KR102062377B1 - Method for encryption digitalsignature to blind signature - Google Patents

Abstract

A method for generating an electronic signature is disclosed. According to the present invention, the method for generating an electronic signature comprises the steps of: calculating a first electronic signature value constituting an electronic signature using a message; encoding the calculated first electronic signature value using a homogeneous cryptographic signature key; when a temporary electronic signature value calculated using the encoded first electronic signature value is received, calculating a second electronic signature value constituting the electronic signature by decoding the received temporary electronic signature value using the homogeneous cryptographic signature key; and generating an electronic signature for the message using the calculated first electronic signature value and the second electronic signature value.

Description

Encryption method for converting a digital signature to a hidden signature {METHOD FOR ENCRYPTION DIGITALSIGNATURE TO BLIND SIGNATURE}

The present disclosure relates to an encryption method for converting an electronic signature into a hidden signature, and more particularly, to an encryption method capable of converting a general digital signature scheme into a hidden signature scheme using a homogeneous encryption scheme.

Thanks to the development of electronic and communication technologies, various services that transmit and receive data between various devices are supported. Among these various services, a field such as Internet banking requires a process for confirming that a message has not been forged in a process of transmitting and receiving a message, and this process is referred to as an electronic signature.

This digital signature is an electronic form of data that is used to verify the identity of the signer and to indicate the person's approval of the contents of the data message. It can be divided into an operation, a signature operation for signing a message to be sent, and an operation for checking the authenticity of a message and a signature.

However, the electronic signature does not encrypt the message itself, allowing third parties to verify the message. That is, the electronic signature only proves that the person who has been written as the author has written the electronic document and that the content has not been tampered with in the transmission / reception process.

Recently, as the security of information is required in relation to the security of personal information, a method of using a hidden signature with anonymity added to an electronic signature is required.

Therefore, the present disclosure is designed to solve the above problems, and relates to an encryption method capable of converting a general digital signature scheme into a hidden signature scheme using a homogeneous encryption scheme.

In order to achieve the above object, the method for generating an electronic signature according to an embodiment of the present disclosure is to calculate a first digital signature value constituting the digital signature by using a message, the calculated first digital signature value; Encoding using a homogeneous cryptographic signature key, if a temporary digital signature value calculated using the encoded first digital signature value is received, decoding the received temporary digital signature value using the homogeneous cryptographic signature key Calculating a second digital signature value constituting the digital signature, and generating an electronic signature for the message using the calculated first and second digital signature values.

The calculating of the first digital signature value may include receiving a first random verification key from an external device, generating a second random verification key, receiving the received first random verification key and the generated first signature. Generating a third random verification key using a random verification key; and calculating the first electronic signature value using the generated third random verification key and the message.

In this case, each of the first random verification key and the second random verification key may be an element of a set having a prime order.

In the encoding, the calculated first digital signature value may be homogenized using the homologous signature key.

The homologous signature key may be calculated from a ring, which is a set in which addition and multiplication are defined between elements, and is closed for addition and multiplication.

In the meantime, the method for generating a digital signature may include transmitting the encoded first digital signature value to an external device, and receiving a temporary digital signature value calculated using the encoded first digital signature value from the external device. The temporary electronic signature value may be calculated by using a signature key, a first random signature key corresponding to the encoded first electronic signature value, and a first random verification key.

In this case, the calculating of the second digital signature value may include decoding the received temporary digital signature value using the homogeneous cryptographic signature key, and decoding the received temporary digital signature value and the second random verification key. Computing the second electronic signature value using a corresponding second random signature key.

Meanwhile, an electronic device according to an embodiment of the present disclosure calculates a first electronic signature value constituting an electronic signature using a communication device communicating with an external device, a memory storing a message, and the stored message, and calculating the calculated value. And a processor for encoding the first digital signature value using a homogeneous cryptographic signature key, wherein the processor is configured to receive the temporary digital signature value calculated using the encoded first digital signature value from the external device. Decode the received temporary digital signature value using the homogeneous cryptographic signature key to calculate a second digital signature value constituting the electronic signature, and use the calculated first digital signature value and the second digital signature value. A digital signature can be generated for the message.

In this case, the communication device receives a first random verification key from an external device, the processor generates a second random verification key, and uses the received first random verification key and the generated second random verification key. The third random verification key may be generated, and the first electronic signature value may be calculated using the generated third random verification key and the message.

In this case, each of the first random verification key and the second random verification key may be an element of a set having a prime order.

Meanwhile, the processor may homogeneously encrypt the calculated first digital signature value using the homogeneous cryptographic signature key to encode the calculated first digital signature value.

The homologous signature key may be calculated from a ring, which is a set in which addition and multiplication are defined between elements, and is closed for addition and multiplication.

Meanwhile, the communication device transmits the encoded first digital signature value to the external device to an external device, and receives a temporary digital signature value calculated using the encoded first digital signature value from the external device, The temporary digital signature value may be calculated through a signature key, a first random signature key corresponding to the encoded first digital signature value, and a first random verification key.

In this case, the processor decodes the received temporary digital signature value using the homogeneous cryptographic signature key, and uses the second random signature key corresponding to the decoded temporary digital signature value and the second random verification key. The second electronic signature value may be calculated.

According to various embodiments of the present disclosure as described above, since the message proceeds to the homogeneous encryption state when generating the signature, there is a concealment of the message. In other words, it is possible to convert any electronic signature into a hidden signature. In addition, the size of the signature is the same as the existing digital signature, and the time required for verification is the same as the existing digital signature scheme.

1 is a view for explaining the structure of a network system according to an embodiment of the present disclosure;
2 is a block diagram illustrating a simple configuration of an electronic device according to an embodiment of the present disclosure;
3 is a block diagram illustrating a specific configuration of an electronic device according to an embodiment of the present disclosure;
4 is a view for explaining a digital signature generation operation according to the present disclosure;
5 is a sequence diagram illustrating a signature protocol according to an embodiment of the present disclosure;
6 is a view for explaining a method of generating an electronic signature in a first electronic device of the present disclosure;
7 is a diagram for describing a control method of a second electronic device of the present disclosure.

Hereinafter, the present disclosure will be described in detail with reference to the accompanying drawings. The information (data) transmission process performed in the present specification may be applied to encryption / decryption as needed, and in this specification and the claims, the expressions describing the information (data) transmission process are all encrypted / decrypted even if not mentioned otherwise. It should also be interpreted to include cases. In this specification, expressions of the form "transfer from A to B" or "A receives from B" include those transmitted (delivered) or received with other mediators in between, and necessarily from A to B. It does not represent only what is directly transmitted (delivered) or received.

In the description of the present disclosure, the order of each step should be understood to be non-limiting unless the preceding step is to be performed logically and temporally prior to the later step. That is, except for the exceptional cases described above, even if the process described as the following step is performed before the process described as the preceding step, the nature of the disclosure is not affected and the scope of rights should be defined regardless of the order of the steps. And as used herein, "A or B" is defined to mean not only selectively indicating any one of A and B, but also including both A and B. In addition, the term "comprising" in this specification has the meaning encompassing further including other elements in addition to the elements listed as containing.

The specification describes only essential components necessary for the description of the present disclosure, and does not refer to the components not related to the nature of the present disclosure. And it should not be interpreted in an exclusive sense that includes only the components mentioned, but in a non-exclusive meaning that may include other components.

The mathematical operations and calculations of each step of the present disclosure described below may be implemented by computer operations by known coding methods and / or codings suitable for the present disclosure to perform the operations or calculations.

The specific equations described below are described by way of example in a number of alternatives, and the scope of the present disclosure should not be construed as limited to the equations mentioned herein.

Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

1 is a view for explaining the structure of a network system according to an embodiment of the present disclosure.

Referring to FIG. 1, a network system may include a network, a plurality of electronic devices 100-1 and 100-2, and a server device 200.

The electronic devices 100-1 to 100-2 may be implemented in various types of devices such as smart phones, tablets, game players, PCs, laptop PCs, home servers, kiosks, and the like. It can also be implemented.

The first electronic device 100-1 may generate various keys for electronic signature. In detail, the first electronic device 100-1 may perform a key generation algorithm and may generate a signature key required for the electronic signature process and a verification key for verification. Here, the key generation algorithm is an algorithm for generating a signature key and a verification key, such as a Schnorr signature.

The verification key generated by the first electronic device 100-1 may be provided to the server device 200 or the like through a network. Here, the signing key is a key used when signing a message and may be referred to as a secret key. The verification key is a key used when performing verification on the generated signature and may be referred to as a public key. The signing key is a key used when encrypting (or encoding) a message and may be referred to as a secret key.

In addition, the first electronic device 100-1 may generate information necessary for a signature protocol process and provide the generated information to the second electronic device 100-2. In detail, the first electronic device 100-1 may perform a part of an operation of a signature protocol according to an embodiment of the present disclosure, such as generating a random verification key and generating a temporary electronic signature value.

The second electronic device 100-2 may perform a signature protocol operation. In detail, the second electronic device 100-2 may generate an electronic signature based on information provided by the first electronic device 100-1. A specific signature protocol method of the second electronic device 100-2 will be described later with reference to FIGS. 4 and 5.

The first electronic device 100-1 and the second electronic device 100-2 may be connected through a network. Here, the network may be implemented in various forms of wired / wireless communication networks, broadcast communication networks, optical communication networks, cloud networks, etc., and each device may be connected in a manner such as Wi-Fi, Bluetooth, Near Field Communication (NFC), etc. without a separate medium. have.

The server device 200 may receive an electronic signature generated by the second electronic device 100-2 and perform a verification operation on the received electronic signature. In detail, the server device 200 uses the verification key generated by the first electronic device 100-1 and the electronic signature provided by the second electronic device 100-2 to determine whether the electronic signature message and the authenticity of the signature are authentic. Can be verified

In FIG. 1, a plurality of electronic devices 100-1 to 100-2 is illustrated, but a plurality of electronic devices is not necessarily used, and one device may be used. For example, one electronic device may perform an operation of generating a secret key and a verification key and an operation of generating a signature for a message.

In the above-described example, the first electronic device 100-1 generates the secret key and the verification key. However, in the implementation, an electronic device or other device other than the first electronic device 100-1 generates the secret key and the verification key. After generating at least one of the keys, it is also possible to share with other electronic devices.

As described above, the network system according to the present embodiment proceeds by homogeneously encrypting a message during an electronic signature process, thereby preventing the contents of the message from being disclosed to an external device.

2 is a block diagram illustrating a simple configuration of an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 2, the electronic device 100 may include a communication device 110, a memory 120, and a processor 130. The electronic device 100 of FIG. 2 may operate as the first electronic device 100-1 of FIG. 1 and may also operate as the second electronic device 100-2 of FIG. 1. In the following description, it is assumed that the electronic device 100 can perform both operations of the first and second electronic devices. However, in the implementation, the electronic device 100 may perform only one operation.

The communication device 110 is formed to connect the electronic device 100 to an external device (not shown) and is connected to an external device through a local area network (LAN) and an internet network, as well as a USB ( Universal Serial Bus) ports or wireless communication (eg, WiFi 802.11a / b / g / n, NFC, Bluetooth) ports may be connected. The communication device 110 may be referred to as a transceiver.

에서 추출된 임의의 원소이고, 검증키는 군 G의 원소이다. 즉, 검증키는 소수 위수(prime order)를 가지는 군(group)(또는 집합)의 원소이다. The communication device 110 may receive a signature key from an external device, and transmit the signature key or verification key generated by the electronic device 100 to the external device. Here, the signature key (x) is a key used to perform the signature, and the verification key (y) is a key used to verify the signature. Where the signing key is a set

Is an element extracted from, and the verification key is an element of group G. That is, the verification key is an element of a group (or set) having a prime order.

In addition, the communication device 110 receives a first random verification key and a temporary digital signature value necessary for the signature process from an external device, or transmits the first random verification key and a temporary electronic signature value generated by the electronic device 100 to an external device. You can also send. Here, the first random verification key r1 is a verification key calculated through a random signature key k1 to be used as a random value. The first random signature key is selected from the same set as the previous signature key, and the first random verification key is An element of a group (or set) with a prime order.

The temporary digital signature value s' is a factor corresponding to the second digital signature value s constituting the digital signature, and is calculated as a homogeneous encrypted message rather than an actual message.

The communication device 110 may receive the encoded first electronic signature value or transmit the first electronic signature value encoded by the electronic device 100 to an external device. Here, the first electronic signature value is a value (e) constituting the electronic signature, and the encoded first electronic signature value means a first electronic signature value encoded with a homogeneous cryptographic signature key.

Here, the homologous secret secret key is a secret key used for homogeneous encryption, and is a value calculated from a ring which is a closed set for addition and multiplication between elements. As described above, the message is encrypted using the homogeneous encryption method and transmitted to an external device. Even though various arithmetic operations such as addition and multiplication are performed in the external device, the same result as performing the same operation on the message can be directly obtained. .

The communication device 110 may receive a message from an external device, and transmit the generated signature to the external device.

In addition, the communication device 110 may receive various parameters necessary for generating a cipher text from an external device. Meanwhile, in the implementation, various parameters may be directly input from the user through the manipulation input apparatus 150 described later.

The memory 120 is an element for storing O / S, various software, data, etc. for driving the electronic device 100. The memory 120 may be implemented in various forms such as RAM, ROM, flash memory, HDD, external memory, memory card, and the like, but is not limited thereto.

Memory 120 stores the message. Here, the message may be various credit information, personal information, etc. quoted by the user, or may be information related to a usage history such as location information and internet usage time information used in the electronic device 100.

The memory 120 may store the verification key, and when the electronic device 100 directly generates the verification key, it may store not only the signature key but also various parameters necessary for generating the verification key and signature key.

In addition, the memory 120 may temporarily store the values generated during the operation, and may store the last generated signature.

The processor 130 controls each component in the electronic device 100. The processor 130 may be configured as a single device such as a CPU, or may be configured as a plurality of devices such as a clock generation circuit, a CPU, and a graphics processor.

Meanwhile, in order to facilitate explanation, the operation of the processor 130 when the electronic device 100 operates as the first electronic device 100-1 will be described first, and then the second electronic device will be described first. An operation in the case of operating at 100-2 will be described.

에서 임의의 원소 x(서명키)를 추출할 수 있다. 그리고 프로세서(130)는 추출된 원소를 기초로 군 G의 원소(

)인 검증키를 생성할 수 있다. First, when operating as the first electronic device 100-1, the processor 130 may execute a program stored in the memory 120 to generate a signature key x and a verification key y required for an electronic signature. have. Specifically, the processor 130 is a set

You can extract any element x (signature key) from. In addition, the processor 130 may determine the elements of the group G based on the extracted elements.

You can create a verification key with).

를 만족하는 랜덤 값이고, 제1 랜덤 검증키는 상술한 군 G인 원소인

값을 의미한다. When the processor 130 is requested to start a signature protocol from an external device, the processor 130 generates a first random signature key k1 to be used as a random value and generates a first random verification key r1 corresponding to the first random signature key. The communication device 110 may be controlled so that the calculated first random verification key is transmitted to the external device. Here, the first random signing key is

Is a random value that satisfies, and the first random verification key is an element

It means the value.

When the processor 130 receives the encoded first electronic signature value e from the external device, the processor 130 receives the received first electronic signature value e , the signature key x generated above, and the first random signature key k1. ) Can be used to generate a temporary digital signature value ( s' ). In addition, the processor 130 may control the communication device 110 to transmit the generated temporary digital signature value s' to an external device.

Hereinafter, an operation of the processor 130 when operating as the second electronic device 100-2 will be described.

When operating as the second electronic device 100-2, the processor 130 may execute a program stored in the memory 120 to generate a homogeneous encryption secret key for homogeneous encryption. To this end, the processor 130 may first set a ring that is a set of polynomials having predetermined coefficients. Here, a ring is a set of additions and multiplications defined between elements and a closed set for additions and multiplications. Processor 130 may then calculate a homogeneous cryptographic secret key from the ring.

If the electronic signature is required, the processor 130 may request the protocol to start the first electronic device 100-1 to generate and transmit the first random verification key r1.

)를 생성할 수 있다. 여기서, 제2 랜덤 서명키는

를 만족하는 랜덤 값이고, 제2 랜덤 검증키는 상술한 군 G인 원소인

값을 의미한다. In addition, the processor 130 may calculate a first digital signature value e constituting the digital signature using the message m. In detail, when the processor 130 receives the first random verification key r1, the processor 130 generates a second random signature key k2 and a second random verification key r2, and generates the second random verification key r2. ) Is multiplied by the received first random verification key r1 to generate a third random verification key (

) Can be created. Here, the second random signing key

Is a random value satisfying the second random verification key,

It means the value.

The processor 130 may calculate the first electronic signature value e using the third random verification key r and the message m. In detail, the processor 130 may calculate the first electronic signature value e using Equation 1 below.

Here, e is a first digital signature value, m is a message, r is a third random verification key, and H is a hash function.

The processor 130 encodes the generated first digital signature value using a homogeneous cryptographic secret key. In detail, the processor 130 may homogeneously encrypt the first digital signature value e calculated using the homogeneous cryptographic secret key. In addition, the processor 130 may control the communication device 110 to transmit the encoded first electronic signature value e to the external device.

When receiving the temporary digital signature value s' from the external device, the processor 130 decodes the received temporary digital signature value by using a homogeneous cryptographic secret key (hsk) to form a second digital signature value (s) can be calculated. Specifically, upon receiving the temporary digital signature value s' calculated using the encoded first electronic signature value from the external device, the processor 130 receives the temporary digital signature received using the homogeneous cryptographic secret key hsk. value (s ') to the decoding and the decoded temporary digital signature value (s' calculates a second electronic signature value by using a second random signature key (k2) corresponding to a), a second random verification key (r2) Can be. In detail, the processor 130 may calculate a second electronic signature value by using Equation 2 below.

Where s is the second digital signature value, k2 is the second random signature key, s' is the decoded temporary digital signature value, k1 is the first random signature key, e is the first digital signature value, and x is the signature key.

The processor 130 generates the electronic signatures e and s for the message using the calculated first electronic signature value e and the second electronic signature value s. In addition, the processor 130 may control the communication device 110 to transmit the encrypted electronic signature to the external device.

In the meantime, although only a simple configuration constituting the electronic device 100 has been illustrated and described, various configurations may be additionally provided. This will be described below with reference to FIG. 3.

3 is a block diagram illustrating a specific configuration of an electronic device according to an embodiment of the present disclosure.

Referring to FIG. 3, the electronic device 100 of the present disclosure may include a memory 120, a processor 130, a communication device 110, a display 140, and a manipulation input device 150.

Since the communication device 100 and the memory 120 have been described with reference to FIG. 2, duplicate description thereof will be omitted. Also, the processor 130 has been described with reference to FIG. 2, and the descriptions of FIG. 2 are not repeated, and only the contents related to the configuration added to FIG. 3 will be described below.

The display 140 displays a user interface window for selecting a function supported by the electronic device 100. In detail, the display 140 may display a user interface window for selecting various functions provided by the electronic device 100. The display 140 may be a monitor such as an LCD, a CRT, an OLED, or the like, and may be implemented as a touch screen capable of simultaneously performing a function of the manipulation input apparatus 150 to be described later.

The display 140 may display a message requesting input of a parameter required for generating a homogeneous password secret key. In addition, the display 140 may display a message in which the encryption target selects the message. In the implementation, the encryption target may be directly selected by the user or may be automatically selected. That is, personal information requiring encryption may be automatically set even if the user does not directly select a message.

The manipulation input device 150 may receive a function selection of the electronic device 100 and a control command for the corresponding function from the user. In detail, the manipulation input apparatus 150 may receive a parameter for generating a homogeneous password secret key from a user. In addition, the manipulation input device 150 may receive a message to be encrypted from the user.

When the processor 130 receives a parameter required for the homologous secret key from the user, the processor 130 may generate a setting parameter based on the received parameter, and generate the homogeneous password secret key based on the generated setting parameter.

If an electronic signature is required for the message, the processor 130 may generate an electronic signature having a first electronic signature value and a second electronic signature value through cooperation with an external device through the above-described process.

As described above, the electronic device 100 according to the present embodiment performs the homogeneous encryption of the message when the electronic signature is performed in cooperation with the external device, thereby preventing the contents of the message from being disclosed to the external device. have. In addition, the generated electronic signature is the same as the existing electronic signature, and the time required for verification is also the same as the existing electronic signature.

4 is a diagram for explaining an operation of generating a digital signature according to the present disclosure.

First, the key generation algorithm will be described.

에서 임의의 원소 x(sk)를 추출하고, 추출된 원소를 기초로 군 G의 원소(

)인 검증키(vk)를 생성할 수 있다. Referring to FIG. 4, the first electronic device 100-1, which is a signer, may generate a signature key sk and a verification key vk required for an electronic signature. In detail, the first electronic device 100-1 is aggregated.

Extracts any element x (sk) from, and based on the extracted elements,

Can generate a verification key vk.

In this case, the first electronic device 100-1 may disclose the generated verification key vk through the network.

The signature protocol operation is described below.

The second electronic device 100-2 may encrypt the message using the same type secret key and provide the message to the first electronic device 100-1.

The first electronic device 100-1 generates an encrypted signature σ using the provided encrypted message and the signing key sk, and generates the generated encrypted signature σ . -2) can be sent.

When the second electronic device 100-2 receives the received encrypted signature (), the second electronic device 100-2 decrypts the received encrypted signature using a homogeneous cryptographic secret key (hsk), and decrypts the decrypted signature and message with the electronic signature. May be sent to the verifier 200.

More specific signature protocol operations of the first electronic device 100-1 and the second electronic device 100-2 will be described later with reference to FIG. 5.

가 성립하는지를 확인하고, 성립한다면 1을 출력하고, 성립하지 않으면 0을 출력할 수 있다. Hereinafter, referring to the verification operation, the server device 200, which is a verification device, may verify the integrity using the provided electronic signature and the public verification key vk. Specifically, the server device 200 calculates the following Equation 3 in the same manner as the existing schnorr signature,

Can be verified, and if it does, 1 can be printed, or 0 if it is not.

Where g is an element of group G, s is a second electronic signature value, y is a verification key, and e is a first electronic signature value.

5 is a sequence diagram illustrating a signature protocol according to an embodiment of the present disclosure.

Referring to FIG. 5, when an electronic signature is required, the second electronic device 100-2 requests the first electronic device 100-1 to start a signature protocol.

를 만족하는 랜덤 값이고, 제1 랜덤 검증키는 상술한 군 G인 원소인

값을 의미한다. The first electronic device 100-1 that is requested to start the signature protocol generates a first random signature key k1 to be used as a random value and calculates a first random verification key r1 corresponding to the first random signature key. Can be. Here, the first random signing key is

Is a random value that satisfies, and the first random verification key is an element

It means the value.

The first electronic device 100-1 may transmit the calculated first random verification key to the second electronic device 100-2.

)를 생성할 수 있다. 여기서, 제2 랜덤 서명키는

를 만족하는 랜덤 값이고, 제2 랜덤 검증키는 상술한 군 G인 원소인

값을 의미한다. Upon receiving the first random verification key, the second electronic device 100-2 generates a second random signature key k2 and a second random verification key r2, and generates the second random verification key r2. Multiply the received first random verification key r1 to generate a third random verification key (

) Can be created. Here, the second random signing key

Is a random value satisfying the second random verification key, and the second random verification key

It means the value.

The second electronic device 100-2 may calculate the first electronic signature value e using Equation 1 described above.

The second electronic device 100-2 encodes (or encrypts) the generated first electronic signature value using a homogeneous cryptographic secret key. In detail, the second electronic device 100-2 may homogeneously encrypt the first electronic signature value e calculated using the homologous secret secret key. The second electronic device 100-2 may transmit the encoded first electronic signature value e to the first electronic device 100-1.

When receiving the encoded first electronic signature value e from the second electronic device 100-2, the first electronic device 100-1 receives the received first electronic signature value e and the signature previously generated. The temporary digital signature value s' may be generated using the key x and the first random signature key k1. The first electronic device 100-1 may transmit the generated temporary electronic signature value s ′ to the second electronic device 100-2.

When the temporary electronic signature value s ' is received from the first electronic device 100-1, the second electronic device 100-2 receives the temporary electronic signature value s' using the same type secret key. The second electronic signature value s may be calculated using the decoded temporary digital signature value s' and the second random signature key k2 corresponding to the second random verification key r2. .

The second electronic device 100-2 may generate electronic signatures e and s for the message using the calculated first electronic signature value e and the second electronic signature value s.

6 is a diagram for describing a method of generating an electronic signature in a first electronic device of the present disclosure.

Referring to FIG. 6, a first electronic signature value constituting an electronic signature is calculated using a message (S610). In detail, the first random verification key is received from an external device, the second random verification key is generated, and the third random verification key is generated using the received first random verification key and the generated second random verification key. Can be. The first electronic signature may be calculated using the generated third random verification key and the message. Here, each of the first random verification key and the second random verification key may be an element of a set having a prime order.

The calculated first digital signature value is encoded using the homogeneous cryptographic signature key (S620). In detail, the first digital signature value calculated using the homologous cryptographic signature key may be homogenized. Here, the isomorphic signature key may be calculated from a ring, which is a set in which addition and multiplication are defined between elements, and which is closed for addition and multiplication.

The encoded first digital signature value may be transmitted to the external device, and correspondingly, the temporary digital signature value calculated using the encoded first digital signature value may be received from the external device.

When a temporary digital signature value calculated using the encoded first digital signature value is received, the second digital signature value constituting the digital signature is calculated by decoding the received temporary digital signature value using a homogeneous cryptographic signature key. (S630). Specifically, the received temporary digital signature value is decoded using the homogeneous cryptographic signature key, and the second digital signature value is calculated using the second random signature key corresponding to the decoded temporary digital signature value and the second random verification key. can do.

The electronic signature for the message is generated using the calculated first and second digital signature values.

As described above, the electronic signature method according to the present embodiment performs homogeneous encryption of a message when the electronic signature is performed through cooperation with an external device, thereby preventing the contents of the message from being disclosed to the external device. In addition, the generated electronic signature is the same as the existing electronic signature, and the time required for verification is also the same as the existing electronic signature. The electronic signature method as shown in FIG. 6 may be executed on an electronic device having the configuration of FIG. 2 or 3, or may be executed on an electronic device having other configurations.

Meanwhile, the electronic signature method according to the above-described embodiment may be implemented as a program and provided to the display device. In particular, the program including the electronic signature method may be stored and provided in a non-transitory computer readable medium.

7 is a diagram for describing a control method of a second electronic device of the present disclosure.

에서 임의의 원소 x(서명키)를 추출할 수 있으며, 추출된 원소를 기초로 군 G의 원소(

)인 검증키를 생성할 수 있다. First, a signature key x and a verification key y required for an electronic signature may be generated (S710). Specifically, a set

You can extract any element x (signature key) from, and based on the extracted elements,

You can create a verification key with).

In operation S720, a first random verification key may be generated. In detail, when a request for initiation of a signature protocol is requested from an external device, a first random signature key k1 to be used as a random value may be generated, and a first random verification key r1 corresponding to the first random signature key may be calculated. . The calculated first random verification key may be transmitted to the device requesting protocol initiation.

In operation S730, a temporary electronic signature value is generated. Specifically, upon receiving the encoded first digital signature value e from an external device, the received first digital signature value e , the previously generated signature key x, and the first random signature key k1 are used. To generate a temporary digital signature value s' .

The generated temporary digital signature value s' may be transmitted to an external device (S740).

The electronic signature method and control method as described above can be used not only for execution results of various applications but also for collecting various types of credit or personal information directly input by a user.

Meanwhile, the electronic signature method and the control method according to the various embodiments described above may be implemented in the form of program code for performing each step, and may be stored and distributed in a recording medium. In this case, the apparatus on which the recording medium is mounted can perform the above operations such as encryption or cipher text processing.

Such recording media may be various types of computer readable media such as ROM, RAM, memory chips, memory cards, external hard drives, hard drives, CDs, DVDs, magnetic disks, or magnetic tapes.

While the present disclosure has been described with reference to the accompanying drawings, the scope of the present disclosure is determined by the claims below and should not be construed as limited to the embodiments and / or drawings described above. And it should be clearly understood that improvements, changes and modifications apparent to those skilled in the art of the disclosure described in the claims are included in the scope of the present disclosure.

100: electronic device 200: server device
110: communication device 120: memory
130: process 140: display
150: operation input device

Claims (14)

In the digital signature generation method,
Calculating a first digital signature value constituting the digital signature using the message;
Encoding the calculated first digital signature value using a homogeneous cryptographic signature key;
When a temporary digital signature value calculated using the encoded first digital signature value is received, a second digital signature value constituting the digital signature by decoding the received temporary digital signature value using the homogeneous cryptographic signature key. Calculating; And
Generating an electronic signature for the message using the calculated first and second digital signature values;
Computing the first digital signature value,
Receiving a first random verification key from an external device;
Generating a second random verification key;
Generating a third random verification key using the received first random verification key and the generated second random verification key; And
And calculating the first digital signature value by using the generated third random verification key and the message. delete The method of claim 1,
Each of the first random verification key and the second random verification key,
A method of generating a digital signature that is an element of a set having a prime order. The method of claim 1,
The encoding step,
And isomorphically encrypting the calculated first digital signature value using the homogeneous cryptographic signature key. The method of claim 1,
The isomorphic signature key,
A method for generating an electronic signature, wherein addition and multiplication are defined between elements, and are derived from a ring, a closed set for addition and multiplication. In the digital signature generation method,
Calculating a first digital signature value constituting the digital signature using the message;
Encoding the calculated first digital signature value using a homogeneous cryptographic signature key;
When a temporary digital signature value calculated using the encoded first digital signature value is received, a second digital signature value constituting the digital signature by decoding the received temporary digital signature value using the homogeneous cryptographic signature key. Calculating; And
Generating an electronic signature for the message using the calculated first and second digital signature values;
The electronic signature generation method,
Transmitting the encoded first digital signature value to an external device; And
Receiving a temporary digital signature value calculated using the encoded first digital signature value from the external device;
The temporary electronic signature value is,
And a first random signature key corresponding to a signature key, the encoded first digital signature value, and a first random verification key. The method of claim 6,
Computing the second electronic signature value,
Decoding the received temporary digital signature value using the isomorphic signature key; And
And calculating the second digital signature value by using the decoded temporary digital signature value and a second random signature key corresponding to the second random verification key. In an electronic device,
A communication device communicating with an external device;
Memory for storing messages; And
A processor configured to calculate a first digital signature value constituting the digital signature using the stored message and to encode the calculated first digital signature value using a homogeneous cryptographic signature key;
The processor,
And when the temporary digital signature value calculated using the encoded first digital signature value is received from the external device, decoding the received temporary digital signature value using the homogeneous cryptographic signature key to configure the digital signature. Calculate a digital signature value, and generate an electronic signature for the message using the calculated first and second digital signature values,
The communication device,
Receiving a first random verification key from an external device,
The processor,
Generate a second random verification key, generate a third random verification key using the received first random verification key and the generated second random verification key, and generate the generated third random verification key and the message. And calculating the first electronic signature value by using the electronic device. delete The method of claim 8,
Each of the first random verification key and the second random verification key,
An electronic device that is an element of a set with prime order. The method of claim 8,
The processor,
And homogeneously encrypting the calculated first digital signature value using the homogeneous signature signature key to encode the calculated first digital signature value. The method of claim 8,
The isomorphic signature key,
An electronic device in which addition and multiplication are defined between elements and are derived from a ring, a closed set for addition and multiplication. In an electronic device,
A communication device communicating with an external device;
Memory for storing messages; And
A processor configured to calculate a first digital signature value constituting the digital signature using the stored message and to encode the calculated first digital signature value using a homogeneous cryptographic signature key;
The processor,
And when the temporary digital signature value calculated using the encoded first digital signature value is received from the external device, decoding the received temporary digital signature value using the homogeneous cryptographic signature key to configure the digital signature. Calculate a digital signature value, and generate an electronic signature for the message using the calculated first and second digital signature values,
The communication device,
Transmit the encoded first digital signature value to the external device to an external device, and receive a temporary digital signature value calculated using the encoded first digital signature value from the external device,
The temporary electronic signature value is,
And a first random signature key corresponding to a signature key, the encoded first electronic signature value, and a first random verification key. The method of claim 13,
The processor,
The received temporary digital signature value is decoded using the homogeneous cryptographic signature key, and the second digital signature value is decoded using a second random signature key corresponding to the decoded temporary digital signature value and a second random verification key. Calculating electronic device.

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