KR20210067125A - System and method for trading power based on blockchain - Google Patents

Abstract

A blockchain-based power trading system and a method thereof are disclosed. The blockchain-based power transaction system according to one aspect of the present invention includes: a user device which receives power transaction information; a power transaction server which receives the power transaction information from the user device, encodes the power transaction information, and encrypts the encoded information; and a blockchain which inputs a ciphertext pair into a seller list or a buyer list, determines whether the transaction is successful using seller ciphertext pairs and buyer ciphertext pairs in the seller list and the buyer list, and transmits success or failure information of transaction to the power trading server, when receiving the ciphertext pair from the power transaction server.

Description

SYSTEM AND METHOD FOR TRADING POWER BASED ON BLOCKCHAIN

The present invention relates to a block chain-based power transaction system and method, and more particularly, a block that can contribute to the proof of the integrity of the result without a third party other than the transaction party knowing the transaction details in a block chain technology-based power transaction environment It relates to a chain-based power trading system and method.

The Smart Grid System is a two-way system that connects power companies and consumers. After collecting data from various devices installed on the consumer side through the intermediate data concentrator (DCU), the collected data It is a two-way infrastructure that transmits data to the corporate server and vice versa, from the server to the consumer. Such smart grid technology plays a significant role in increasing the efficiency of power grid operation by delivering various information and intentions between various distributed resources and consumers. However, since this smart grid technology focuses on operating the physical power grid, real-time performance of settlement and charging for electricity transactions is lacking. Also, since it is a financial transaction for in-kind, there is still a problem that a separate financial system must be established. have.

Blockchain technology is a technology that can verify data without a trusted third party. One block contains information about the transaction (data) to be used and the previous block, and everyone verifies that the block is valid by verifying that the block is valid in a fixed way. A representative example for verification is a method of finding a hash value suitable for a specific difficulty called Proof-of-Work (PoW). To find this hash value, computing power must be used, and it is determined that a user who has used a lot of computing power has verified a valid block, and the block is connected to the block chain and released.

By using this method, the blockchain enables monetary transactions without a specific third party such as a bank or administrator, and Bitcoin is a representative example of this. Bitcoin enables not only simple monetary transactions, but also transactions that can make simple contracts by using the fact that data can be placed in blocks. The Ethereum blockchain, which appeared later, eliminated the disadvantage of Bitcoin, that it could only use simple contracts, and made it possible to implement various programs by enabling complete programming, so that it could play a role as a platform as well as a cryptocurrency. . Due to these advantages, it is also possible to easily implement and use more complex contracts such as reading and sharing medical information and sharing personal statements rather than simple contract transactions. Therefore, we are currently working on projects to enable P2P transactions without the intervention of a third party by grafting this technology in various fields.

However, when data is uploaded to a block on the blockchain, the problem arises that the data content is disclosed to everyone using the blockchain, not just the parties to the transaction. In other words, the blockchain effectively solves the problem of integrity, but it also raises the problem of data confidentiality.

Accordingly, there is a demand for technology development that can prove the integrity of the transaction result without a third party other than the transaction party knowing the transaction details.

As a prior art related to the present invention, there is registered Patent Publication No. 10-1848896 (April 13, 2018 announcement, title of invention: prepaid power sales and power use method using block chain).

The present invention has been devised to improve the above problems, and an object according to an aspect of the present invention is to contribute to the verification of the integrity of the result without a third party other than the transaction party knowing the transaction details in a power transaction environment based on block chain technology. It is to provide a blockchain-based power trading system and method that enables

The problem to be solved by the present invention is not limited to the problem(s) mentioned above, and another problem(s) not mentioned will be clearly understood by those skilled in the art from the following description.

A block chain-based power transaction system according to an aspect of the present invention includes a user device that receives power transaction information, receives power transaction information from the user device, encodes the power transaction information, and encrypts the encoded information. Upon receiving the cipher text pair from the power transaction server and the power transaction server, the cipher text pair is input to the seller list or the buyer list, and whether the transaction is successful using the seller cipher text pairs and the buyer cipher text pairs in the seller list and the buyer list and a block chain for transmitting information on whether the transaction is successful or not to the power transaction server.

In the present invention, the power transaction server includes an encoding unit for generating a first vector and a second vector by encoding the desired transaction amount of the power transaction information, a secret key for the first vector, and the second vector. It may include an encryption unit that generates a ciphertext for the ciphertext and transmits a ciphertext pair including the generated secret key and the ciphertext to the block chain.

In the present invention, the encoding unit may generate a first vector and a second vector by comparing the desired transaction amount with a preset transaction amount range per unit power, and encoding the desired transaction amount based on the comparison result.

In the present invention, the encryption unit generates a secret key for the first vector using a key generation algorithm, generates a cipher text for the second vector using an encryption algorithm, and includes the secret key and the cipher text. A ciphertext pair can be transmitted to the blockchain.

In the present invention, when the block chain receives a pair of encrypted texts from the power transaction server, a record processing unit that checks the requestor of the encrypted text pair and records it in a seller list or a buyer list, and function decryption for the seller encrypted text pairs in the seller list A comparison unit to find a seller ciphertext pair for the minimum value by applying an operation, and a comparison unit to find a buyer ciphertext pair for the maximum value by applying a function decryption operation to the buyer ciphertext pairs in the buyer list, the seller ciphertext pair for the minimum value and the maximum value It may include a transaction processing unit for performing a function decryption operation on the purchaser ciphertext pair, determining whether the transaction is successful, and transmitting information on whether the transaction is successful or not to the power transaction server.

In the present invention, the comparison unit finds the seller cipher text pair for the minimum value among the seller list by comparing the magnitude between the desired sales amounts encoded in the seller cipher text pair by applying a function decryption operation to the seller cipher text pairs of the seller list, By applying a functional decryption operation to the buyer ciphertext pairs of the buyer list and comparing the magnitude between the desired purchase amounts encoded in the buyer ciphertext pair, it is possible to find the buyer ciphertext pair for the maximum value in the buyer list.

In the present invention, the transaction processing unit calculates an inner product by function-decrypting the seller cipher text pair for the minimum value and the buyer cipher text pair for the maximum value, and determines whether the transaction between the seller and the buyer succeeds based on the calculated inner product. have.

In the present invention, the transaction processing unit, the first vector encoded for the minimum value in the seller list by applying a function decryption operation to the secret key of the seller cipher text pair for the minimum value and the cipher text of the buyer cipher text pair for the maximum value, and the Calculate the dot product result of the second vector encoded for the maximum value in the buyer list, and if the calculated dot product is '1', it is determined as a transaction success between the seller and the buyer, and the seller and the buyer whose dot product is '0' It can be determined by the failure of the transaction between them.

In the present invention, when it is determined that the transaction between the seller and the buyer is successful, the transaction processing unit may transmit the seller's address and power transaction information, and the buyer's address and electricity transaction information to the electricity transaction server.

A block chain-based power transaction method according to another aspect of the present invention includes: when a power transaction server receives power transaction information from a user device, encoding the power transaction information and encrypting the encoded information; Upon receiving the ciphertext pair from the power transaction server, the ciphertext pair is input to the seller list or the buyer list, and the transaction success is determined using the seller ciphertext pairs and the buyer ciphertext pairs in the seller list and the buyer list, and the transaction is successful and transmitting whether or not information to the power transaction server.

In the present invention, the encoding of the power transaction information and the encoding of the encoded information may include: generating, by the power transaction server, a first vector and a second vector by encoding the desired transaction amount of the power transaction information; The power transaction server may include generating a secret key for the first vector, generating a cipher text for the second vector, and transmitting a cipher text pair including the generated secret key and cipher text to the block chain. have.

In the present invention, in the step of generating the first vector and the second vector, the power transaction server compares the desired transaction amount with a preset transaction amount range per unit power, and based on the comparison result, the desired transaction amount may be encoded to generate a first vector and a second vector.

In the present invention, in the step of transmitting the cipher text pair including the generated secret key and cipher text to the block chain, the power transaction server generates a secret key for the first vector using a key generation algorithm, and performs an encryption algorithm. After generating the ciphertext for the second vector using the ciphertext, the ciphertext pair including the secret key and the ciphertext may be transmitted to the block chain.

In the present invention, the step of transmitting the transaction success information to the power transaction server includes, when the block chain receives the encrypted text pair from the power transaction server, confirms the requestor of the encrypted text pair and records it in the seller list or the buyer list The block chain applies a function decryption operation to the seller ciphertext pairs in the seller list to find the seller ciphertext pair for the minimum value, and applies the function decryption operation to the buyer ciphertext pairs in the buyer list to apply the function decryption operation to the buyer for the maximum value Finding a ciphertext pair, the block chain performs a function decryption operation on the seller ciphertext pair for the minimum value and the buyer ciphertext pair for the maximum value, determines whether the transaction is successful, and transmits the transaction success information to the power transaction server may include steps.

In the present invention, in the step of finding the buyer cipher text pair for the maximum value, the block chain applies a function decryption operation to the seller cipher text pairs in the seller list by comparing the magnitude between the desired sales amounts encoded in the seller cipher text pair. Find the seller cipher text pair for the minimum value in the seller list, apply a function decryption operation to the buyer cipher text pairs in the buyer list, and compare the magnitude between the desired purchase amounts encoded in the buyer cipher text pair to the maximum value in the buyer list Buyer ciphertext pairs can be found.

In the present invention, in the step of transmitting the transaction success information to the power transaction server, the block chain performs function-decryption of the seller cipher text pair for the minimum value and the buyer cipher text pair for the maximum value to calculate the inner product, and the calculated Based on the dot product, it is possible to determine whether a transaction between the seller and the buyer is successful.

In the present invention, in the step of transmitting the transaction success information to the power transaction server, the block chain applies a function decryption operation to the secret key of the seller cipher text pair for the minimum value and the cipher text of the buyer cipher text pair for the maximum value By doing so, a result of the dot product of the first vector encoded for the minimum value in the seller list and the second vector encoded for the maximum value in the buyer list is calculated, and when the calculated dot product is '1', the transaction between the seller and the buyer is successful , and it may be determined as a transaction failure between the seller and the buyer whose inner product is '0'.

In the present invention, when it is determined that the transaction between the seller and the buyer is successful, the seller's address and electricity transaction information, and the buyer's address and electricity transaction information may be transmitted to the electricity transaction server.

A blockchain-based power transaction system and method according to an embodiment of the present invention encrypts and protects transaction data using a block-chain-based function encryption technique, and at the same time, a third party other than the transaction party does not know the transaction details. It can contribute to the proof of the integrity of the results. In other words, since size comparison is possible in an encrypted state, even if a third party cannot confirm the transaction details, the result of the size comparison can be known, thereby solving the problem of confidentiality of the block chain.

On the other hand, the effects of the present invention are not limited to the above-mentioned effects, and various effects may be included within the range apparent to those skilled in the art from the contents to be described below.

1 is a diagram schematically showing a blockchain-based power trading system according to an embodiment of the present invention.
2 is a block diagram schematically illustrating a power transaction server according to an embodiment of the present invention.
3 is a block diagram for explaining a block chain for executing a smart contract according to an embodiment of the present invention.
4 is a diagram for explaining a blockchain-based power transaction method according to an embodiment of the present invention.

Hereinafter, a blockchain-based power transaction system and method according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of the user or operator. Therefore, definitions of these terms should be made based on the content throughout this specification.

Further, the implementations described herein may be implemented as, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the discussed features may also be implemented in other forms (eg, in an apparatus or a program). The apparatus may be implemented in suitable hardware, software and firmware, and the like. A method may be implemented in an apparatus such as, for example, a processor, which generally refers to a computer, a microprocessor, a processing device, including an integrated circuit or programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants ("PDAs") and other devices that facilitate communication of information between end-users.

1 is a diagram schematically showing a blockchain-based power trading system according to an embodiment of the present invention.

Referring to FIG. 1 , a block chain-based power transaction system according to an embodiment of the present invention includes a user device 100 , a power transaction server 300 , and a block chain 400 .

The user device 100 may be a buyer who purchases electricity or a seller who sells electricity. The user may input a transaction method of whether to purchase or sell electricity, an amount of electricity to be traded, and a desired transaction amount. In this case, the range of the transaction amount may be limited.

The user device 100 transmits power transaction information including a transaction method, a transaction amount, and a desired transaction amount to the power transaction server 300 through a communication network.

Although only one user device 100 is illustrated in FIG. 1 for convenience of understanding, a plurality of user devices 100 may be configured.

When the power transaction server 300 receives power transaction information from the user device 100 , the power transaction information is encoded and the encoded information is encrypted. That is, the power transaction server 300 generates the first vector and the second vector by encoding the desired transaction amount of the power transaction information. Then, the power transaction server 300 generates a secret key for the first vector, generates a cipher text for the second vector, and transmits a cipher text pair including the generated secret key and cipher text to the block chain 400 . do.

A detailed description of the power transaction server 300 will be referred to FIG. 2 .

Meanwhile, in FIG. 1 , a device for managing power trade is referred to as a power trade server 300 , but it may be a platform, a smartphone, a smart meter, a server, or the like. In addition, in addition to going through a simple platform, it is also possible to connect the user and the blockchain 400 through multiple platforms.

When the block chain 400 receives the ciphertext pair from the power transaction server 300, it inputs the ciphertext pair to the seller list or the buyer list, identifies the ciphertext pair of the seller who presented the minimum value among the seller list, and the maximum value in the buyer list Identifies the ciphertext pair of the buyer who presented , and determines the success of the transaction by using the ciphertext pair of the seller who presented the minimum value among the sellers list and the ciphertext pair of the buyer who presented the maximum value among the buyers list. It is transmitted to the transaction server 300 .

The block chain 400 may perform an optimal matching on the encrypted information in the power transaction server 300 to enable power trading. In this case, the block chain 400 may use functional encryption to match the transaction through comparison of the encrypted transaction information.

Function cryptography is when plaintext a and plaintext b are encrypted to generate ciphertext vector A and ciphertext vector B. When input to a specific function, the specific operation value for a and b is generated even if you do not know the key used for encryption or plaintext a and b. It is a cryptographic technique that allows That is, the function cipher refers to a technique in which a function f(a,b) is calculated from the ciphertexts of a and b, but the values of a and b themselves are unknown. In the present invention, in one embodiment, the dot product of two vectors a and b A dot product function cipher that computes , that is, f(a,b) = <a,b> is used, but a function cipher other than the inner product function can also be used. In addition, although P2P power transaction is considered as an embodiment of the present invention, the present invention can be applied to any transaction method based on data size comparison.

)를 생성하는 것을 의미할 수 있다. 암호화는 y벡터에 대해 msk로 암호문(ciphertext,

)를 생성하는 것을 의미할 수 있다. 함수 복호화는

라고 표기하며, 특정 함수에 비밀키(

)와 암호문(

)를 제공하면 두 벡터 x와 y의 내적값을 돌려주는 것을 의미할 수 있다. Dot product cryptography can consist of key parameter setting, key generation, encryption, and function decryption. Key parameter setting may mean generating public parameter pp and master secret key msk that satisfy given safety requirements. Key generation is a secret key (secret key, msk) for the x vector.

) can mean creating Encryption is ciphertext (ciphertext, msk for the y vector)

) can mean creating function decryption

, and the secret key (

) and ciphertext (

) can mean returning the dot product of two vectors x and y.

Examples of the block chain 400 include Ethereum, Bitcoin, Quantum, and the like, and in one embodiment of the present invention, Ethereum will be described as an example.

As an embodiment of the present invention, encryption for power transaction can be implemented using a smart contract provided in the Ethereum block chain 400 . When the seller and the buyer propose the desired power transaction amount and the desired transaction amount, respectively, the encrypted information can be optimally matched on the block chain 400 to be traded.

2 is a block diagram schematically illustrating a power transaction server according to an embodiment of the present invention.

Referring to FIG. 2 , the power transaction server 300 according to an embodiment of the present invention includes an interface unit 310 , an encoding unit 320 , an encryption unit 330 , and a control unit 340 .

The interface unit 310 receives power transaction information including a transaction method, a transaction amount, and a desired transaction amount from the user device 100 through a communication network.

The encoding unit 320 encodes the power transaction information to generate a first vector and a second vector. In this case, the encoding unit 320 may encode the desired transaction amount of the power transaction information. In addition, the encoding unit 320 may encode the power transaction information received from the interface unit 310 so that the size can be compared as an inner product result value.

That is, the encoding unit 320 may check the range P of the transaction amount value per unit power that can be encoded. Here, the range of the transaction amount value per unit power may be a preset range. Then, the encoding unit 320 compares the desired transaction amount with the transaction amount range per unit power, and generates a first vector based on the comparison result. For example, the encoding unit 320 may generate a first vector having a form of 0 for an index smaller than the desired transaction amount, and 1 for an index other than the desired transaction amount. Also, the encoding unit 320 may generate a second vector by one-hot encoding the desired transaction amount.

)를 생성할 수 있다. 또한, 인코딩부(320)는 거래 희망 금액을 one-hot 인코딩하여 제2 벡터(Ub,

)를 생성할 수 있다. For example, if the range (P) of the value of the transaction amount per unit power is P={1, ..., 10}, and '5' is put as the desired transaction amount, the encoding unit 320 is an index smaller than 5 is 0, and other indices are 1 in the form of a first vector (Ua,

) can be created. In addition, the encoding unit 320 one-hot encodes the desired transaction amount to a second vector (Ub,

) can be created.

The encryption unit 330 generates a secret key for the first vector, generates a cipher text for the second vector, and transmits a cipher text pair including the generated secret key and the cipher text to the block chain 400 . That is, the encryption unit 330 generates a secret key for the first vector using a key generation algorithm, generates a cipher text for the second vector using the encryption algorithm, and then a pair of cipher texts including the secret key and the cipher text. is transmitted to the block chain 400 . Here, the key generation algorithm and the encryption algorithm may use a conventional algorithm.

)에 대한 비밀키(secret key,

)를 생성하고, 암호화 알고리즘을 이용하여 제2 벡터(

)에 대한 암호문(

)를 생성한 후 암호문 쌍

을 블록체인(400)에 전달할 수 있다. For example, the encryption unit 330 uses a key generation algorithm to generate the first vector (

) for the secret key,

) and using an encryption algorithm to create a second vector (

) for the ciphertext (

) after generating the ciphertext pair

can be transmitted to the blockchain 400 .

The encryption unit 330 may transmit a transaction method, user identification information, etc. together with the cipher text pair to the block chain 400 .

Meanwhile, the encoding unit 320 and the encryption unit 330 may be implemented by a processor or the like required to execute a program on a computing device, respectively. As such, the encoding unit 320 and the encryption unit 330 may be implemented by physically independent components, or may be implemented in a functionally separate form within one processor.

The control unit 340 is a component that controls the operation of various components of the power transaction server 300 including the interface unit 310 , the encoding unit 320 , and the encryption unit 330 , and includes at least one computing device. In this case, the arithmetic unit may be a general-purpose central processing unit (CPU), a programmable device device (CPLD, FPGA) that is suitably implemented for a specific purpose, an application-specific processing unit (ASIC), or a microcontroller chip.

3 is a block diagram for explaining a block chain for executing a smart contract according to an embodiment of the present invention.

Referring to FIG. 3 , a block chain 400 executing a smart contract according to an embodiment of the present invention includes a record processing unit 410 , a comparison unit 420 , and a transaction processing unit 430 .

When the recording processing unit 410 receives the cipher text pair from the power transaction server 300 , it checks the requestor of the cipher text pair and records the cipher text pair in the seller list or the buyer list.

That is, the record processing unit 410 may determine whether the requester is a buyer or a seller using the received transaction method together with the ciphertext pair. The record processing unit 410 may record the cipher text pair in the seller list if the requester is a seller, and may record the cipher text pair in the buyer list if the requester is a buyer.

The comparison unit 420 finds the seller cipher text pair for the minimum value among the seller list by comparing the magnitude between the desired sales amounts encoded in the seller cipher text pair by applying a function decryption operation to the seller cipher text pairs in the seller list, and By applying a functional decryption operation to the buyer ciphertext pairs, the purchaser ciphertext pair is found for the maximum value in the buyer list by comparing the magnitude between the desired purchase amounts encoded in the buyer ciphertext pair. That is, the comparison unit 420 may perform a function decryption for identifying the ciphertext pair for the minimum value in the seller list and the ciphertext pair for the maximum value in the buyer list. Specifically, the comparison unit 420 performs function-decryption of the secret key of the seller A and the cipher text of the seller B to obtain an inner product 1 or 0 and using this to determine the magnitude relationship, repeating the work for several seller pairs, the seller list You can acquire the cryptographic pair of the seller with the minimum desired sale amount. In addition, the comparison unit 420 performs function-decryption of the secret key of the buyer A and the cipher text of the buyer B to obtain an inner product 1 or 0, and using this to determine the magnitude relationship, by repeating for several pairs of buyers, purchase from the buyer list It is possible to obtain the ciphertext pair of the buyer with the maximum desired amount.

As described above, the comparison unit 420 may obtain a pair of cipher texts of a seller having a minimum desired sale amount from the seller list, and may obtain a cipher text pair of a buyer having a maximum desired purchase amount from the buyer list.

,

라 하면, 비교부(420)는

를 이용하여 암호문 쌍

,

에 대한 함수 복호화를 진행함으로써 U가 제시한 값과 N이 제시한 값을 모르는 상태로 이들에 대한 대소 비교를 할 수 있다. 만약 U의 거래 희망 금액이 5이면,

이고, N의 거래 희망 금액이 6이면,

일 것이므로

의 결과, 즉

와

의 내적이 1이 되어 N의 거래 희망 금액이 더 큰 것을 확인할 수 있다. 또한, N의 거래 희망 금액이 4이면,

이므로

의 결과가 0이 되어 N의 거래 희망 금액이 더 적은 것을 확인할 수 있다. 이러한 방식을 이용하여 스마트 컨트랙트 실행자는 다수 사용자의 요청들을 비교함으로써 각각 판매자 목록 중 최솟값에 대한 암호문 쌍, 구매자 목록 중 최댓값에 대한 암호문 쌍을 확인할 수 있다. 이때, 최솟값과 최댓값이 무엇인지는 알 수 없을 수 있다.For example, the ciphertext pairs of two users U and N that you want to compare in the seller list or the buyer list

,

If , the comparison unit 420 is

ciphertext pair using

,

By performing function decoding for , it is possible to compare the magnitudes of the values presented by U and the values presented by N without knowing them. If U's desired transaction amount is 5,

and if the desired transaction amount of N is 6,

because it will be

the result of, i.e.

Wow

It can be confirmed that the dot product of N becomes 1, indicating that the desired transaction amount of N is larger. In addition, if the desired transaction amount of N is 4,

Because of

As the result of is 0, it can be confirmed that the desired transaction amount of N is smaller. By using this method, the smart contract executor can check the ciphertext pair for the minimum value in the seller list and the ciphertext pair for the maximum value in the buyer list by comparing the requests of multiple users. In this case, it may not be known what the minimum and maximum values are.

The transaction processing unit 430 function-decrypts the ciphertext pair for the minimum value in the seller list, and the ciphertext pair for the maximum value in the buyer list, what is the minimum value in the seller list, and the state does not know what the maximum value in the buyer list is to determine whether the transaction succeeds or not by only comparing the magnitudes of these, and transmits information on whether the transaction is successful to the power transaction server 300 .

The comparison operation performed by the transaction processing unit 430 may be performed in a similar manner to the comparison operation performed by the comparison unit 420 . That is, the transaction processing unit 430 function-decrypts the ciphertext pair for the minimum value in the seller list and the ciphertext pair for the maximum value in the buyer list to calculate the inner product, and whether the transaction between the seller and the buyer is successful based on the calculated inner product can be decided At this time, the transaction processing unit 430 applies a function decryption operation to the ciphertext of the ciphertext pair secret key for the minimum value among the seller list and the ciphertext of the buyer ciphertext pair for the maximum value in the buyer list, thereby encoding the first vector encoded for the minimum value in the seller list. and a result of the dot product between the second vector encoded for the maximum value in the buyer list, and if the calculated dot product is '1', the maximum value in the buyer list is greater than or equal to the minimum value in the seller list. It can be determined, and when the inner product is '0', it can be determined as a transaction failure between the seller and the buyer.

When it is determined that the transaction between the seller and the buyer is successful, the transaction processing unit 430 may transmit the seller's address and power transaction information, the buyer's address and power transaction information to the electricity transaction server 300 .

Since all the above processes are performed by the smart contract on the block chain 400, manipulation is impossible, and thus the integrity of the transaction decision process can be guaranteed. However, since all transaction amounts are encrypted, information such as a desired transaction amount or a matched amount can be protected.

4 is a diagram for explaining a blockchain-based power transaction method according to an embodiment of the present invention.

Referring to FIG. 4 , when the user device 100 receives power transaction information including a transaction method, a transaction amount, and a desired transaction amount ( S410 ), the user device 100 transmits the received power transaction information to the power transaction server 300 ( S420 ). ).

When step S420 is performed, the power transaction server 300 generates a first vector and a second vector by encoding the power transaction information (S430). That is, the power transaction server 300 may compare the desired transaction amount with the transaction amount range per unit power, and generate a first vector based on the comparison result. In addition, the power transaction server 300 may generate a second vector by one-hot encoding the desired transaction amount.

When step S430 is performed, the power transaction server 300 generates a secret key for the first vector, generates a ciphertext for the second vector (S440), and blocks the ciphertext pair including the generated secret key and the ciphertext. It is transmitted to the chain 400 and recorded (S450). That is, the power transaction server 300 generates a secret key for the first vector using a key generation algorithm, generates a cipher text for the second vector using an encryption algorithm, and then a cipher text including the secret key and the cipher text. The pair can be transmitted to the blockchain 400 . Then, the blockchain 400 checks whether the requester is a buyer or a seller using the transaction method received with the cipher text pair, records the cipher text pair in the seller list if the requester is a seller, and records the cipher text pair on the buyer list if the buyer is the buyer can be recorded in

When step S450 is performed, the blockchain 400 applies a function decryption operation to the seller ciphertext pairs in the seller list to find the seller ciphertext pair for the minimum value in the seller list, and performs a function decryption operation for the buyer ciphertext pairs in the buyer list Applied to find the buyer ciphertext pair for the maximum value in the buyer list (S460). That is, the blockchain 400 applies a function decryption operation to the seller ciphertext pairs in the seller list to compare the magnitude between the desired sales amounts encoded in the seller ciphertext pair to find the seller ciphertext pair for the minimum value in the seller list, and the buyer By applying a functional decryption operation to the buyer ciphertext pairs in the list, and comparing the magnitude between the desired purchase amounts encoded in the buyer ciphertext pair, the buyer ciphertext pair for the maximum value in the buyer list can be found.

When step S460 is performed, the block chain 400 function-decrypts the seller ciphertext pair for the minimum value and the buyer ciphertext pair for the maximum value to calculate the inner product (S470), and determines whether the transaction is successful based on the calculated inner product ( S480), the transaction success information is transmitted to the power transaction server 300 (S490). That is, the block chain 400 calculates the dot product result between the first vector encoded for the minimum value in the seller list and the second vector encoded for the maximum value in the buyer list, and when the calculated dot product is '1', in the buyer list If the maximum value of is greater than or equal to the minimum value in the seller list, it can be determined as a transaction success between the seller and the buyer, and when the dot product is '0', it can be determined as a transaction failure between the seller and the buyer.

As described above, the blockchain-based power transaction system and method according to an embodiment of the present invention encrypts and protects transaction data using a block-chain-based function encryption technique, and at the same time, a third party other than the transaction party conducts the transaction. Without knowing the content, it can contribute to the proof of the integrity of the result. In other words, since size comparison is possible in an encrypted state, even if a third party cannot confirm the transaction details, the result of the size comparison can be known, thereby solving the problem of confidentiality of the block chain.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is only exemplary, and those skilled in the art to which the art pertains can make various modifications and equivalent other embodiments therefrom. will understand Therefore, the true technical protection scope of the present invention should be defined by the following claims.

100: user device
300: power trading server
310: interface unit
320: encoding unit
330: encryption unit
340: control unit
400: Blockchain
410: record processing unit
420: comparison unit
430: transaction processing unit

Claims (18)

a user device receiving power transaction information;
a power transaction server that receives power transaction information from the user device, encodes the power transaction information, and encrypts the encoded information; and
Upon receiving the ciphertext pair from the power transaction server, input the ciphertext pair into a seller list or a buyer list, and determine whether a transaction is successful using the seller ciphertext pairs and the buyer ciphertext pairs in the seller list and the buyer list, A block chain that transmits success or failure information to the power transaction server
A blockchain-based power trading system that includes
According to claim 1,
The power transaction server,
an encoding unit generating a first vector and a second vector by encoding the desired transaction amount of the power transaction information; and
A block comprising an encryption unit for generating a secret key for the first vector, generating a cipher text for the second vector, and transmitting a cipher text pair including the generated secret key and cipher text to a block chain Chain-based power trading system.
3. The method of claim 2,
The encoding unit,
A block chain-based power trading system, characterized in that the desired transaction amount is compared with a preset transaction amount range per unit power, and a first vector and a second vector are generated by encoding the desired transaction amount based on the comparison result. .
4. The method of claim 3,
The encryption unit,
After generating a secret key for the first vector using a key generation algorithm, and generating a cipher text for the second vector using an encryption algorithm, a cipher text pair including the secret key and the cipher text is converted into the block chain. A blockchain-based power trading system characterized by transmitting.
According to claim 1,
The blockchain is
a record processing unit that, upon receiving the ciphertext pair from the power transaction server, checks the requestor of the ciphertext pair and records it in a seller list or a buyer list;
A comparison unit that finds a seller ciphertext pair for the minimum value by applying a function decryption operation to the seller ciphertext pairs of the seller list, and finds a buyer ciphertext pair for the maximum value by applying a function decryption operation to the buyer ciphertext pairs of the buyer list; and
A transaction processing unit that performs a function decryption operation on the seller ciphertext pair for the minimum value and the buyer ciphertext pair for the maximum value, determines whether the transaction is successful, and transmits the transaction success information to the power transaction server Block characterized in that it comprises a Chain-based power trading system.
6. The method of claim 5,
The comparison unit,
By applying a function decryption operation to the seller cipher text pairs of the seller list, by comparing the magnitude between the desired sales amounts encoded in the seller cipher text pair, the seller cipher text pair for the minimum value in the seller list is found, and the buyer cipher text pairs of the buyer list A block chain-based power transaction system, characterized in that by applying a function decryption operation to the purchaser cryptogram pair and comparing the magnitude between the desired purchase amounts encoded in the buyer cryptogram pair, the buyer cryptogram pair for the maximum value in the buyer list is found.
6. The method of claim 5,
The transaction processing unit,
A block chain-based power, characterized in that the seller cipher text pair for the minimum value and the buyer cipher text pair for the maximum value are function-decrypted to calculate an inner product, and based on the calculated inner product, whether a transaction between the seller and the buyer is successful or not trading system.
8. The method of claim 7,
The transaction processing unit,
By applying a functional decryption operation to the secret key of the seller ciphertext pair for the minimum value and the ciphertext of the buyer ciphertext pair for the maximum value, the first vector encoded for the minimum value in the seller list and the first vector encoded for the maximum value in the buyer list calculating the result of the dot product of the second vector, determining that the transaction between the seller and the buyer is successful when the calculated dot product is '1', and determining that the transaction fails between the seller and the buyer whose dot product is '0' A blockchain-based power trading system with
9. The method of claim 8,
The transaction processing unit,
When it is determined that the transaction between the seller and the buyer is successful, the seller's address and power transaction information, and the buyer's address and electricity transaction information are transmitted to the electricity transaction server.
when the power transaction server receives the power transaction information from the user device, encoding the power transaction information, and encrypting the encoded information; and
When the block chain receives the ciphertext pair from the power transaction server, it inputs the ciphertext pair to the seller list or the buyer list, and determines whether the transaction succeeds using the seller ciphertext pairs and the buyer ciphertext pairs in the seller list and the buyer list and transmitting transaction success information to the power transaction server.
A blockchain-based power transaction method that includes
11. The method of claim 10,
Encoding the power transaction information, and encrypting the encoded information,
generating, by the power transaction server, a first vector and a second vector by encoding the desired transaction amount of the power transaction information; and
The power transaction server generates a secret key for the first vector, generates a cipher text for the second vector, and transmits a cipher text pair including the generated secret key and cipher text to a block chain. A blockchain-based power transaction method, characterized in that.
12. The method of claim 11,
In the step of generating the first vector and the second vector,
wherein the power transaction server compares the desired transaction amount with a preset transaction amount range per unit power, and encodes the desired transaction amount based on the comparison result to generate first and second vectors Blockchain-based electricity trading method.
12. The method of claim 11,
In the step of transmitting the ciphertext pair including the generated secret key and ciphertext to the block chain,
The power transaction server generates a secret key for the first vector using a key generation algorithm, generates a cipher text for the second vector using an encryption algorithm, and then a cipher text pair including the secret key and the cipher text A block chain-based power transaction method, characterized in that it is transmitted to the block chain.
11. The method of claim 10,
Transmitting the transaction success information to the power transaction server comprises:
when the block chain receives the cipher text pair from the power transaction server, checking the requestor of the cipher text pair and recording it in a seller list or a buyer list;
The block chain applies a function decryption operation to the seller ciphertext pairs of the seller list to find the seller ciphertext pair for the minimum value, and applies the function decryption operation to the buyer ciphertext pairs in the buyer list to obtain the buyer ciphertext pair for the maximum value finding; and
The block chain performs a function decryption operation on the seller cipher text pair for the minimum value and the buyer cipher text pair for the maximum value, determining whether the transaction is successful, and transmitting information on whether the transaction is successful or not to the power transaction server A blockchain-based power trading system with
15. The method of claim 14,
In the step of finding the buyer ciphertext pair for the maximum value,
The block chain applies a function decryption operation to the seller ciphertext pairs of the seller list to find the seller ciphertext pair for the minimum value in the seller list by comparing the magnitude between the desired sales amounts encoded in the seller ciphertext pair, and the buyer A block chain-based power transaction method, characterized in that by applying a functional decryption operation to the buyer cryptogram pairs in the list to find the buyer cryptogram pair for the maximum value in the buyer list by comparing the magnitude between the desired purchase amounts encoded in the buyer cryptogram pair .
15. The method of claim 14,
In the step of transmitting the transaction success information to the power transaction server,
The block chain function-decrypts the seller cipher text pair for the minimum value and the buyer cipher text pair for the maximum value to calculate an inner product, and determines whether a transaction between the seller and the buyer succeeds based on the calculated inner product Blockchain-based electricity trading method.
17. The method of claim 16,
In the step of transmitting the transaction success information to the power transaction server,
The block chain applies a functional decryption operation to the secret key of the seller ciphertext pair for the minimum value and the ciphertext of the buyer ciphertext pair for the maximum value, whereby the first vector encoded for the minimum value in the seller list and the maximum value in the buyer list Calculates the result of the dot product of the second vector encoded with respect to , and if the calculated dot product is '1', it is determined as a transaction success between the seller and the buyer, and as a transaction failure between the seller and the buyer whose dot product is '0' A blockchain-based power transaction method characterized by determining.
18. The method of claim 17,
When it is determined that the transaction between the seller and the buyer is successful, the block chain-based electricity transaction method, characterized in that the seller's address and power transaction information, and the buyer's address and electricity transaction information are transmitted to the electricity transaction server.

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