factor value is generated by using a value disclosed by the signing authority (bank), an I value generated by the user (organization), and a public key value of the concealment control authority (court). Check if the tracking factor created by the user (organization) is created correctly.

This will be described through the flow of the drawings.

First, the user (organization) randomly v (in this case, ) Then, A ₁ 'and A ₂ ' to be used for generating the tracking factor are obtained and transmitted to the signing authority (bank) (701).

A ₁ 'and A ₂ ' can be obtained as shown in the following [Equation 1], [Equation 2].

Here, A ₁ ′ is a value obtained by performing a modulo operation with a power of v squared on the public key y _T of the hidden control authority (court) and p, which is a decimal value.

A ₂ 'is the I generated by the user (organization) to register the signatory (bank) to identify the user (organization), and g ₂ created and published by the signatory (bank) as a source of primitives on the Galloa Field, and also a primitive root of the Galois's field signing authority (bank) to create a user public and g ₃ (engine) is multiplied by the square v seunghan value randomly generated, a result value obtained by performing a modulo p.

Subsequently, the signing authority (bank) and the user (agency) perform a verification process that A ₁ ′ and A ₂ ′ are generated correctly (702). This is to be confirmed by the signing institution (bank) that has received this through the authentication process between the user (institution) and the signing institution (bank) as described in the following "Fig. 8".

This is based on Equation 3 below.

here, Proof for is performed to prove the trace factor generation without exposing v value.

After the signing authority (bank) has validated A ₁ 'and A ₂ ', That is, k ', which is a random value on the galoa field of q, is generated to generate r' as shown in Equation 4 below. Then, r 'is transmitted to the user (organization) (703).

Where y is the signer's public key.

User (organization) is a hidden factor to conceal its identification value I Wow Using the parameter and r 'transmitted from the signing authority (bank), the value of r to be used for the first part of the signature is calculated as shown in Equation 5 below (704).

Where I is an identification value of a user (agency) registered with the signatory (bank) by the user (agency), g ₁ is a publicly available parameter applicable to KCDSA, Is a hidden factor created by the user (organization), and r 'is a value generated by the signing institution (bank) and received by the user (organization).

The r-value obtained as described above is a hidden factor. In order to obtain the value of s, which is the second part of the signature, the hidden value I 'is obtained and transmitted to the signing authority (bank) (705). In this case, I 'is obtained as shown in Equation 6 below.

Next, the signing institution (bank) obtains s 'as shown in [Equation 7] using I' received from the user (institution) and transmits it to the user (institution) (706).

Here, x is a private key which is a private signing key of a signing authority (bank), k 'is a value obtained randomly by the signing authority (bank) as described above, and I' is hidden data received from a user (institution). Value.

The user (institution) extracts s to be used for the second part of the signature from the value s' obtained and passed by the signing institution (bank) (707). At this time, the user (organization) removes the hidden factor from s' and obtains the value of s to use it as the second part of the signature. s can be obtained as shown in Equation 8 below.

The user (institution) detects whether the signature of the signing institution (bank) is the correct signature using the value of s' extracted from the signing authority (bank) and the existing r value (708). . That is, it checks whether the signature (r, s) used in the signature is a valid value. This is explained together in describing the verification process of the generated signature.

Then, before constructing the final concealed signature, the user (institution) is randomly generated by the parameters p, y _T , g ₂ and publicly generated by the signatory (bank) and the user (institution) A ₁ ', A ₂ The tracking parameters A, A ₁ , A ₂ , and A ₃ to be used as trace factors by the concealment control agency (court) are generated based on v used to obtain (709). The generation of A, A ₁ , A ₂ , and A ₃ is performed in the same manner as in the following [Equation 9], [Equation 10], [Equation 11], and [Equation 12].

Here, I is a user identification value registered by the user (organization) with the signing authority (bank), g ₂ is a value generated and published by the signing authority (bank), and y _T is the public key of the concealment control authority (court). V is a value randomly generated by a user (organization) and used to obtain A ₁ 'and A ₂ '.

Based on the tracking parameter generated as described above, the user (organization) creates and uses the final signature by combining the hidden signature and the tracking factor as follows (710). The signature is made as follows.

Signature: [(r, s), A, A ₁ , A ₂ , A ₃ ]

At this time, validation of the tracking parameter is performed by the receiver and if it is not valid, the receipt of the signature is rejected. Validation is performed as shown in [Equation 13] below.

In generating the signature, the user (agency) and the signing authority (bank) perform a process of verifying whether the generated signature is correct. In the above embodiment of FIG. 7, a verification process that is not described will be described.

First, verify that the generated signatures (r, s) are valid.

The verifier can check the validity of the received signature through Equation (14).

Next, in the KCDSA hidden signature protocol, a signer view composed of information obtained by the signing authority (bank) while performing the signature protocol and an arbitrary message signature value (r, s) for proof of confidentiality to protect the confidentiality of the message signer is established. Given the hidden factor The existence of a unique pair of is demonstrated by Equation 15, Equation 16 and Equation 17 below.

That is, the only hidden argument pair given any view and any valid signature pair Is present.

This is summarized as follows.

And the only one satisfying Equation 15 below for any pair of (r, s), (I ', s', R') Is present.

From Equation 15 above, the following Equation 16 is satisfied. Select.

From the above equation, the following equation (17) holds Exists only.

8 is a flowchart illustrating a verification process of A ₁ ′ and A ₂ ′ generated by a user according to the present invention.

In order to verify A ₁ 'and A ₂ ' generated by the user (institution) and delivered to the signing institution (bank), the user (institution) first selects a random value on the galoa field of q. Generated, By using the following equations (18) and [19], a, b is obtained, and delivered to the signing institution (bank) together with the pre-generated A ₁ ', A ₂ ' (801).

Here, y _T is the public key of the concealment control agency (court), and is also used for A ₁ ′.

Here, g ₃ is a primitive source on the Galloa Field and is generated and published by a signing authority (bank), and is a value used for A ₂ ′.

After receiving the a, b, A ₁ ', A ₂ ', the signing authority (bank) obtains a random value w on the Galloa field of q and transmits it to the user (institution) (802).

The user (institution) obtains f and transmits it to the signing institution (bank) as shown in Equation 20 below (803).

Where w is the value passed from the signing authority (bank), v is the random value used by the user (agency) to find A ₁ ', A ₂ ', Is a random value used by the user (institution) to generate a and b previously delivered to the signing institution (bank).

The signing institution (bank) receives f from the user (institution) and performs the proof of the previously transmitted A ₁ ', A ₂ ' by using the following Equation 21 and Equation 22.

Here, y _T is a public key of the concealment control authority (court) known to the signing authority (bank), and f is a value received from the user (agency). a and A ₁ ′ are the values previously received by the signing authority (bank), and w is a value randomly generated and provided to the user (institution) by the signing authority (bank).

Where g ₃ is the value disclosed by the signing authority (bank) and f is the value transmitted from the user (organization). A ₂ 'and b are the values that the signing authority (bank) has already received from the user (institution), I is the identifier of the user (institution), and the signing authority (bank) is registered by the user (institution), g ₂ is a value disclosed by the signing institution (bank), and w is a value randomly generated by the signing authority (bank) and delivered to the user (institution).

9A and 9B are detailed flowcharts of an embodiment of a process for removing concealment of electronic money according to the present invention.

The concealment control is performed by revealing a user (organization) identifier through a tracking factor included in a transaction statement when a user (organization) fraudulently uses electronic money, or by revealing a currency unique identification value added when using a currency. This concealment control model can be divided into two parts. One is Owner Tracing, which identifies the owner of electronic money, and Coin Tracing, which identifies money withdrawals from banks. In owner tracking, the concealment control parameter allows the concealment controller (court) to determine the owner of the money after the payment has been made. The purpose of this is to enable the tracking of many money circulations even after the payment has been made, even if there is no illegal use such as double use or forgery or alteration due to legitimate crackdown requests. On the other hand, currency tracking, which is similar to tracking the serial number of a currency, provides the ability to track before buying. In the currency tracking, the tracking agency (investigative agency) can receive the tracking factor from the concealment control agency (court), check the withdrawn money with the bank, and link the withdrawn money to the one used for the purchase of goods.

9A is a flowchart illustrating an embodiment of a currency tracking process through concealment removal according to the present invention.

With the money tracking function, the tracking agency (investigative agency) can give the tracking function before the user uses the electronic money according to the order of the concealment control agency (court). That is, it concealed from the signature process, a user (organization), the A ₁ 'of the take-copy sent to the signing authority (bank) in between the electronic money is signature take-off process for use signing authority (bank) and a user (organization) St. control authority ( The court generates A ₁ and retransmits it to the signing agency (bank), so that the signing agency (bank) / tracking agency (investigative agency) tracks the currency through it. In other words, you can blacklist the currency so that the store can refuse to accept it, and you can track the currency by associating the used currency with the withdrawal currency.

This will be described according to the flow of the drawings.

First, the signing authority (bank) provides A1 'to the concealment control authority (court) among the withdrawal copies presented by the user (institution) (901).

The concealment control agency (court) calculates A1 from A1 'received from the signing authority (bank) as shown in [Equation 23] (902).

Here, A ₁ 'is a withdrawal copy delivered from the signing authority (bank), X _T is the private key or private key of the concealment control authority (court), y _T is a secret key X _T and signing authority (Banking) generated by using one g ₂ is generated by the public and a public key published.

The confidentiality of control authority (court) and transmits the extracted from A ₁ A ₁ 'received from the signing authority (bank) to the signing authority (bank) 903.

The signing authority (bank) distributes A ₁ transmitted by the concealment control authority (court) to the store where the electronic money is distributed in order to connect with A ₁ generated by the user (institution) and provided to the store in the payment process ( 904).

The store finds the corresponding electronic money by comparing it with A ₁ that the user (organization) provides to the store in the payment process (905).

This allows the user (organization) to track the payment regardless of the legality of the payment before purchasing the item using electronic money.

9B is a flowchart illustrating an embodiment of a user tracking process through concealment removal according to the present invention.

The user tracking process is a process of identifying a user (institution) after payment is established, and enables user (institution) tracking after a legal currency exchange is made. Through this function, the tracking agency (investigation agency) finds electronic money from the place where the user (organization) purchased illegal goods and tracks the user (organization) of the currency. This process is configured in addition to the deposit process, when the user (institution) pays the store. It is based on providing.

This will be described according to the flow of the drawings.

First, the signing authority (bank) extracts A ₁ and A ₃ from the transaction details deposited by the store and transmits it to the concealment control authority (court) (911).

Concealment control institutions (court) is A ₃ 'from the received A ₃ ( ) Is calculated and recalculated based on the obtained A ₃ ′ and the received A ₁ to obtain a user identification value I (912). The process of obtaining A ₃ 'is shown in Equation 24 below.

Here, A ₃ is a value received from a signing authority (bank), and A ₃ is obtained by multiplying I, a user (agency) identification value, by v squared with the public key y _T of the concealment control authority (court). This is the value obtained by modulating p by multiplying the value.

Using A ₃ 'thus obtained and A ₁ received from the bank, a user (organization) identification value I is obtained as shown in Equation 25 below.

The identity (I) obtained by the user (agency) is signed with A ₁ and A ₃ received from the signing authority (the bank) and encrypted with the signing authority (bank) public key. (913). At this time, the value encrypted and transmitted to the signing authority (bank) is made as shown in Equation 26 below.

As described through the above-described embodiments, the concealment signature control method capable of controlling confidentiality uses a public key of a third party in the process of generating a signature key between a user (agency) and a signing authority (bank), and uses the generated signature. If a problem occurs, the third party receives the information from the signer and removes the concealment. At this time, the removal of the concealment has a function of checking which user's electronic signature is issued after the digital signature is used and a function of checking where the electronic money containing the user's electronic signature is being distributed. The method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be apparent to those of ordinary knowledge.

As described above, the present invention not only prevents the user's information from being easily exposed by basically protecting the user's concealment in circulation of electronic money, but also by a fair third party when a problem occurs. Eliminating concealment has the effect of preventing fraud.

In addition, the present invention, by applying the domestic digital signature standard, the compatibility between various application protocols and easy to change to other protocols, and can be applied to a variety of protocols that must provide the user's privacy based on the secure process concealment signature scheme There is.

In addition, the present invention has the effect that it is possible to realize electronic commerce more efficiently and safely by providing the concealment as a basis.

Claims (14)

In the digital signature method which can control the concealment applied to a communication system, A first step of generating, publishing, and registering system coefficients and keys at a user, a signing authority, and a stealth control authority for generating a hidden signature and a tracking factor; A second step of the signature authority performing a hidden signature generation operation with the user according to a request for generating a hidden signature including a public key of the concealment control authority from the user so that the user generates a hidden signature; And A third step in which the concealment control agency receives a tracking factor related to the concealment control from the signing authority, removes the concealment of the signature, and notifies the signing authority Electronic signature method capable of controlling the concealment comprising a. The method of claim 1, The first step is, A fourth step of the user generating a user identification value I and registering it with the signing authority; The signing authority generates and publishes a first prime number (p) and a second prime number (q) to be used for signature, and the first and second primitives on the Galoa field (GF (p)) of the first prime number (p). A fifth step of generating and publishing data g ₂ and g ₃ and generating and publishing a public key y based on its private key x; And A sixth step in which the concealment controller generates and publishes a public key (y _T ) based on its private key (X _T ); Electronic signature method capable of controlling the concealment comprising a. The method of claim 1, The second step, The public key y _T of the concealment control authority, the first and second data g ₂ , g ₃ published by the signing authority, the identification value I of the user registered with the signing authority, and Generating a parameter to be used for generating a tracking factor for concealment control using any data v; The signing authority receives the tracking factor generation parameter from the user, the public key (y _T ) of the concealment control authority, the first and second data (g ₂ , g ₃ ) disclosed by the signing authority, and the signing authority A fifth step of confirming whether the identification value (I) of the user registered in the service is correctly generated; A sixth step in which the user receives a signature of the signing authority to generate a hidden signature for use by the user; A seventh step of verifying, by the user, that the correct signature has been received from the signing authority for the generated hidden signature; And Generation of the identification value (I) of the user registered by the user with the signing authority, the first data (g ₂ ) disclosed by the signing authority, the public key (y _T ) of the concealment control authority and the tracking factor generation parameters Eighth step of generating a trace factor by using random data (v) used in the construction and constructing a signature together with the pre-generated hidden signature Electronic signature method capable of controlling the concealment comprising a. The method of claim 3, wherein The fourth step, Any data that the user is on the second prime (Q) galoa field published by the signing authority ( Creating a ninth step; The user has the public key y _T of the concealment control authority and any data previously generated ( A tenth step of generating a first trace factor generation parameter A ₁ ′ using the following equation; And The first and second data (g ₂ , g ₃ ) published by the signing authority by the user, the identification value (I) of the user registered with the signing authority, and any data previously generated ( Step 11 to generate the second trace factor generation parameter (A ₂ ') using the following equation Electronic signature method capable of controlling the concealment comprising a. , The method of claim 3, wherein The fifth step, First random data, which is any value that the user is on the second prime (q) galoa field published by the signing authority, Creating a ninth step; The first random data previously generated by the user ), The first and second identification factors (a, b) are generated by using the public key (y _T ) of the concealment control authority and the second data (g ₃ ) disclosed by the signing authority (bank). A tenth step of delivering the first and second tracer parameter generation parameters (A ₁ ′, A ₂ ′) to the signing authority; Second random data, which is an arbitrary value on the second prime (q) galoa field, An eleventh step of generating) and delivering it to the user; Any data previously generated by the user ( ), The first random data ( ) And second random data received from the signing authority ( A twelveth step of generating a third identification factor (f) and transmitting it to the signing authority by A third identifier (f) transmitted by the signing authority, a public key (y _T ) of the concealment control authority disclosed, a first transmitted identifier (a) previously received, and second generated random data ( A thirteenth step of confirming whether the first trace factor generation parameter A ₁ ′ is generated correctly using; And The first and second data (g ₂ , g ₃ ) published by the signing authority, the received third identifier (f), the registered user identification value (I), the second random data generated ( Step 14 of checking whether the second trace factor generation parameter A ₂ ′ is correctly generated using the second identifier (b). Electronic signature method capable of controlling the concealment comprising a. The method of claim 3, wherein The sixth step, Third random data, which is an arbitrary value on the second prime (q) galloa field published by the signing authority which has confirmed that the tracer generation parameter has been correctly generated, ) And the first signature extraction parameter along with the signing authority's public key (y). Obtaining a ninth step) and transmitting it to the user; The first and second concealment factors for the user to conceal the identification value I of the user ( , ) Is generated and used together with the first signature extraction parameter r 'received from the signing authority (bank) to generate the first signature factor ( A tenth step of obtaining; The user has a first signing factor r and a second concealment factor ( ) Using the signature extraction cofactor ( Eleventh step of obtaining) and sending it to the signing authority; The signing authority uses the signature extraction cofactor I 'received from the user to generate a second signature extraction parameter ( Obtaining a 12) and transmitting it to the user; And A second signature argument to be used for the second portion of the hidden signature to be used by the user from the second signature extraction parameter s' passed from the signing authority, Step 13 to generate the hidden signature by extracting An electronic signature method capable of controlling concealment, characterized in that. The method of claim 3, wherein The seventh step, The concealment signature can be controlled by validating the secret signature (r, s) generated in the following manner to confirm whether the signature has been correctly received from the signing authority. Electronic signature method. The method of claim 3, wherein The eighth step, Generation of the identification value (I) of the user registered by the user with the signing authority, the first data (g ₂ ) disclosed by the signing authority, the public key (y _T ) of the concealment control authority and the tracking factor generation parameters The first tracking factor (v) using any data v used in Creating a ninth step; A second tracking factor (i) using the first data g ₂ published by the signing authority by the user and any data v used to generate the tracking factor generation parameter. Creating a tenth step; The third tracking factor (3) is used by using the identification value (I) of the user registered with the signature authority and any data (v) used to generate the tracking factor generation parameter. Creating a tenth step; A fourth tracking using the identification value (I) of the user registered by the user with the signature authority, the public key (y _T ) of the concealment control authority, and any data (v) used to generate the tracking factor generation parameters. factor( Creating a tenth step; And An eleventh step of constructing a signature text using the first, second, third and fourth tracking factors generated by the user with the previously generated hidden signatures r and s. An electronic signature method capable of controlling concealment, characterized in that. The method of claim 8, A twelfth step in which the receiver receiving the signature of the user validates the tracking factor of the signature as shown in the following equation to determine the reception of the signature; Electronic signature method capable of controlling the concealment further comprising a. The method according to any one of claims 1 to 9, The third step, Signature contact trace is the concealment requested for signature contact concealment removed to possibility of control authority is received providing a first tracking factor generation parameter (A ₁ ') from said signing authority second track included in the signed statement factor (A ₁ Creating a) to remove the concealment and notifying the signing authority of the fifteenth step; And The concealment controller, which is requested to remove the signature from the signature so that the user can be traced, is provided with the second tracking factor A ₁ and the fourth tracking factor A ₃ included in the signature from the signing authority. 16th step of extracting the identifier (I) of to remove the concealment and notifying the signatory Electronic signature method capable of controlling the concealment comprising a. The method of claim 10, The signature text, An electronic signature method capable of controlling concealment, characterized in that the signature is used for the distribution of electronic money during electronic commerce. The method of claim 11, The fifteenth step, A seventeenth request for removal of the concealment of the signature so that the signature authority can trace the signature by transmitting the first trace factor generation parameter A ₁ ′ of the trace factor generation parameters provided from the user to the concealment controller; step; The first trace factor generation parameter A ₁ ′ received by the signature authority from the signature authority is used together with the private key (X _T ) and the public key (y _T ) of the concealment control authority. An eighteenth step of generating a second tracer A ₁ as shown in equation; A nineteenth step of delivering the generated second tracking factor (A ₁ ) to the signing authority by the concealment control authority; And A twenty-stage step in which the signing authority tracks the signature by releasing a second tracking factor (A ₁ ) included in the signature issued by the user; Electronic signature method capable of controlling the concealment comprising a. The method of claim 11, The sixteenth step, The signature authority transmits the second and fourth tracking factors (A ₁ , A ₃ ) extracted from the circulation signature signature to the concealment control authority to request the removal of the signature secret for tracking the signature user. Step 17; By using the second and fourth tracking factors (A ₁ , A ₃ ) received from the signing authority with the private key (X _T ) of the concealment control authority, the concealment control authority receives a third expression as follows. Tracer generation parameter ( An eighteenth step of obtaining a user identification value I; And The signature authority (I) obtained by the concealment control authority is transmitted along with the second and fourth tracking factors (A ₁ and A ₃ ) previously transmitted to the signing authority (bank) to verify the user. 19th step to help Electronic signature method capable of controlling the concealment comprising a. In a communication system having a large capacity processor, A first function of generating, publishing, and registering system coefficients and keys at a user, a signing authority, and a stealth control authority for generating a hidden signature and a tracking factor; A second function for the signature authority to perform a hidden signature generation operation with the user in response to a request for generating a hidden signature including a public key of the concealment control authority from the user; And A third function of receiving the tracking factor related to the concealment control from the signing authority, removing the concealment of the signature text, and notifying the signing authority of the signing authority; A computer-readable recording medium having recorded thereon a program for realizing this.