KR101865703B1 - Apparatus and method for generating key, apparatus and method for encryption - Google Patents

Abstract

The key generation apparatus according to an exemplary embodiment of the present invention includes a receiver for receiving a key generation request including an ID generated according to a predetermined ID constraint condition from a key requesting terminal, Extracting secret parameter values corresponding to positions in the received ID of each of the symbols included in the received ID from a secret parameter table including secret parameter values by ID in the ID, A secret key generating unit for generating a secret key corresponding to the received ID, and a key information providing unit for providing the secret key to the key requesting terminal.

Description

[0001] APPARATUS AND METHOD FOR GENERATING KEY, APPARATUS AND METHOD FOR ENCRYPTION [0002]

Embodiments of the invention relate to key generation techniques for encryption and encryption.

Recently, due to the development of computer technology and the rapid expansion of communication network, security issues related to computer related resources and transmitted data are becoming a big issue. As an alternative to this problem, password-based systems are being used. In the conventional public key system, the public key of the user is required to be authenticated in advance, and the certificate in question must be discarded even before the expiration of the expiration date. Therefore, Difficulties arise. Therefore, an ID-based cryptosystem based on an individual's identity (ID) has been proposed.

A public key based cryptosystem follows a scheme in which a secret key is first determined and a public key is calculated. On the other hand, the ID-based cryptosystem selects the ID first, calculates the secret key from the ID, and issues the secret key through the secure channel calculated from the ID of the PKG (private key generator).

In this connection, Korean Patent Registration No. 10-1301609, which is a prior art document, discloses a secret-number-based secret-number-calculation method using a discrete logarithm calculation method using an advance calculation table in an ID-based cryptosystem, We propose a method to calculate the key. However, the method proposed in the related patent document requires a lot of time and cost (100 days by Amazon EC2 standard 100 core) to generate the secret key for the user's ID due to the preliminary calculation. Therefore, there is a problem in that it is inefficient in time and cost when a separate key generation is required according to the provided service

Korean Registered Patent No. 10-1301609 (Bulletin of September 29, 2013)

Embodiments of the present invention provide an apparatus and method for generating a key for encryption and an encryption apparatus and method.

The key generation apparatus according to an exemplary embodiment of the present invention includes a receiver for receiving a key generation request including an ID generated according to a predetermined ID constraint condition from a key requesting terminal, Extracting secret parameter values corresponding to positions in the received ID of each of the symbols included in the received ID from a secret parameter table including secret parameter values by ID in the ID, A secret key generating unit for generating a secret key corresponding to the received ID, and a key information providing unit for providing the secret key to the key requesting terminal.

The secret key generation unit may generate the secret key using the sum of the extracted secret parameter values.

The secret key is expressed by the following equation

(Where Sk is the secret key, n is the number of digits of the received identity, S _i is a secret parameter value corresponding to the symbol of the ith position in the received identity, and R is any random number) .

Wherein the position in the ID is a position in each divided block when the ID is divided into a plurality of blocks and the secret key generation unit generates the secret key by using values of the extracted secret parameter values, Can be generated.

The secret key is expressed by the following equation

May be generated by (wherein, Sk is the secret key, m is the number of the divided blocks, B _k is the sum of the extracted secret parameter values, R _k is an arbitrary random number of the k-th block).

The R _k may be any random number having a bit number of k times the maximum number of bits that B _k can have.

According to an embodiment of the present invention, there is provided a key generation method comprising: receiving a key generation request including an ID generated according to a predetermined ID constraint condition from a key requesting terminal; Extracting secret parameter values corresponding to positions in the received ID of each of the symbols included in the received ID from a secret parameter table including a secret parameter value for each position in the ID, Generating a secret key corresponding to the received ID, and providing the secret key to the key requesting terminal.

The generating of the secret key may generate the secret key using the sum of the extracted secret parameter values.

The secret key is expressed by the following equation

(Where Sk is the secret key, n is the number of digits of the received identity, S _i is a secret parameter value corresponding to the symbol of the ith position in the received identity, and R is any random number) .

Wherein the position in the ID is a position in each of the divided blocks when the ID is divided into a plurality of blocks, and the step of generating the secret key further comprises the steps of: You can generate a secret key.

The secret key is expressed by the following equation

May be generated by (wherein, Sk is the secret key, m is the number of the divided blocks, B _k is the sum of the extracted secret parameter values, R _k is an arbitrary random number of the k-th block).

The R _k may be any random number having a bit number of k times the maximum number of bits that B _k can have.

The encryption apparatus according to an exemplary embodiment of the present invention transmits a key generation request including a user ID of the encryption apparatus generated according to a predetermined ID constraint condition to a key issuance server, A secret key corresponding to a user ID of the encryption apparatus; a key information acquisition unit for acquiring a secret key corresponding to a user ID of the encryption apparatus; An ID receiving unit for receiving a user ID of the external terminal generated in accordance with the ID constraint condition from the terminal, extracting public parameter values corresponding to positions in the ID of each symbol included in the user ID of the external terminal from the public parameter table , And the extracted public A public key generation unit for generating a public key corresponding to a user ID of the external terminal using parameter values, and a public key generating unit for encrypting data to be transmitted to the external terminal using the public key, And an encryption unit for performing digital signature on the digital signature.

The public key generation unit may generate a public key corresponding to the user ID by using the product of the extracted public parameters.

The position in the ID is a position in each divided block when the user ID of the external terminal is divided into a plurality of blocks. The public key generation unit uses the values obtained by multiplying the extracted public parameter values by each block And generate a public key corresponding to the user ID.

The encryption device may further include: an ID providing unit for providing a user ID of the encryption device to the external terminal, data encrypted using the public key corresponding to the user ID of the encryption device from the external terminal, And decrypting the encrypted data using a secret key corresponding to the user ID of the encryption apparatus or using the public key corresponding to the user ID of the external terminal, And a decryption unit for performing verification of the digitally signed data.

The encryption method according to an embodiment of the present invention includes the steps of transmitting a key generation request including a user ID of an encryption apparatus generated according to a predetermined ID constraint condition to a key issuance server, Acquiring a public parameter table including a public parameter value for each location in an ID of all symbols that can be generated according to a condition and a secret key corresponding to a user ID of the encryption apparatus; Extracting a public parameter value corresponding to a position in an ID of each symbol included in a user ID of the external terminal from the public parameter table based on the user ID of the external terminal generated according to the ID constraint condition, The extracted public parameters Generating a public key corresponding to a user ID of the external terminal using the public key, encrypting data to be transmitted to the external terminal using the public key, or performing digital signature on the data to be transmitted using the private key .

The generating of the public key may generate a public key corresponding to the user ID using the product of the extracted public parameters.

Wherein the position in the ID is a position in each divided block when the user ID of the external terminal is divided into a plurality of blocks, and the step of generating the public key includes: Values to generate a public key corresponding to the user ID.

The encryption method includes the steps of: providing a user ID of the encryption apparatus to the external terminal; using the encrypted data or the secret key of the external terminal using the public key corresponding to the user ID of the encryption apparatus from the external terminal; And decrypting the encrypted data using the secret key corresponding to the user ID of the encryption apparatus, or using the public key corresponding to the user ID of the external terminal, And performing verification on the data.

According to the embodiments of the present invention, by generating the secret key using the secret parameter corresponding to 1: 1 corresponding to the position of the symbol constituting the identity of the user, precomputation required in the prior art is not required, The processing time and cost required for generation can be remarkably reduced.

1 is a block diagram of an encryption system according to an embodiment of the present invention;
2 is a block diagram of a key generating apparatus according to an embodiment of the present invention.
3 is a block diagram of a key generation apparatus according to a further embodiment of the present invention
4 is an exemplary diagram showing an example of a secret parameter table
5 is an exemplary diagram showing another example of the secret parameter table
6 is an exemplary diagram showing an example of a public parameter table
7 is an exemplary diagram showing another example of the disclosure parameter table
8 is a block diagram of an encryption apparatus according to an embodiment of the present invention.
9 is a flowchart of a key generation method according to an embodiment of the present invention
10 is a flowchart of a key generation method according to a further embodiment of the present invention
11 is a flowchart showing an encryption process according to an embodiment of the present invention.
12 is a flowchart showing a decoding process according to an embodiment of the present invention.
FIG. 13 is a flow chart illustrating a digital signature execution process according to an embodiment of the present invention.
14 is a flow chart illustrating a verification procedure for digitally signed data according to an embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following detailed description is provided to provide a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, this is merely an example and the present invention is not limited thereto.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention or custom of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification. The terms used in the detailed description are intended only to describe embodiments of the invention and should in no way be limiting. Unless specifically stated otherwise, the singular form of a term includes plural forms of meaning. In this description, the expressions " comprising " or " comprising " are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, Should not be construed to preclude the presence or possibility of other features, numbers, steps, operations, elements, portions or combinations thereof.

1 is a configuration diagram of an encryption system according to an embodiment of the present invention.

Referring to FIG. 1, an encryption system 100 according to an exemplary embodiment of the present invention includes a key issuing server 110 and a user terminal 12, 130.

The key issuing server 110 may be a server operated by, for example, a trusted authority or an encryption service provider, and may generate key information for encryption in response to a key generation request of the user terminals 120 and 130. In addition, the key issuing server 110 can provide the generated key information to each of the user terminals 120 and 130 through a secure channel.

In this case, the key information may include a public parameter table for generating a public key using a secret key corresponding to a user ID of each of the user terminals 120 and 130 and a user ID, as described later.

Each of the user terminals 120 and 130 may be a device for performing encryption / decryption or digital signature and verification of data by receiving key information from the key issuing server 110. For example, each of the user terminals 120 and 130 may include an information processing function, a data storage function, and a wired or wireless network such as a smart phone, a PDA, a pavlet, a desktop PC, a laptop PC, a tablet PC, And may be various types of computing devices having a data communication function through the Internet.

Each of the user terminals 120 and 130 may transmit a user ID to the key issuing server 110 to request a key generation. In addition, each of the user terminals 120 and 130 can receive the public parameter table and the secret key corresponding to the user ID from the key issuing server 110. [

At this time, the secret key transmitted from the key issuing server 110 to each of the user terminals 120 and 130 may have a different value according to the user ID transmitted from each of the user terminals 120 and 130. On the other hand, the public parameter table transmitted from the key issuing server 110 to each of the user terminals 120 and 130 may be the same regardless of the user ID transmitted from each of the user terminals 120 and 130, The terminals 120 and 130 may share the same public parameter table.

On the other hand, each of the user terminals 120 and 130 receiving the private key and the public parameter table from the key issuing server 110 performs encryption / decryption using the received secret key and the public parameter table, Signature and verification of the digitally signed data.

For example, the user terminal 120 may receive the user ID of the user terminal 130 and generate a public key corresponding to the received user ID using the public parameter table. The user terminal 120 may encrypt the data using the generated public key and transmit the encrypted data to the user terminal 130.

At this time, the user terminal 130 receiving the encrypted data from the user terminal 120 can decrypt the encrypted data using the secret key received from the key issuing server 110.

Similarly, the user terminal 130 may receive the user ID of the user terminal 120 and generate a public key corresponding to the received user ID using the public parameter table. Also, the user terminal 130 may encrypt the data using the generated public key, and then transmit the encrypted data to the user terminal 120.

At this time, the user terminal 120 receiving the encrypted data from the user terminal 130 can decrypt the encrypted data using the secret key received from the key issuing server 110.

In another example, the user terminal 120 performs a digital signature on the data using the secret key received from the key issuing server 110, and transmits the digitally signed data and the user ID of the user terminal 120 to the user terminal 130 ).

At this time, the user terminal 130 receiving the digitally signed data from the user terminal 120 and the user ID of the user terminal 120 can generate the public key corresponding to the received user ID using the public parameter table . The user terminal 130 may then perform verification of the digitally signed data received using the generated public key.

Similarly, the user terminal 130 performs digital signature on the data using the secret key received from the key issuing server 110, and transmits the digitally signed data and the user ID of the user terminal 130 to the user terminal 120, .

At this time, the user terminal 120 receiving the digitally signed data from the user terminal 130 and the user ID of the user terminal 130 can generate a public key corresponding to the received user ID using the public parameter table . The user terminal 120 may then perform verification of the digitally signed data received using the generated public key.

2 is a configuration diagram of a key generation apparatus according to an embodiment of the present invention.

Referring to FIG. 2, a key generation apparatus 200 according to an exemplary embodiment of the present invention includes a receiving unit 210, a secret key generating unit 220, and a key information providing unit 230.

In one embodiment of the present invention, the key generation apparatus 200 may be implemented, for example, as one configuration of the key issuing server 110 shown in FIG.

The receiving unit 210 receives a key generation request including an ID generated according to a predetermined ID constraint condition from a key requesting terminal (for example, the user terminals 120 and 130 in FIG. 1).

At this time, the ID constraint condition may include one or more rules that an ID must be satisfied at the time of ID creation, and may be preset by the provider of the cryptographic service. Specifically, the ID constraint condition may include, for example, the type of symbol (e.g., uppercase letters, lowercase letters, numbers, special characters, etc.) available for constructing the ID and the maximum number of digits of the ID. However, the ID constraint condition is not necessarily limited to the above-described example. For example, the ID constraint condition may include a minimum number of digits of ID, a combination of symbols of different kinds (for example, a combination of uppercase letters and numbers) Various conditions can be added accordingly.

Symbols may mean any type of letters, numbers, symbols, special characters, etc. that can be input using a computing device.

When a key generation request is received from the key requesting terminal, the secret key generating unit 220 extracts secret parameter values corresponding to the positions in the received IDs of the symbols included in the received ID from the secret parameter table. Also, the secret key generation unit 220 generates a secret key corresponding to the received ID using the extracted secret parameter values.

At this time, the secret parameter table may include secret parameter values for each position in the ID for each of all available symbols according to the ID constraint. The secret parameter table will be described later in detail.

Meanwhile, according to an embodiment of the present invention, the secret key corresponding to the received ID can be generated using the sum of secret parameter values extracted.

Specifically, the secret key may be generated, for example, according to Equation (1) below.

[Equation 1]

Where Sk is the secret key, n is the number of digits of the received identity, S _i is the secret parameter value corresponding to the symbol at the ith position in the received identity, and R is an arbitrary random number.

Meanwhile, according to another embodiment of the present invention, when a key generation request is received from the key requesting terminal, the secret key generating unit 220 divides the received ID into a plurality of blocks, And extracts secret parameter values corresponding to positions in each block of the respective symbols. Also, the secret key generation unit 220 generates a secret key corresponding to the received ID using the extracted secret parameter values.

At this time, the secret key corresponding to the received ID can be generated using the values of the extracted secret parameter values for each block.

Specifically, the secret key may be generated, for example, according to Equation (2) below.

&Quot; (2) "

In this case, Sk is the secret key, m is the number of divided blocks, B _k is the sum of secret parameter values extracted for the kth block, and R _k is an arbitrary random number.

According to an embodiment of the present invention, R _k may be an arbitrary random number having a bit number of k times the maximum number of bits that B _k can have.

Specifically, in the case of generating the secret key according to Equation (2), it is possible that even if the secret parameters included in the secret parameter table all have different values, the sum of secret parameters extracted for different identities may be equal, , The same secret key can be generated for different identities.

On the other hand, when R _k in Equation (2 ₎ is an arbitrary random number having a bit number of k times the maximum number of bits B _k can have, it is possible to prevent the same secret key from being generated for different IDs.

Specifically, if it is assumed that each secret parameter value included in the secret parameter table has a size of 128 bits and that the ID is divided into blocks of four digits, the secret parameter values extracted from the secret parameter table are summed That is, the size of B _k ) becomes maximum 130 bits. Therefore, Rk multiplied by Bk is an arbitrary random number having a bit number of 130 k.

In this case, R _{1, which} is a random number multiplied by B ₁ in Equation (2), is a random number having a size of 130 bits, and R ₂ , which is a random number multiplied by B ₂ , is a random number having a size of 260 bits. Also, since the B _k value becomes a value having a different bit size according to k as R _k is multiplied, even if the sum of secret parameters extracted for different identities is the same, the secret key generated according to Equation (2) .

Meanwhile, when the secret key for the ID received from the key requesting terminal is generated, the key information providing unit 230 provides the generated secret key to the key requesting terminal.

In one embodiment, the receiving unit 210, the secret key generating unit 220, and the key information providing unit 230 shown in FIG. 2 include one or more processors and a computer-readable recording medium coupled to the processor. Or more on a computing device. The computer readable recording medium may be internal or external to the processor, and may be coupled to the processor by any of a variety of well known means. A processor in the computing device may cause each computing device to operate in accordance with the exemplary embodiment described herein. For example, a processor may execute instructions stored on a computer-readable recording medium, and instructions stored on the computer readable recording medium may cause a computing device to perform operations in accordance with the exemplary embodiments described herein For example.

3 is a configuration diagram of a key generating apparatus according to a further embodiment of the present invention.

3, a key generation apparatus 300 according to an exemplary embodiment of the present invention includes a receiver 210, a secret key generator 220, a key information provider 230, a secret parameter generator 240, A secret parameter table generation unit 250, a public parameter generation unit 260, and a public parameter table generation unit 270. [

In the embodiment shown in FIG. 3, the key generation apparatus 300 may be embodied as a configuration of the key issuing server 110 shown in FIG. 1, for example.

The secret parameter generator 240 generates a secret parameter value for each symbol in the ID of each symbol for all symbols available for ID generation according to a predetermined ID constraint. According to an embodiment of the present invention, the secret parameter generator 240 generates secret parameter values corresponding to positions in the ID of each symbol with respect to all symbols available for ID generation according to the ID constraint condition Can be generated.

For example, the secret parameter generation unit 240 generates an arbitrary value according to the position in the ID for each available symbol according to the ID constraint condition, encrypts the generated arbitrary value with the AES algorithm, It is possible to generate a secret parameter corresponding to a specific position in the ID.

In this case, according to an embodiment of the present invention, the secret parameter generator 240 divides the maximum number of digits of IDs that can be generated according to the ID constraint condition into a plurality of blocks, A secret parameter value corresponding to each position in each divided block of each symbol can be generated.

For example, when the maximum number of digits of the ID according to the ID constraint condition is 24 digits, the secret parameter generation unit 240 may divide 24 digits into 4 blocks by 4 digits. In addition, the secret parameter generator 210 may generate secret parameter values corresponding to positions within each of six divided blocks, for each of all symbols that can be generated according to the ID constraint condition.

Meanwhile, according to an embodiment of the present invention, the secret parameter values generated by the secret parameter generation unit 240 may all be different.

Specifically, the secret-parameter generating unit 240 may generate an arbitrary value according to a position in a block of each symbol, using, for example, a mapping function according to Equation (1) below.

&Quot; (3) "

Equation (3) represents a mapping function for the p-th position of the specific symbol (x) in the i-th block among the divided blocks, and r represents an arbitrary random number.

If an arbitrary value is generated according to the position of each symbol in the block according to Equation (3), the secret parameter generator 240 encrypts each generated random value with the AES algorithm, To generate a secret parameter value.

Meanwhile, the secret parameter value generation method by the secret parameter generation unit 240 is not necessarily limited to the above-described example. If the secret parameter value generation unit 240 can generate different values according to the position in the ID of each symbol that can be generated according to the ID constraint condition, It should be noted that any method is available.

Meanwhile, the secret parameter table generation unit 250 generates a secret parameter table including the secret parameter values generated by the secret parameter generation unit 240.

Specifically, the secret parameter table generation unit 250 may generate a secret parameter table by indexing each secret parameter value generated by the secret parameter generation unit 240 to a position in the ID of a corresponding symbol.

As a specific example, FIG. 4 is an exemplary view showing an example of the secret parameter table.

In the example shown in FIG. 4, it is assumed that only uppercase letters are available for user ID generation according to the ID constraint, and the maximum number of digits of the ID is i.

In the illustrated example, P _i represents the position of the symbol in the identity. Specifically, P ₁ represents the first position in the ID, and P ₂ represents the second position in the ID.

In addition, A _i to Z _i represents a secret parameter value corresponding to the i-th position within the ID of each symbol. For example, A ₁ is a secret parameter value for a case where symbol A is located at the first position in the ID, and B ₁ is a secret parameter value for a case where symbol B is located at the first position in the ID.

5 is an exemplary view showing another example of the secret parameter table.

In the example shown in FIG. 5, it is assumed that only uppercase letters are available for user ID generation according to the ID constraint condition, and the maximum number of digits of the ID is divided into k blocks by i digits.

In the illustrated example, P _i represents the position of a symbol in each block (Block 1 to Block k). Specifically, P ₁ in Block 1 represents the first position in Block 1, and P ₂ represents the second position in Block 1. In Block 2, P ₁ represents the first position in Block 2, and P ₂ represents the second position in Block 2.

In addition, A _ki to Z _ki represent secret parameter values corresponding to the i-th position of each symbol in the k-th block. For example, A ₁₁ is a secret parameter value for a case where symbol A is located at the first position in Block 1, and B ₂₁ is a secret parameter value for a case where symbol B is located at the first position in Block 2.

On the other hand, the public parameter generation unit 260 uses the secret parameter value generated by the secret parameter generation unit 240 to calculate a public parameter value for each symbol in the ID of each symbol for all available symbols according to the ID constraint condition .

Specifically, the public parameter generation unit 260 may generate a public parameter value for each position in the ID of each symbol according to Equation (4), for example.

&Quot; (4) "

Here, P _Xi is a public parameter value corresponding to the i-th position in the ID of the specific symbol available according to the ID constraint condition, Xi is a secret parameter value corresponding to the i-th position in the ID of the specific symbol, R is a random number, g is a generator of a finite group Z _N = {0, 1, 2, ..., N-1} of the largest circulating subgroup G, N is an integer satisfying N = pq, 3 (mod 4), and q≡3 (mod 4). Hereinafter, g, R and N are used in the same sense.

As another example, when the secret parameter value generated by the secret parameter generation unit 240 is the secret parameter value for each position in the divided block of each symbol, the public parameter generation unit 260 generates a secret parameter value by dividing each symbol Thereby generating a public parameter value for each position in the block.

&Quot; (5) "

는 아이디 제약 조건에 따라 이용 가능한 특정 심볼의 k번째 블록 내 i 번째 위치에 대응되는 공개 파라미터 값, X_ki는 특정 심볼의 k번째 블록 내 i 번째 위치에 대응되는 비밀 파라미터 값, R_k는 임의의 난수를 나타낸다.At this time,

The public parameter value corresponding to the k-th block in the i-th position of a particular symbol is available in accordance with the identity constraints, X _ki is a secret corresponding to within the i-th position k-th block of the particular symbol parameter values, R _k is an arbitrary Represents a random number.

On the other hand, the public parameter table generating unit 270 generates a public parameter table including the public parameter values generated by the public parameter generating unit 260.

Specifically, the public parameter table generating unit 270 may generate a public parameter table by indexing each public parameter value generated by the public parameter generating unit 260 into a position in the ID of a corresponding symbol.

As a specific example, FIG. 6 is an exemplary view showing an example of a public parameter table.

In the example shown in FIG. 6, it is assumed that only uppercase letters are available for user ID generation according to the ID constraint, and the maximum number of digits of ID is i.

In the illustrated example, P _i represents the position of the symbol in the identity. Specifically, P ₁ represents the first position in the ID, and P ₂ represents the second position in the ID.

Also, g ^{Ai R} to g ^{Zi R} denote the public parameter values corresponding to the i-th position of each symbol. For example, g ^A1R is the disclosure parameter value for the case where the symbol A is located in the first position in the ID, and g ^B1R is the disclosure parameter value for the case where the symbol B is located in the first position in the ID.

7 is an exemplary view showing another example of the disclosure parameter table.

In the example shown in FIG. 7, it is assumed that only uppercase letters are available for user ID generation according to the ID constraint condition, and the maximum number of digits of the ID is divided into k blocks by i digits.

In the illustrated example, P _i represents the position of a symbol in each block (Block 1 to Block k). Specifically, P ₁ in Block 1 represents the first position in Block 1, and P ₂ represents the second position in Block 1. In Block 2, P ₁ represents the first position in Block 2, and P ₂ represents the second position in Block 2.

Also, g ^{Aki Rk} through g ^{Zki Rk} denote the public parameter values corresponding to the i-th position of each symbol in the k-th block. For example, g ^A11.R1 is the disclosure parameter value for the case where the symbol A is located at the first position in the block 1, ^gB21.R2 is the public parameter value for the case where the symbol B is located at the first position in the block 2, to be.

Meanwhile, the receiving unit 210 receives a key generation request including an ID generated according to an ID constraint condition from a key requesting terminal (for example, the user terminals 120 and 130 in FIG. 1).

On the other hand, when a key generation request is received from the key requesting terminal, the secret key generating unit 220 extracts secret parameter values corresponding to positions in the received ID of each symbol included in the ID received from the secret parameter table. Also, the secret key generation unit 220 generates a secret key corresponding to the received ID using the extracted secret parameter values.

At this time, according to an embodiment of the present invention, the secret key corresponding to the received ID can be generated using the sum of secret parameter values extracted.

Specifically, the secret key may be generated, for example, according to Equation (1) described above.

For example, assuming that the secret parameter table generated by the secret parameter table generation unit 250 is as shown in FIG. 4, when the ID received from the key request terminal is 'ABCDEFGH', the secret parameter value Are A ₁ , B ₂ , C ₃ , D ₄ , E ₅ , F ₆ , G ₇ , and H ₈ .

Also, the secret key Sk for the received ID 'ABCDEFGH' is (A ₁ + B ₂ + C ₃ + D ₄ + E ₅ + F ₆ + G ₇ + H ₈ ) R according to Equation 1 .

Meanwhile, according to another embodiment of the present invention, when a key generation request is received from the key requesting terminal, the secret key generating unit 220 divides the received ID into a plurality of blocks, And extracts secret parameter values corresponding to positions in each block of the respective symbols. Also, the secret key generation unit 220 generates a secret key corresponding to the received ID using the extracted secret parameter values.

At this time, the secret key corresponding to the received ID can be generated using the values of the extracted secret parameter values for each block.

Specifically, the secret key may be generated, for example, according to Equation (2) described above.

For example, assuming that the secret parameter table generated by the secret parameter table generation unit 250 is as shown in FIG. 5 and the number of digits of each block is 4 (i = 4), the ID received from the key request terminal is 'ABCDEFGH', secret parameter values extracted from the secret parameter table are A ₁₁ , B ₁₂ , C ₁₃ , D ₁₄ , E ₂₁ , F ₂₂ , G ₂₃ and H ₂₄ .

That is, the secret key generation unit 220 divides the received ID 'ABCDEFGH' into four blocks of 'ABCD' and 'EFGH', and then divides the received ID 'ABCDEFGH' The secret parameter values A ₁₁ , B ₁₂ , C ₁₃ , and D ₁₄ corresponding to the secret parameter values A ₁₁ , B ₁₂ , C ₁₃ , and D ₁₄ are extracted. Also, the secret key generation unit 220 extracts the secret parameter values E ₂₁ , F ₂₂ , G ₂₃ , and H ₂₄ corresponding to the second block 'EFGH' from Block 2 of the secret parameter table.

In this case, the secret for the received ID 'ABCDEFGH' key (Sk) according to Equation _{2 (A 11 + B 12 +} C 13 + D 14) R 1 + (E 21 + F 22 + G 23 + H 24 ) R ₂ .

Meanwhile, when the secret key for the ID received from the key requesting terminal is generated, the key information providing unit 230 provides the generated secret key and the public parameter table to the key requesting terminal.

3, the secret key generating unit 220, the key information providing unit 230, the secret parameter generating unit 240, the secret parameter table generating unit 250, The public parameter generation unit 260 and the public parameter table generation unit 270 may be implemented on one or more computing devices including one or more processors and a computer-readable recording medium coupled to the processors. The computer readable recording medium may be internal or external to the processor, and may be coupled to the processor by any of a variety of well known means. A processor in the computing device may cause each computing device to operate in accordance with the exemplary embodiment described herein. For example, a processor may execute instructions stored on a computer-readable recording medium, and instructions stored on the computer readable recording medium may cause a computing device to perform operations in accordance with the exemplary embodiments described herein For example.

8 is a configuration diagram of an encryption apparatus according to an embodiment of the present invention.

8, an encryption apparatus 800 according to an exemplary embodiment of the present invention includes a key information obtaining unit 810, an ID receiving unit 820, a public key generating unit 830, an encrypting unit 840, (850), a data receiving unit (860), and a decoding unit (870).

In one embodiment of the present invention, the encryption device 800 may be implemented, for example, in a configuration of the user terminal 120, 130 shown in FIG.

The key information obtaining unit 810 transmits a key generation request including the user ID of the encryption apparatus 800 generated according to the ID constraint condition to the key issuing server 110. The key information obtaining unit 810 obtains the public parameter table and the secret key corresponding to the user ID of the encryption apparatus 800 from the key issuing server 110. [

At this time, the public parameter table and the secret key obtained from the key issuing server 110 have already been described in detail with respect to the key generating apparatus 200, and a detailed description thereof will be omitted.

The ID receiving unit 820 receives the user ID of the external terminal generated according to the ID constraint condition from the external terminal sharing the public parameter table obtained from the key issuing server 110. [

For example, in the example shown in FIG. 1, each user device 210, 220 may obtain the same public parameter table from the key issuing server 110. In this case, if the encryption device 800 is implemented as a configuration of the user device 210, the external device may be the user device 130. [

The public key generation unit 830 extracts public parameter values corresponding to positions in the ID of each symbol included in the user ID of the external terminal in the public parameter table obtained from the key issuing server 110. [ Also, the public key generation unit 830 generates a public key corresponding to the user ID of the external terminal using the extracted public parameter values.

In this case, according to an embodiment of the present invention, the public key generation unit 830 can generate a public key corresponding to the user ID of the external terminal using the product of the extracted public parameters.

For example, if the user ID of the external terminal is 'ABCDEFGH' and the public parameter table is as shown in FIG. 6, the public parameter values extracted from the public parameter table are g ^A1R , g ^B2R , g ^C3R , g ^{D4 R} , g ^{E5 R} , g ^{F6 R} , g ^{G7 R} , g ^{H8 R.}

The public key Pk generated from the extracted public parameter values is as follows.

Pk = g? ^{A1? R?} G? ^{B2? R?} G? ^{C3? R?} G ^{D4? R}占 g ^{E5? R}占 g ^{F6? R}占 g ^{G7? R}占 g ^{H8? R}

= g ^{(A1 + B2 + C3 + D4 + E5 + F6 + G7 + H8) R}

7, the public key generation unit 830 divides the user ID of the external terminal into a plurality of blocks, and generates a public key from the public parameter table And extracts the public parameter values corresponding to positions in the block of each symbol included in each of the divided blocks.

For example, in the example shown in FIG. 7, if i is 4, if the user ID of the external terminal is 'ABCDEFGH', the secret parameter values extracted from the public parameter table are g ^{A11 R1} , g ^{B12 R1} , g ^{C13 R1} , g ^{D14 R1} , g ^{E21 R2} , g ^{F22 R2} , g ^{G23 R2} , g ^{H24 R2} .

That is, the public key generation unit 830 divides the user ID 'ABCDEFGH' of the external terminal into four blocks of 'ABCD' and 'EFGH', and then divides the user ID 'ABCDEFGH' The secret parameter values g ^{A11 R1} , g ^{B12 R1} , g ^{C13 R1} and g ^{D14 R1} corresponding to 'ABCD' are extracted. In addition, the public key generation unit 830 generates secret parameter values g ^{E21 揃 R2} , g ^{F22 揃 R2} , g ^{G23 揃 R2} , g ^{H24 揃 R2} corresponding to the second block 'EFGH' from Block 2 of the public parameter table .

In this case, the public key Pk for the user ID 'ABCDEFGH' of the external terminal is as follows.

Pk = g ^{A11 占 R1}占 g ^{B12 占 R1}占 g ^{C13 占 R1}占 g ^{D14 占 R1}占 g ^{E21 占 R2}占 g ^{F22 占 R2}占 g ^{G23 占 R2}占 g ^{H24 占 R}

= g ^{(A11 + B12 + C13 + D14) 占 R1 + E21 + F22 + G23 + H24 占 R2}

The encryption unit 840 encrypts the data to be transmitted to the external terminal using the public key of the user ID of the external terminal generated by the public key generation unit 830.

For example, the encryption unit 840 may select any random number t and calculate the following ciphertexts (C1, C2) for the data M to be transmitted.

C1 = g ^t (mod N)

C2 = Pk ^t (mod N) XOR M

Meanwhile, according to the embodiment, the encryption unit 840 can perform digital signature on the data to be transmitted to the external terminal using the secret key obtained by the key information acquisition unit 810. [

The ID creator 850 provides the user ID of the encryption device 800 generated according to the ID constraint condition to the external terminal.

The data receiving unit 860 receives the digitally signed data using the encrypted data or the secret key of the external terminal using the public key corresponding to the user ID of the encryption apparatus 800 from the external terminal.

Specifically, the external terminal receiving the user ID of the encryption apparatus 800 can generate the public key in the same manner as the above-described method using the public parameter table shared with the encryption apparatus 800, And transmits the encrypted data to the encryption apparatus 800. [

When the encrypted data is received from the external terminal using the public key corresponding to the user ID of the encryption apparatus 800, the decryption unit 870 encrypts the encrypted data using the secret key obtained by the key information acquisition unit 810, Decoded data.

For example, if the received ciphertext is C1 or C2, the decrypting unit 870 can decrypt it using the secret key Sk obtained by the key information obtaining unit 810 as follows.

M = C1 ^Sk (mod N) XOR C2

If the decrypting unit 870 receives the digitally signed data using the secret key of the external terminal, the decrypting unit 870 decrypts the received data using the public key of the user ID of the external terminal generated by the public key generating unit 830 Can be performed.

7, the key information acquisition unit 810, the ID receiving unit 820, the public key generating unit 830, the encrypting unit 840, the ID providing unit 850, the data receiving unit 860 and decryption unit 870 may be implemented on one or more computing devices that include one or more processors and a computer readable recording medium coupled to the processors. The computer readable recording medium may be internal or external to the processor, and may be coupled to the processor by any of a variety of well known means. A processor in the computing device may cause each computing device to operate in accordance with the exemplary embodiment described herein. For example, a processor may execute instructions stored on a computer-readable recording medium, and instructions stored on the computer readable recording medium may cause a computing device to perform operations in accordance with the exemplary embodiments described herein For example.

9 is a flowchart of a key generation method according to an embodiment of the present invention.

The method shown in Fig. 9 can be performed, for example, by the key generation apparatus 200 shown in Fig.

Referring to FIG. 9, the key generation apparatus 200 receives a key generation request including an ID generated according to an ID constraint condition from a key request terminal (Step 910).

Then, the key generation apparatus 200 extracts secret parameter values corresponding to the positions in the received IDs of the respective symbols included in the received ID from the secret parameter table (920).

Then, the key generation apparatus 200 generates a secret key corresponding to the received ID using the extracted secret parameter values (930).

Then, the key generation apparatus 200 provides the generated secret key to the key request terminal (940).

10 is a flowchart of a key generation method according to a further embodiment of the present invention.

The method shown in Fig. 10 can be performed, for example, by the key generation apparatus 300 shown in Fig.

Referring to FIG. 10, the key generation apparatus 300 first generates a secret parameter value for each position in the ID of each symbol, which is available according to a predetermined ID constraint (1010).

Thereafter, the key generation apparatus 300 generates a secret parameter table indexed at a position in the ID of the symbol corresponding to the generated secret parameter value (1020).

Thereafter, the key generation apparatus 300 generates a public parameter value for each position in the ID of each symbol for all available symbols according to the ID constraint condition, using the generated secret parameter value (1030).

Thereafter, the key generation apparatus 300 generates a public parameter table indexed at a position within the ID of the symbol corresponding to the generated public parameter value (1040).

Then, the key generation apparatus 300 receives a key generation request including the ID generated according to the ID constraint condition from the key request terminal (operation 1050).

Then, the key generation apparatus 300 extracts secret parameter values corresponding to the positions in the received IDs of the respective symbols included in the received ID from the secret parameter table (1060).

Thereafter, the key generation apparatus 300 generates a secret key corresponding to the received ID using the extracted secret parameter values (1070).

Thereafter, the key generation apparatus 300 provides the generated secret key and the public parameter table to the key request terminal (1080).

11 is a flowchart illustrating an encryption process according to an embodiment of the present invention.

The method shown in Fig. 11 can be performed, for example, by the encrypting apparatus 800 shown in Fig.

11, the encryption apparatus 800 transmits a key generation request including the user ID of the encryption apparatus 800 generated according to the predetermined ID constraint condition to the key issuing server 110 (1110).

Thereafter, the encryption apparatus 800 receives from the key issuing server 110 a public parameter table including a public parameter value for each position in the ID of all symbols that can be generated according to the ID constraint condition, and a public parameter table including a user ID of the encryption apparatus 800 A corresponding secret key is obtained (1120).

Thereafter, the encryption apparatus 800 receives the user ID of the external terminal generated according to the ID constraint condition from the external terminal sharing the public parameter table (1130).

Thereafter, the encryption apparatus 800 extracts public parameter values corresponding to positions in the ID of each symbol included in the user ID of the external terminal from the public parameter table (1140).

Thereafter, the encryption apparatus 800 generates a public key corresponding to the user ID of the external terminal using the extracted public parameter values (1150).

Thereafter, the encryption apparatus 800 encrypts the data to be transmitted to the external terminal using the generated public key (1160).

12 is a flowchart illustrating a decoding process according to an embodiment of the present invention.

The method shown in Fig. 12 can be performed, for example, by the encrypting apparatus 800 shown in Fig.

Referring to FIG. 12, the encryption apparatus 800 transmits a key generation request including the user ID of the encryption apparatus 800 generated according to a predetermined ID constraint condition to the key issuing server 110 (1210).

Thereafter, the encryption apparatus 800 acquires a public parameter table including public parameter values per location in the ID for all symbols that can be generated according to the ID constraint condition, and a secret key corresponding to the user ID of the encryption apparatus 800 (1220).

Thereafter, the encryption apparatus 800 provides the user ID of the encryption apparatus 800 to the external terminal sharing the public parameter table (1230).

Thereafter, the encryption apparatus 800 receives the encrypted data from the external terminal using the public key corresponding to the user ID of the encryption apparatus 800 (1240).

Thereafter, the encryption apparatus 800 decrypts the received encrypted data using the secret key obtained in operation 1220 (1250).

13 is a flowchart illustrating an electronic signature process according to an exemplary embodiment of the present invention.

The method shown in Fig. 13 can be performed, for example, by the encrypting apparatus 800 shown in Fig.

Referring to FIG. 13, the encryption apparatus 800 transmits a key generation request including the user ID of the encryption apparatus 800 generated according to a predetermined ID constraint condition to the key issuing server 110 (1310).

Thereafter, the encryption apparatus 800 acquires a public parameter table including public parameter values per location in the ID for all symbols that can be generated according to the ID constraint condition, and a secret key corresponding to the user ID of the encryption apparatus 800 (1320).

Then, the encryption apparatus 800 performs digital signature on the data to be transmitted to the external device sharing the public parameter table using the obtained secret key (1330).

FIG. 14 is a flowchart illustrating a verification process of digitally signed data according to an exemplary embodiment of the present invention.

The method shown in Fig. 14 can be performed, for example, by the encrypting apparatus 800 shown in Fig.

Referring to FIG. 14, the encryption apparatus 800 transmits a key generation request including the user ID of the encryption apparatus 800 generated according to a predetermined ID constraint condition to the key issuing server 110 (1410).

Thereafter, the encryption apparatus 800 acquires a public parameter table including public parameter values per location in the ID for all symbols that can be generated according to the ID constraint condition, and a secret key corresponding to the user ID of the encryption apparatus 800 (1420).

Thereafter, the encryption apparatus 800 receives the user ID of the external terminal generated according to the ID constraint condition from the external terminal sharing the public parameter table (1430).

Thereafter, the encryption apparatus 800 extracts public parameter values corresponding to positions in the ID of each symbol included in the user ID of the external terminal from the public parameter table (1440).

Thereafter, the encryption apparatus 800 generates a public key corresponding to the user ID of the external terminal using the extracted public parameter values (1450).

Thereafter, the encryption apparatus 800 receives the digitally signed data using the secret key of the external terminal from the external terminal (1460).

Thereafter, the encryption apparatus 800 performs verification of the received digitally signed data using the public key corresponding to the user ID of the external terminal (1470).

In the flowcharts shown in Figs. 9 to 14, the method is described by dividing into a plurality of steps. However, at least some of the steps may be performed in reverse order, or may be performed together with other steps, omitted, Or one or more steps not shown may be added.

On the other hand, an embodiment of the present invention may include a computer-readable recording medium including a program for performing the methods described herein on a computer. The computer-readable recording medium may include a program command, a local data file, a local data structure, or the like, alone or in combination. The media may be those specially designed and constructed for the present invention, or may be those that are commonly used in the field of computer software. Examples of computer readable media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floppy disks, and magnetic media such as ROMs, And hardware devices specifically configured to store and execute program instructions. Examples of program instructions may include machine language code such as those generated by a compiler, as well as high-level language code that may be executed by a computer using an interpreter or the like.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, . Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by equivalents to the appended claims, as well as the appended claims.

100: Encryption system
110: key issuing server
120, 130: user terminal
200, 300: key generating device
210:
220: secret key generation unit
230: key information providing service
240: secret parameter generation unit
250: secret parameter table generation unit
260: public parameter generating unit
270: public parameter table generation unit
800: Encryption device
810: Key information acquisition unit
820:
830: Public key generation unit
840:
850: Idemija
860: Data receiving section
870:

Claims (20)

A receiving unit receiving a key generation request including an ID generated according to a predetermined ID constraint condition from a key requesting terminal;
A secret parameter value corresponding to a position in the received ID of each symbol included in the received ID from a secret parameter table including a secret parameter value for each position in the ID for each of all available symbols according to the ID constraint value, A secret key generation unit for generating a secret key corresponding to the received ID using the extracted secret parameter values; And
And a key information providing unit for providing the secret key to the key requesting terminal.
The method according to claim 1,
Wherein the secret key generation unit generates the secret key using the sum of the extracted secret parameter values.
The method according to claim 1,
The secret key is expressed by the following equation

(At this time, Sk is the secret key, n is the number of digits of the received ID, S _i is a secret value parameter corresponding to a symbol in the i-th position in the received ID, R is an arbitrary random number)
Is generated by the key generation unit.
The method according to claim 1,
The position in the ID is a position in each divided block when the ID is divided into a plurality of blocks,
Wherein the secret key generation unit generates the secret key using values of the extracted secret parameter values for each block.
The method of claim 4,
The secret key is expressed by the following equation

(In this case, the secret key Sk, m is the number of the divided blocks, B is the sum _k, R _k of the extracted secret parameter values for the k-th block are arbitrary random numbers)
Is generated by the key generation unit.
The method of claim 5,
Wherein R _k is an arbitrary random number having a bit number of k times the maximum number of bits that B _k can have.
Receiving a key generation request including an ID generated according to a predetermined ID constraint condition from a key requesting terminal;
A secret parameter value corresponding to a position in the received ID of each symbol included in the received ID from a secret parameter table including a secret parameter value for each position in the ID for each of all available symbols according to the ID constraint value, ;
Generating a secret key corresponding to the received ID using the extracted secret parameter values; And
And providing the secret key to the key requesting terminal.
The method of claim 7,
Wherein the generating of the secret key comprises generating the secret key using the sum of the extracted secret parameter values.
The method of claim 7,
The secret key is expressed by the following equation

(At this time, Sk is the secret key, n is the number of digits of the received ID, S _i is a secret value parameter corresponding to a symbol in the i-th position in the received ID, R is an arbitrary random number)
/ RTI >
The method of claim 7,
The position in the ID is a position in each divided block when the ID is divided into a plurality of blocks,
Wherein the generating the secret key comprises generating the secret key using values of the extracted secret parameter values for each block.
The method of claim 10,
The secret key is expressed by the following equation

(In this case, the secret key Sk, m is the number of the divided blocks, B is the sum _k, R _k of the extracted secret parameter values for the k-th block are arbitrary random numbers)
/ RTI >
The method of claim 11,
Wherein R _k is an arbitrary random number having a bit number of k times the maximum number of bits that B _k can have.
The key issuing server transmits a key generation request including the user ID of the encryption apparatus generated according to the predetermined ID constraint condition to the key issuance server, A key information acquiring unit for acquiring a public parameter table including a star disclosure parameter value and a secret key corresponding to a user ID of the encryption apparatus;
An ID receiving unit for receiving a user ID of the external terminal generated according to the ID constraint condition from an external terminal sharing the public parameter table;
Extracting from the public parameter table public parameter values corresponding to positions in the ID of each symbol included in the user ID of the external terminal and extracting public key values corresponding to the user ID of the external terminal using the extracted public parameter values, A public key generation unit for generating a public key; And
And an encryption unit encrypting data to be transmitted to the external terminal using the public key or performing digital signature on the data to be transmitted using the secret key.
14. The method of claim 13,
Wherein the public key generation unit generates a public key corresponding to the user ID by using the product of the extracted public parameters.
14. The method of claim 13,
The position in the ID is a position in each divided block when the user ID of the external terminal is divided into a plurality of blocks,
Wherein the public key generation unit generates a public key corresponding to the user ID using values obtained by multiplying the extracted public parameter values by the respective blocks.
14. The method of claim 13,
An ID providing unit for providing a user ID of the encryption apparatus to the external terminal;
A data receiving unit for receiving the digitally signed data using the public key corresponding to the user ID of the encryption device from the external terminal or the secret key of the external terminal; And
A decryption unit decrypting the encrypted data using a secret key corresponding to a user ID of the encryption apparatus or performing verification of the digitally signed data using a public key corresponding to a user ID of the external terminal Encryption device to include.
Transmitting a key generation request including a user ID of the encryption apparatus generated according to a predetermined ID constraint condition to a key issuing server;
Acquiring a secret parameter corresponding to a user ID of the encryption device and a public parameter table including a public parameter value for each location in an ID of all symbols that can be generated according to the predetermined ID constraint condition from the key issuing server;
Receiving a user ID of the external terminal generated according to the ID constraint condition from an external terminal sharing the public parameter table;
Extracting public parameter values corresponding to positions in an ID of each symbol included in a user ID of the external terminal from the public parameter table;
Generating a public key corresponding to a user ID of the external terminal using the extracted public parameter values; And
Encrypting data to be transmitted to the external terminal using the public key, or performing digital signature on the data to be transmitted using the secret key.
18. The method of claim 17,
Generating the public key, and generating a public key corresponding to the user ID using a product of the extracted public parameters.
18. The method of claim 17,
The position in the ID is a position in each divided block when the user ID of the external terminal is divided into a plurality of blocks,
Wherein the step of generating the public key comprises generating a public key corresponding to the user ID by using the values obtained by multiplying the extracted public parameter values by the respective blocks.
18. The method of claim 17,
Providing a user ID of the encryption device to the external terminal;
Receiving the digitally signed data using the encrypted data or the secret key of the external terminal using the public key corresponding to the user ID of the encryption device from the external terminal; And
Decrypting the encrypted data using a secret key corresponding to a user ID of the encryption apparatus or performing verification of the digitally signed data using a public key corresponding to a user ID of the external terminal Encryption method to include.

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