CN112926958A

CN112926958A - Micro-grid community safety energy transaction method based on mixed block chain

Info

Publication number: CN112926958A
Application number: CN202110299215.8A
Authority: CN
Inventors: 宋子龙; 张小红; 梁苗苗
Original assignee: Jiangxi University of Science and Technology
Current assignee: Jiangxi University of Science and Technology
Priority date: 2021-03-21
Filing date: 2021-03-21
Publication date: 2021-06-08

Abstract

A microgrid community security energy transaction method based on a mixed block chain comprises transaction alliance chain construction, microgrid identity private chain construction and user public and private key pair acquisition; the identity verification of the buyer or the seller is realized based on the identity-based proxy signcryption algorithm; based on a reputation evaluation algorithm of user behaviors, realizing management of reputation scores of buyers or sellers; and the transaction of a continuous bilateral auction mechanism based on the reputation realizes the collection, interaction, sharing and storage of user information. The invention guarantees privacy and safety of the energy transaction of the microgrid community through a mixed block chain technology, provides a low-cost, open and transparent information and transaction platform for the microgrid, and guarantees traceability, tamper resistance, privacy and the like of data.

Description

Micro-grid community safety energy transaction method based on mixed block chain

Technical Field

The invention belongs to the safe transaction of Micro Grid (MG) community internal energy, and relates to a block chain technology in the field of information safety and a proxy signcryption technology based on bilinear pairing property and user identity on an elliptic curve.

Background

The energy source is a material resource which can provide certain form of energy for human beings in nature, such as common light, heat, power and other energy, and with the continuous progress of science and technology, various practical electric appliances can conveniently convert electric energy into various energy required by human beings in production and life. The existing primary energy mainly comprises fossil energy, light energy, wind energy, water energy and the like, and the electric energy is obtained by converting the primary energy. The traditional conversion method is thermal power generation, namely, electric energy is generated by burning fossil fuel, but the method has the problems of low efficiency and serious environmental pollution. Considering the importance of environmental protection, Distributed Energy Resources (DER) with the characteristics of low loss, low pollution, good system economy and the like are widely accepted.

Since the number of residents and industrial users who can bear the deployment cost of DER such as solar photovoltaic panels, biomass power generators, micro wind turbines, and diesel engines is increasing year by year, more and more DER are deployed on the industrial and residential sides from the respective interests. However, the DER generates power intermittently and randomly subject to external conditions, reducing the reliability of power supply. For the existing power system, when a large amount of invisible and uncontrollable power generated by DER directly flows into a power grid, the problem of power flow out-of-limit is easy to occur in the whole power supply line, and the principle that the power system must have safety and reliability is seriously violated.

Two technologies of Virtual Power Plants (VPPs) and micro-grids (MGs) are provided, and a reasonable solution idea is provided for solving the DER grid connection problem. Limited by existing power transmission technologies, power transmission over long distances results in partial power loss. Near-distance, small-range MG technology is certainly a better choice for industrial and residential users with DER installed. Liuyun et al provide a Distributed robust Energy management scheme for a system consisting of a plurality of MGs in IEEE Transactions on stable Energy 2017,10(1), and treat uncertain factors generated in MG operation through an adjustable robust optimization technology, thereby realizing optimization of MG total operation cost and verifying the effectiveness of the method in a 4-MG system. Zhang Xianshun et al, in Energy 2018,165 "A cell-physical-social system with parallel learning for distributed Energy management of a micro computer, propose a new network physical social system for DER management in MG, the system has parallel learning ability, can promote the appearance of high-quality DER optimization strategy through human-computer interactive learning. Case studies show that this technique achieves DER optimization strategies faster than other heuristics. Ranjbar et al, in International transformations on electric Energy Systems 2020,30(4) "Voltage-based protection of microorganisms using decision trees algorithms", propose an MG protection method that preprocesses a Voltage waveform within one cycle using short-time Fourier transform and extracts disturbance characteristics therefrom. These features will be provided to a decision tree algorithm to discriminate fault events in the MG. Simulations show that only two or six signatures are required to detect any fault, depending on the event type. The above documents mainly focus on solving technical and economic problems of the microgrid, but further development of the microgrid requires many management problems to be solved. The existing energy operation mode mostly adopts a centralized third-party management mechanism to manage the transaction, and the management mode often has the following problems: firstly, as the DER transaction amount within the scope of jurisdiction is increased, the operation cost of a transaction center is increased, the transaction efficiency is greatly reduced, and the effective operation of a microgrid is difficult to guarantee in real time; secondly, in the energy transaction process, complete trust cannot be achieved between the transaction center and the transaction party, so that the transaction center needs to generate non-negligible overhead due to maintenance of self trust every year; in addition, a public and transparent transaction and information platform does not exist in the MG, so that the security and the effectiveness of the transaction cannot be guaranteed, and the cost required by the transaction is very high; finally, a single point of failure easily occurs in the centralized transaction center, that is, the transaction center will cause the breakdown of the whole system after being attacked maliciously, and the leaked or tampered transaction information will directly damage the property and privacy security of both parties of the transaction.

Since 2016, bitcoin (a decentered digital currency) has begun to receive widespread financial attention due to its increased economic value. Meanwhile, the academia finds that the core supporting technology, namely the block chain, has great research value besides the economic value of the bitcoin. The block chain has the characteristics of decentralization, distrust, openness and transparency and the like, along with continuous research, the application range of the block chain is not limited in the financial field any more, and a block chain technology or permission is added in the transaction process of the micro-grid to provide a new solution for the management problem. M.L.Di Silvestre et al considered the provision of a voltage regulation technology for a microgrid based on a block chain in IEEE Transactions on Industry Applications 2019,55(6) "circulation services in the energy block chain for microprocessors", which was mainly realized by solving a reactive power optimization trend and reactive power compensation, the reactive power optimization trend aims at ensuring the optimal economic planning during reactive power production, and the reactive power compensation can evaluate the contribution degree of voltage regulation. Hassan et al, in IEEE Transactions on Services Computing 2019,13(2), 'DEAL: differentiated Private Auction for Block-Based micro Energy Auction', proposed an Energy transaction Auction mechanism named as differential Private Auction, which can provide a micro-grid Based on a block chain of alliances with a moderate cost, safety and privacy Energy Auction, and experimental comparison shows that the mechanism is superior to the VCG mechanism. In Applied Energy 2020,263, "An integrated block-based Energy management platform with binary tracking for micro-computer communications", van Leeuwen et al designed An integrated Energy management platform based on block chain, which consists of three parts, namely a physical layer, An economic layer and An information layer, i.e. the Energy in the micro-grid community can be traded through a bilateral trading mechanism, and the Energy flow can be optimized by solving An optimal power flow problem. The above documents have studied block chain based microgrid systems from different technical aspects, but there is still no safe method for protecting energy transactions in the microgrid.

Disclosure of Invention

The invention aims to provide a microgrid community safe energy trading method based on a mixed block chain, so as to realize the function of guaranteeing safe trading of internal energy of a microgrid community by using a block chain technology.

The invention relates to a micro-grid community safety energy transaction method based on a mixed block chain. The identity private chain mainly comprises an authoritative center, an MG and users within the scope governed by the MG. When a user wants to perform energy transaction, identity authentication needs to be performed on an identity private chain, only the user passing the authentication can obtain transaction permission, and otherwise, the MG electric energy transaction platform cannot be used. Whether the user can pass the verification of the identity private chain depends on the reputation of the user, and when the reputation is 0, the user can not use the energy transaction function any more. In order to effectively evaluate the reputation of the user, a reputation evaluation algorithm based on user behaviors is provided, and the algorithm is divided into a buyer behavior reputation evaluation algorithm and a seller behavior reputation evaluation algorithm due to the fact that two identities of a buyer and a seller exist in energy transaction, and all behaviors of the user can be objectively reflected on the reputation score of the user. The central node in the private chain is centralized in power, which gives the ability to tamper with the data, and to prevent this event, the hash digest of the private chain needs to be stored in a more secure federation chain. The trading union chain mainly comprises an authority center, an electric power trading center, all MGs, DER deployed by users in the scope of the trading union chain, an energy manager and an intelligent home manager. In the transaction process, in order to ensure confidentiality and non-repudiation of the quotation information, the DER and the intelligent home manager participating in the transaction need to continuously perform signature and encryption work on the quotation information, although the signature and encryption work can be simplified by a signature and encryption algorithm, the DER and the intelligent home manager which are limited in computing still have huge computing burden. Therefore, the signing and sealing work is carried out by using the identity-based proxy signing and sealing algorithm, namely, original information owners such as DER and smart home managers grant the processing right of the information to energy managers belonging to the same user, and the energy managers carry out the signing and sealing work. All transaction information will be recorded in the federation chain to ensure non-tamper-ability and transparency of the information.

The invention relates to a micro-grid community safe energy transaction method based on a mixed block chain technology, which comprises the following steps of:

(S01): the method comprises the steps that firstly, a trading alliance chain is established by an authority, after the trading alliance chain is established successfully, the MG goes to the authority to register registration information and establishes a private identity chain which is exclusive to the MG together with the authority. Only when the MG community to which the user belongs builds the own identity private chain, the community user can obtain a private and public key pair after the identity of the authority is checked, and the key pair is generated through an identity-based encryption algorithm. The trading alliance chain comprises all nodes in the network, and the identity private chain is constructed by each MG on the basis of the alliance chain and only comprises user nodes and authority nodes in the community range of the MG;

(S02): before the transaction begins, the identity of the buyer or the seller needs to be verified by the community user on the identity private chain, and the passed user can only obtain one identity permission to carry out the transaction. When the identity authentication is started, the system checks whether community users exist in a blacklist or not, and only the users not on the blacklist can select the transaction identity. When the user selects the seller identity, the system checks whether the user has the distributed energy and whether the seller reputation score is qualified, and only if the user has the distributed energy and the seller reputation score is qualified, the user can obtain the seller identity permission, otherwise, the transaction identity selection is required to be carried out again; when the user selects the buyer identity, the system checks whether the reputation score of the buyer is qualified, if so, the system issues the buyer identity permission, and if not, the system adds the buyer identity permission into the blacklist. When user nodes are just added, the system gives the same initial reputation scores to the user nodes, and each user has a reputation score of a buyer and a reputation score of a seller;

(S03): after the community users obtain respective trading permission, energy trading can be conducted on the trading union chain, and the trading mode is a continuous bilateral auction mechanism based on reputation. When participating in transaction auction, a direct energy participation node such as an intelligent energy home manager or DER entrusts the processing authority of data to an energy manager belonging to the same user through a proxy signcryption algorithm, in order to solve the management problem of the certificate of the traditional public key facility, a proxy signcryption algorithm based on identity is adopted to generate a proxy key, and then the energy manager can sign the bidding information of each time by using the proxy key;

(S04): and after a round of transaction is finished, the central node in the identity private chain collects behavior information of the community users on the transaction alliance chain. Due to the different roles that users play when participating in transactions, these behavior information can be divided into buyer behavior information and seller behavior information. After the information collection is completed, the central node evaluates the reputation scores of the buyers or sellers in a new round of the user by using a reputation evaluation algorithm based on the user behaviors;

(S05): and the accounting node on the identity private chain packs the identity information, the transaction behavior information and the reputation of each user into a data block, and then verifies the block through the verification node, and the verified block is connected to the identity private chain. In addition, the verification node also needs to store the hash digest of the identity private chain onto the transaction federation chain. Similar to the identity private chain, the transaction information and the hash digest of the identity private chain are packaged into a data block by the preselected node in the transaction alliance chain, and only the verified block can be selected as the latest block to be added to the transaction alliance chain;

(S06): when data is stored in the blockchain, all nodes commonly store the same data information, and transaction records generated by each node are public. The block generation in the block chain also follows a transparent consensus rule, and the consensus node processes the transaction information according to a specific consensus mode and generates a new block, so that the data transparency is realized. The blocks on the block chain are generated according to the time sequence, all transactions are public due to the transparency of the block chain, and when disputes occur to a certain transaction, the transaction information can be traced according to the conditions.

The identity-based encryption algorithm of the step (S01) of the present invention includes the following specific contents:

(1) and (5) setting a system.

Setup(1^l) → (GP, MSK): the authority executes the algorithm, inputs the system security parameter l, and outputs the specific system public parameter GP and the master key MSK.

(2) And generating a key.

KGen(GP,MSK,ID)→(PK_ID,SK_ID): authority inputs system public parameter GP, master key MSK and user ID E (0,1)^*And outputting corresponding public and private key Pair (PK)_ID,SK_ID)。

(3) And (4) encrypting.

Enc(GP,PK_IDM) → C: the information sender inputs the system public parameter GP and the receiver public key PK_IDAnd plaintext information M, and outputs ciphertext C.

(4) And (6) decrypting.

Dec(GP,C,SK_ID) → M/. T: the cipher text receiver inputs the system public parameter G, the received cipher text C and the own private key SK_ID. If the received cipher text is the public key PK of the receiver_IDAnd (4) obtaining the encrypted information, outputting the encrypted information as plaintext information M, and otherwise, obtaining an error symbol ^ T.

The continuous bilateral auction mechanism based on reputation described in step (S03) of the present invention is as follows:

the continuous bilateral auction mechanism based on reputation mainly fuses a market segmentation mechanism based on reputation and a continuous bilateral auction mechanism, wherein the sequencing mechanism is changed on the original sequencing mechanism of the continuous bilateral auction mechanism and is specifically represented as 'price priority, reputation priority and time priority' instead of a priority value sequencing mechanism based on reputation. When a reputation-based continuous bilateral auction mechanism is used for energy auctions, the system divides the place into multiple rank lists by user reputation, with higher ranked users having more targets to match when the trade matches. In the bidding competition list constructed by the buyer, the price is sorted from high to low according to the sorting rule (descending order); in contrast, the sort rules in the seller's constructed list of offers sort the prices from low to high (ascending order). The two sorting modes are embodied as price priority, and reputation priority is performed in a similar mode when the prices are the same, and time priority is finally performed. The highest price quoted by the buyer is called the optimal buying price, the lowest price quoted by the seller is called the optimal selling price, and the buying and selling parties can be successfully matched only if the optimal buying price is greater than or equal to the optimal selling price, so that the interest maximization of each participant is realized, and the bargaining price is the average value of the optimal buying price and the optimal selling price.

The proxy signcryption algorithm described in step (S03) of the present invention includes the following specific contents:

(1) and (5) setting a system.

(2) And generating a key.

KGen(GP,MSK)→(PK_i,SK_i): the authority mechanism inputs the public parameters GP and the master key MSK of the system, and the algorithm outputs the public and private key Pairs (PK) of each user_i,SK_i) Wherein the original data owner's public-private key pair is (PK)_o,SK_o) Public and private key Pair (PK) of proxy signcrypter_p,SK_p) And public-private key Pair (PK) of message recipient_r,SK_r)。

(3) And (6) generating a request.

WGen(GP,ω,SK_o)→σ_ω: the original data owner inputs the system public parameter GP, the own private key SK_oAnd agent permission omega, algorithm output a principal book sigma_ωThe original data owner needs to store (omega, sigma)_ω) And sending the information to the proxy signcrypter.

(4) And (5) signing and sealing the proxy.

PSigc(GP,ω,σ_ω,M,SK_p,PK_r) → σ: the proxy signcrypter inputs system parameters GP, proxy permission omega and attorney book sigma_ωPrivate key SK owned by itself_pThe public key PK of the receiver_rAnd a message M, the algorithm outputs a ciphertext sigma.

(5) And (5) unlocking the signcryption.

UnSigc(GP,ω,σ,SK_r,PK₀,PK_p) → M/. T: the message receiver inputs system parameters GP, agent permission omega, cipher text sigma and own private key SK_rOriginal data owner public key PK_oAnd a proxy signcrypter public key PK_pIf the ciphertext sigma is legal, the algorithm outputs a message M, otherwise an error symbol is output.

The identity-based proxy signcryption algorithm described in step (S03) of the present invention comprises the following details:

(1) and (5) setting a system.

(2) And generating a key.

KGen(GP,MSK,ID)→(PK_ID,SK_ID): authority inputs system public parameter GP, master key MSK and user ID E (0,1)^*And outputting corresponding public and private key Pair (PK)_ID,SK_ID) Wherein the original data owner's public-private key pair is (PK)_o,SK_o) Public and private key Pair (PK) of proxy signcrypter_p,SK_p) And public-private key Pair (PK) of message recipient_r,SK_r)。

(3) Proxy key generation.

PKGen(GP,ω,SK_o,SK_p)→PSK_op: community user input system common parameter GP, proxy permission ω, original data owner andprivate key (SK) of proxy signcrypter_o,SK_p) Algorithm output proxy key PSK_op。

(4) And (5) signing and sealing the proxy.

PSigc(GP,ω,M,PK_r,PSK_op,SK_p) → σ: the proxy signcrypter inputs system parameters GP, proxy permission omega, message M, and recipient public key PK_rProxy key PSK_opPrivate key SK owned by itself_pAnd outputting the ciphertext sigma by the algorithm.

(5) And (5) unlocking the signcryption.

UnSigc(GP,σ,SK_r,PK_r,PK_o,PK_p) → M/. T: the message receiver inputs system parameters GP, cipher text sigma, and its own public and private key Pair (PK)_r,SK_r) Original data owner public key PK_oAnd a proxy signcrypter public key PK_pIf the ciphertext sigma is legal, the algorithm outputs a message M, otherwise an error symbol is output.

The reputation evaluation algorithm based on user behavior in step (S04) of the present invention is as follows:

(1) buyer behavior reputation evaluation algorithm.

Buyers in the MG community mainly comprise consumers needing to purchase energy, and when the sellers of the laborers are honored as 0 or the DER power supply of the laborers is difficult to meet the needs of the buyers, the laborers also belong to one of the buyers. In the buyer behavior reputation evaluation algorithm, there are three events that affect the buyer reputation evaluation, namely default event, demand response event and block generation event, and the reputation scores generated by the three events are respectively called the buyer contract reputation score

Demand response reputation score

And consensus reputation scores

When the round of transaction is finished, the latest reputation score R of the buyer_iEqualing transactionsReputation score at the outset

And adding reputation scores generated by the three types of events, as shown in formula (1):

where R is a response judgment value, when buyer i qualifies for a response, R is 1, otherwise, R is 0.

(2) A seller behavior reputation evaluation algorithm.

The seller in the MG community only has a destroyer, three events influencing the reputation of the seller exist in the behavior reputation evaluation algorithm of the seller, the events are respectively a default event, a feedback event and a block generation event, and reputation scores generated by the three events are respectively called as contract reputation scores of the seller

Feedback reputation score

And consensus reputation scores

When the round of transaction is finished, the latest reputation score R of the seller_jEqual to reputation score R 'at the beginning of the transaction'_jAdding the reputation scores generated by the three types of events as shown in formula (2)

The invention relates to a micro-grid community safe energy transaction method based on a mixed block chain technology. For the type of the adopted block chain, the public chain allows the nodes in the whole network to participate, the safety is highest, but the public chain is deployed, so that a large amount of resources are sacrificed, and the characteristics of low expansibility and weak data throughput of the public chain do not support the public chain to be applied to business transactions with large data volume; the private chain has the disadvantage of being too centralized, which makes the private chain suitable for information sharing within a single entity, but not for storing transaction information involving multiple entities; the alliance chain is a compromise between the public chain and the private chain, and has no extreme disadvantages on the premise of keeping the advantages of the two block chains, so that the alliance chain is the most common block chain in the existing block chain application. For the energy transaction of the micro-grid community, because the transfer of digital property is involved, a block chain with a higher security level is needed, the time consumption of a public chain is too much, a private chain has the risk of data tampering of a central node, and a block chain of a alliance naturally becomes an optimal choice. In practical application, the single chain is difficult to provide effective user identity management function, and is easy to provide opportunities for lawbreakers to do malicious work. Therefore, the invention is also provided with an identity chain outside the transaction chain to carry out the authentication and management of the identity of the transactor. In the operation process of the micro-grid, one micro-grid community can be used as an entity, and common transactions are carried out in the community, so that each micro-grid community can establish an identity chain belonging to the micro-grid community to manage traders, and based on the characteristics, the micro-grid can adopt a private chain as a basic framework of the identity chain. In order to solve the data tampering problem on the private chain, the hash abstract of the private chain is stored in a transaction alliance chain, and the security of the private chain data is guaranteed by means of the security of the alliance chain. In the identity private chain, the invention adopts a strong leading type Raft consensus mechanism which can ensure the rapid generation of the data block. In a trade union chain, the invention adopts a reputation-based Byzantine fault-tolerant algorithm consensus mechanism, and even if some abnormal nodes exist in the system, the final result cannot be influenced by the algorithm.

The invention guarantees privacy and safety of the energy transaction of the microgrid community through a mixed block chain technology, and provides a low-cost, public and transparent information and transaction platform for the microgrid community. When the transaction is started, the identity of the user is authenticated by using the identity private chain, and the reputation of the user is closely related to the result of the identity authentication. The authenticated user can perform energy transaction on a transaction alliance chain, and the transaction adopts a continuous bilateral auction mechanism based on the reputation, so that the mechanism allows the user to continuously update the quotation in the auction process, and the influence of the reputation score can be improved. In order to guarantee confidentiality and non-repudiation of the quotation information, an identity-based proxy signcryption technology is adopted, the algorithm allows a transaction participant with limited computing power to delegate all information processing rights to a proxy signcrypter with stronger computing power, and the legal utility of information signed by the proxy signcrypter is equal to that of the original data signcrypter personally signed. After the transaction is finished, all behavior information of community users can be collected, all behaviors of the users can be objectively reflected on reputation scores of the users by a reputation evaluation algorithm based on user behaviors, and the higher the reputation of the users is, the more benefits are obtained, which is beneficial to forming good market behaviors.

Drawings

FIG. 1 is a basic microgrid architecture provided by CERTS, in which

In order to be the point of common coupling,

is an energy management device, and is characterized in that,

in order to provide a separation device, the separation device is provided with a plurality of separation devices,

in order to be a circuit breaker, the circuit breaker is provided with a power supply,

in order to be a power-voltage controller,

in order to be a thermal load,

is a micro power supply.

FIG. 2 is a diagram of a microgrid data storage based on a hybrid block chain frameworkAnd the shared model is used for sharing the model,

in which a block of a federation chain is,

is a block of a private chain, which is,

for the patients of both birth and consumption,

in order for the consumer to be able to,

for the purpose of generating electricity by wind power,

in order to generate electricity by photovoltaic power generation,

is a fuel cell and is characterized in that,

is an energy manager.

Fig. 3 is a flow chart of building and joining an identity private chain.

Fig. 4 is a flow chart of identity authentication.

Fig. 5 is a secure transaction model based on a chain of transaction associations.

FIG. 6 is a simplified PBFT algorithm consensus flow diagram.

Detailed Description

The invention will be further explained with reference to the drawings and the specific embodiments.

The earliest concept of microgrid was proposed by the american society for Electric Reliability Technology Solutions (CERTS), and is also the most authoritative one. The key feature of the CERTS microgrid is that it can exist as a self-controlled entity with autonomy independence in the power distribution system, in other words, the microgrid cannot be distinguished from the legitimate customer sites from the power grid, and its basic structure is shown in fig. 1. The invention adopts a 1+ N mixed block chain framework to realize the safe transaction of the microgrid, namely, one alliance transaction chain and N identity private chains exist in the whole microgrid, and N is determined by the number of the existing microgrid.

1. The model design of the invention.

Referring to fig. 2, specific parameters are defined as follows for the overall structure of the present invention:

the nodes of the birth and the extinction: the producer node is a community user node provided with DER (distributed power supply), distributed energy storage or controllable load and the like, and for the producer node, when the producer node has redundant energy, the producer node can be used as a seller to participate in energy transaction on a alliance chain; when the DER deployed by the node is difficult to satisfy self electricity utilization, the nodes of the producers and the consumers can participate in energy transactions as buyers like ordinary nodes of the consumers. It should be noted that when the seller reputation of the deputy node is 0, the deputy node can only exist in the network as a normal consumer node. The producer and consumer nodes are mainly responsible for providing energy for the consumer nodes, and the consumer nodes need to pay corresponding rewards to the producer and consumer nodes.

The consumer node: the consumer node is a community user node provided with an intelligent home manager, and is different from a producer node and a consumer node, the consumer node can only participate in energy transaction on a alliance chain by using the identity of a buyer, and when the reputation of the consumer node is 0, the MG energy transaction platform refuses the consumer node to participate in the energy transaction. After each transaction, the consumer node may perform power supply quality of service feedback on the producer and consumer nodes that provide energy to the consumer node, which feedback will affect the reputation score of the producer and consumer nodes.

A microgrid node: the microgrid node is an initiator for constructing an identity private chain, and only if the microgrid node successfully constructs the own identity private chain on the basis of a transaction alliance chain, community users in the jurisdiction range can join the energy transaction network. On the self-built identity private chain, the microgrid node is used as a central node to be responsible for generating blocks, and is also required to be responsible for running a reputation evaluation algorithm based on user behaviors to evaluate the reputation of the user after each round of transaction. In the trade alliance chain, the microgrid node exists as an energy auctioneer and is mainly responsible for running a reputation-based continuous bilateral auction mechanism to perform trade matching on producer and consumer nodes.

A trusted authority node: the node is considered most secure and trusted. In the present invention, it refers to an authority and an electric power trading center. Authorities exist in both the private chain of identities and the federation chain of transactions, whose main role is to verify node identity information and generate a private-private key pair for the passing nodes. In addition, the selection of the consensus committee in the federation chain of trades is performed by an authority. The electricity trading center exists only in the trade union chain, and exists in the energy trading process as an energy balancer. When the auction is finished, if the energy balance is not achieved in the MG community, the MG needs to send an energy balance request to the electric power trading center, and the electric power trading center needs to actively respond to the request of the MG.

The symbols used in the present invention are shown in table 1:

TABLE 1 symbols used in the invention

2. The identity private chain construction and joining process of the present invention.

When a user wants to perform energy transaction, identity authentication needs to be performed on an identity private chain, only the authenticated user can obtain transaction permission, and otherwise, the MG electric energy transaction platform cannot be used. For the community users who use the platform for the first time, registration of their identity information is first required, so that the opportunity to join the identity private chain is provided (S01). The detailed process of building and joining the identity private chain is shown in fig. 3, wherein steps 1-3 belong to the building process of the identity private chain, and steps 4-7 are the joining process of the community user node.

(1) And constructing a flow.

In the construction process, step 1 represents that the MG manager sends an identity private chain construction application to the authority, where the application includes identity information of the MG community, maximum power limit, and divided jurisdiction areas. And (3) after receiving the application of the MG, the authority checks the application, and after the checking is passed, the authority returns success information to the MG and invites the MG to build an identity private chain specially belonging to the MG community, which is the meaning expressed in the step (2). And step 3 shows that the MG and the authority jointly build a private chain.

(2) Adding the process.

After the identity private chain is successfully constructed, the community user can apply to join the private chain. In the first step of the joining process, that is, step 4, the community user needs to send registration information to an authority, which is different from the consumer, and the registration information of the producer and the consumer not only includes identity information that the consumer should send, but also needs to provide detailed deployed DER information. Receiving the registration information of the community user, carefully verifying the information by the authority, encrypting and uploading the information passing the verification to a private chain of the community to which the user belongs, then generating and issuing an exclusive key for the user by the authority, and the steps 5 and 6 are the process. After receiving the private key, the user can formally join the private chain of the identity according to the private key, as shown in step 7.

3. The identity authentication process of the present invention.

In the invention, the successful joining of the identity private chain does not mean that the MG energy trading platform can be used for energy trading, and the energy trading can be formally carried out on the trading union chain only after the trading license is obtained on the identity private chain. To obtain transaction approval, authentication must be performed on the identity private chain, e.g., S02.

Fig. 4 is an identity authentication flow chart, and it can be known that, in the identity authentication, the system will first check whether the user node ID exists in the blacklist BL, and if so, the system will refuse to use the energy transaction function, otherwise, the system will continue the next step. The user node then selects the role it plays on the transaction federation chain, where only the seller and buyer roles are selectable. When a seller is selected, the system checks whether the user node has DER authenticated by an authority, if not, the system returns to the previous step and reselects the role, and if so, the system checks the reputation value of the seller of the user to which the node belongs. And re-entering the role selection process if the reputation value is equal to 0, and issuing a seller license for the role if the reputation value is not 0. When a buyer is selected, the system only needs to check the buyer reputation value of the user to which the node belongs. And if the reputation value is equal to 0, adding the user ID into the BL and refusing the BL to carry out energy transaction, and if the reputation value is not 0, issuing a buyer license for the BL. Finally, the user obtaining the seller or buyer license can conduct the energy transaction on the transaction federation chain by virtue of the license. For the destroyer, the seller identity can be selected for the transaction, and the buyer identity can be selected for the transaction, so that the identity private chain only provides identity authentication for each user once in each round of transaction. After the transaction is finished, the system recalculates the reputation score according to the performance of each node in the transaction. For all the just joined nodes, the system will give them the same initial reputation score, and each node has a seller reputation score and a buyer reputation score, but only the destroyer can use the seller reputation score. For the depreciation with the reputation of 0 of the seller, the seller can not perform energy transaction on the TCB according to the identity of the seller and can only purchase energy as common consumers; for the users existing in the black list BL, the users cannot register again in the authority to obtain the new node identity, and the method for obtaining the transaction right again is formulated by the authority.

4. The transaction process of the present invention.

At the present stage, DER energy trading forms in the MG energy trading platform are mainly divided into two types: P2P trade and centralized clearing. The P2P transaction is a direct transaction between individuals, and the transaction is automatically executed according to a corresponding contract, but such transactions are disordered and easily cause disorder of the power system. And a third-party platform is required for unified transaction under optimized scheduling during centralized clearing, so that the risk of system disorder is reduced. Because the third-party platform has a trust problem, the centralized-output transaction mode is always a scaling problem, and the occurrence of the block chain provides a brand-new solution for the trust problem. The trading mode used in the trading alliance chain is a Continuous bilateral Auction (CDA) with centralized clearing, and the quotation information required by the Auction is transmitted by using an identity-based proxy signcryption algorithm (S03). In the conventional CDA, there are only three transaction entities, namely an auctioneer, a buyer and a seller, and there is one more electric power transaction center serving as an energy balancer in the transaction alliance chain. The secure transaction model is shown in fig. 5, and the details are as follows:

(1) and (5) initializing.

After the community user passes the identity verification of the identity private chain, the corresponding identity transaction is carried out on the transaction alliance chain according to the obtained identity permission, the user obtaining the permission of the seller plays the role of the seller, the user obtaining the permission of the buyer plays the role of the buyer, the auctioneer plays the role of the MG manager node, and the secret keys of transaction participants are all generated by an authority mechanism.

(2) And (5) collecting the quoted price.

Although the smart home manager or DER as the light node can generate the quote by itself and sign and encrypt the quote to the MG manager node, the frequent signing and encrypting work needs to consume a large amount of calculation power. In addition, multiple energy bids belonging to the same entity exist in the auction list, which increases the workload of the auction and causes unnecessary waste. The energy manager serving as the whole node can integrate the quotation information of the home manager to which the user belongs in advance, then sign and encrypt the quotation information through an identity-based proxy signing and encrypting algorithm, and finally send the signed and encrypted information to the MG management node. Therefore, the effect of the light node participating in the transaction in person is realized, and the problem caused by the light node participating in person can be solved.

(3) And (4) performing energy auction.

After receiving the proxy signcryption information from the buyer and the seller, the MG manager node performs signcryption on the proxy signcryption information. And after the signcryption is released and the quotation information is obtained, auction matching is carried out according to the quotation. In order to increase the reputation value of the user, a CDA auction mechanism based on the reputation is adopted for conducting auction, namely, the user scores are graded, the user with higher grade can be matched in a wider range, and the matching is conducted according to a matching rule of price priority, reputation priority and time priority. And (4) ending the auction, and if the energy balance is not realized in the MG community, carrying out energy trading with the electric power trading center according to the situation.

(4) Trading and clearing.

And the successfully matched community users check the transaction information, and after the transaction information is confirmed to be correct, the energy transaction is carried out according to the determined transaction contract. In the transaction process, the default user will be subjected to economic punishment, and the default behavior can cause the reputation value to be reduced. The transaction clearing needs to be carried out through unique energy coins of the system, the energy coins are generated by the electric power transaction center, when each user joins the transaction alliance chain for the first time, a certain amount of energy coins can be freely received according to the ID of each user, and each ID can be received only once.

5. The consensus process of the invention.

The system adopted by the invention is a 1+ N mixed blockchain system, which is essentially a transaction alliance chain and N identity private chains. Since there are two different block chains, the present invention employs two consensus algorithms to generate blocks simultaneously, namely the Raft consensus algorithm and the PBFT consensus algorithm, as in (S05).

(1) Consensus algorithm on identity private chain.

The private chain constructed by MG has high centralization degree and has a central node, which is contrary to the strong leadership characteristic of the Raft consensus algorithm, so the invention uses the Raft consensus algorithm on the identity private chain. The strong leading form of the Raft consensus algorithm mainly manifests as all log entries only flowing from the leader server to the backup server, which simplifies the management of the replicated logs. In the identity private chain constructed by the MG, the leader selects one node from the manager nodes of the leader by the MG to act, other unselected MG manager nodes and authoritative structure nodes serve as candidates, and the follower acts by community user nodes in the identity private chain. And when the leader fails to operate normally, a new leader is selected from the candidates, and the authority node temporarily acts as the leader only when all MG manager nodes fail. The process of generating the blocks by adopting the Raft consensus algorithm can be simplified into three steps: and in the first step, the leader node verifies the reputation data of the community users, and if the reputation data passes the verification, the leader node sends the reputation data to the energy manager nodes of all the community users for rechecking. And secondly, the energy manager node conducts a retest on the data sent by the leader node and returns a retest result to the leader node. And thirdly, the leader node packs the data passing both the examination and the re-examination into blocks and uploads the blocks to the local private chain. To prevent MG manager nodes on the private chain from tampering with the data, the chunk hash values on the private chain are uploaded to the transaction federation chain. In addition, the Raft consensus algorithm does not affect the reputation of the user.

(2) Consensus algorithms on a chain of trading associations.

The PBFT consensus algorithm is used in the trade union chain, and the PBFT consensus algorithm used in the invention is modified on the original algorithm, mainly expressed in the establishment of the consensus committee. In the original algorithm, the consensus committee is composed of preselected consensus nodes, the number of the nodes in the consensus committee is fixed, and the consensus nodes are not changed. In the modified PBFT algorithm, the consensus nodes for establishing the consensus committee are changed continuously, and when each round of transaction starts, the system reselects the consensus nodes to form a new consensus committee, and the operating time of each consensus committee is a transaction period time planned by the system. In order to promote each microgrid trading platform to keep good internal trading behavior, a system constructs a consensus committee according to the principle of 'reputation priority and quantity priority', namely, an MG community with the first rank is selected according to the selection principle, then H-1 user nodes with the highest reputation rank and an MG manager node are selected from the MG community to form the consensus committee, and H is the number of fixed nodes forming the consensus committee. The reputation priority in the selection rule refers to that the MG community with the highest reputation is selected preferentially, the reputation of the MG community is determined by the internal user, and the calculation formula is shown as follows.

In the formula, l represents the number of buyers in the MG community at the moment, and m represents the number of sellers. And if the reputations of the MG communities are the same, preferentially selecting the MG community with the largest number of users. The same MG community cannot be selected continuously and when this happens, the name is carried forward to the second name.

After the consensus committee was constructed, the intra-committee members generated blocks according to the same consensus process as the original PBFT consensus algorithm, as shown in fig. 6. The PBFT distributed consensus achievement process is divided into five stages, request, pre-prepare, commit and reply. When the request stage begins, the authority sends the request of the client to the MG manager node; after receiving the request, the algorithm enters a pre-preparation stage, and the stage requires the MG manager node to broadcast the execution sequence of the transaction to the user nodes in the consensus committee; in the preparation phase, for the received information, the user node has two different behaviors, one is to accept and forward the accepted information to each node, the other is not to do any reaction, and the node in the second state is called a byzantine node, such as a producer 2 in fig. 6. The triggering condition of the commitment stage is that (H-f) same request messages are received, if yes, the commitment messages are broadcast to the whole network, f is the number of Byzantine nodes in the consensus nodes, and f needs to satisfy that f is less than or equal to (H-1)/3; in the reply stage, the consensus node feeds back the same commitment information to the authority center after collecting the same commitment information (H-f). Verified information is packaged into blocks and uploaded to a transaction alliance chain, and besides the MG manager node, other common identification nodes can obtain reputation rewards after the blocks are generated.

6. The invention analyzes safety.

The data security of the invention is crucial to the whole MG energy trading platform, and meets the security requirements required by data trading and data storage. The associated security is as follows:

(1) privacy and confidentiality: the invention adopts two block chains of a transaction alliance chain and an identity private chain to store information, the identity information of a user is stored in the identity private chain, and an attacker cannot know the real identity information of the user from the transaction information when the user carries out transaction on the transaction alliance. To ensure the confidentiality of transaction information, we use an identity-based proxy signcryption algorithm in which offers submitted by users are encrypted using symmetric encryption keys. Nodes in the federation chain cannot decrypt the quote information contained therein without obtaining the symmetric encryption key.

(2) Transparency and traceability: the block chain is used as a shared account book, all nodes jointly store the same data information, and transaction records generated by all the nodes are public. The block generation in the block chain also follows a transparent consensus rule, and the consensus node processes the transaction information according to a specific consensus mode and generates a new block, so that the data transparency is realized. The blocks on the block chain are generated according to the time sequence, all transactions are public due to the transparency of the block chain, and when a certain transaction is questioned, the transaction information can be traced according to the conditions. .

(3) Non-tamper-proof property: the difficulty of data tampering on the block chain is related to the adopted consensus algorithm, the invention adopts the Raft consensus algorithm on the private chain, and adopts the PBFT consensus algorithm on the alliance. The central node of the private chain has strong power, and in order to prevent the central node from tampering data, the block digest of the private chain is stored in the federation chain, so the non-tampering of the scheme is mainly realized by the PBFT consensus algorithm on the federation chain. The PBFT algorithm is the most common alliance chain consensus algorithm at present, and has high expansibility and low consumption. When the PBFT algorithm is adopted, the system can still work normally even if 33% of Byzantine nodes exist in the system. In addition, the consensus nodes of the invention are selected from the high-reputation nodes, and the higher the reputation nodes obtain more benefits, so that more than one third of the high-reputation nodes are impractical to damage the stability of the system against the benefits of the high-reputation nodes.

(4) Non-repudiation: non-repudiation of information is achieved by means of digital signatures, which are broadcast between nodes and verified before being stored in the block chain, and only verified information can be stored. When transaction disputes occur, non-repudiation of transactions can be realized by tracing transaction signatures in the block chain. The identity-based proxy signcryption scheme adopted by the system can not only encrypt information, but also further sign the information. Because the entity of the transaction does not have enough calculation power to carry out frequent signing and encrypting actions, the signing and encrypting authority of the data is entrusted to a proxy signer with strong calculation power, and the signing and encrypting information of the proxy signer is equal to that of the original signer.

7. The invention will be further illustrated by the following two examples.

Example 1: after the transaction is over, the MG node collects the user behavior information and performs reputation evaluation, as in (S04).

In addition, this is also the source of reputation in FIG. 4, the detailed steps are as follows:

in the conventional centralized power supply mode, the power utilization behavior of the user always changes according to the change of the time period, and it is the change that causes the occurrence of the power utilization peak period and the power utilization valley period. The peak time generally refers to the power utilization when the power utilization behavior is concentrated and the power supply is in tension. In contrast, the low-ebb period generally refers to the period of low power consumption when the power supply is sufficient. The detailed peak-valley period is mainly divided according to the local season and the time of peak-valley load, and the peak-valley periods of different regions are slightly different, so that only three periods of the high peak period H, the average period a and the low valley period L are defined herein, and no detailed time division is given. In order to better restrict the transaction behavior of the user, the invention defines a time adaptive weight parameter eta (T) according to the peak-valley period,

in the formula, no matter the transaction time T is in the peak period or the valley period, the weight occupied by the transaction time T is greater than that of the average period, so as to enhance the power utilization importance degree of the user to the two periods and reduce the occurrence probability of poor transaction behaviors.

(1) Buyer behavior reputation evaluation algorithm.

When the buyer and seller reach an intention to trade via auction and contract for a contract, the seller starts to transmit power to the buyer, and when the actual power usage of the buyer in an agreed time slot exceeds the agreed transaction amount, the benefit of the seller suffers because the prescribed number of tokens in the contract is fixed.

Thus, the default of the contract is used as one of the buyer reputation evaluation indicators, and the buyer's contract reputation score is shown in formula (5).

In the formula (I), the compound is shown in the specification,

the contract reputation score of the buyer i after the t-1 th round of transaction is finished; t is_iTrading time for buyer i;

the actual electricity consumption of the buyer i in the transaction time slot is shown;

the amount of power agreed upon in the contract. When the buyer performs default behavior, in order to compensate for the economic loss of the seller, the buyer needs to compensate for the excess electricity consumption according to the electricity price of the electricity transaction center.

The demand response event is to balance the energy demand of the power supply system when the power utilization is in shortage, and each MG issues a demand response for reducing the energy consumption to the community and publishes the total energy value required to be reduced. The buyer obtaining the response qualification reduces the self electricity consumption according to the agreed response quantity, and the demand response reputation of the buyer is shown in the formula (6).

In the formula (I), the compound is shown in the specification,

responding the reputation score for the demand of the buyer i after the t-1 round of transaction is finished; t is_i,d.5％A duration representing less than 5% deviation of buyer i response capacity from committed capacity; t is_{i,d.5％～25％}Represents the time length when the deviation is 5% to 25%; t is_{i,d.25％～50％}Represents the time length when the deviation is 25% to 50%;

representing the total time for which the buyer i needs to respond in the t-1 th round of transaction; an r of 1 indicates that buyer i responds as requested, and an r of 0 indicates no response.

The block generation undissociated consensus algorithm is used for stimulating the nodes on the network to actively participate in the consensus process, and for the nodes participating in the consensus process, the system gives a certain amount of reputation score rewards, and the calculation formula of the consensus reputation score is shown as follows.

In the formula (I), the compound is shown in the specification,

the common reputation score of the buyer i after the t-1 th round of transaction is finished; k is a radical of_iRepresenting the number of times buyer i participates in the consensus process in the t-1 th round of transaction; the value of alpha is always greater than 0, and the specific value is determined by the block generation rate, and the two values are in inverse proportion.

In summary, before the buyer is ready to perform the t-th round transaction, the reputation value of the buyer participating in the t-th round transaction can be calculated according to equation (8).

In the formula, R_i,tRepresenting buyersi reputation value when participating in the t-th round of transaction; r_i,t-1Representing a reputation value at the time of the t-1 round; r is a judgment function, when a buyer i obtains a response qualification, R is equal to 1, otherwise, R is equal to 0; when buyer i is first involved in a transaction, its initial reputation is 50.

(2) Seller behavior reputation evaluation algorithm

When the actual power supply amount of the producer and the consumer does not reach the contract transaction amount, at the moment, in order to meet the self power consumption requirement, the buyer needs to purchase the power amount from the power transaction center, the power price of the power transaction center is usually higher than the transaction power price in the MG community, and the property loss of the buyer can be caused.

Thus, the default or non-default of the contract can also be used as one of the reputation evaluation indexes of the seller, and the contract reputation of the seller is shown in the formula (9).

In the formula (I), the compound is shown in the specification,

the contract reputation score of the seller j after the t-1 th round of transaction is finished; t is_jTransact time for seller j;

the seller j is given the actual amount of power within the transaction time slot. When seller j defaults, it subsidizes the money that buyer i spends more purchasing electricity in the electricity trading center.

The feedback event means that after the transaction between the buyer i and the seller j is finished, the buyer i needs to feed back the power supply service quality of the seller j, and the feedback is F_ijIs shown, and F_ijIs in the range of [ -0.5,0.5 [)]The feedback reputation of seller j is shown in equation (10).

In the formula (I), the compound is shown in the specification,

the feedback reputation score of the seller j after the t-1 round of transaction is finished; l is the number of buyers feeding back to the seller j; e_iIs a feedback equalization function, and is mainly used for equalizing feedback values.

E_iHas only 0 and 1, if E is desired_iIn effect, it is first necessary to calculate the average value F of the buyer's feedback_aAnd standard deviation F_sdThe calculation formulas of the two are shown in formula (11) and formula (12), respectively.

Then, according to F_aAnd F_sdThe equalization parameter ε is determined, as shown in equation (13).

ε＝F_a-F_sd (13)

Finally, E is realized by the formula (14)_iAn assignment of (2).

The block generation events of the seller and the buyer are completely consistent, and the calculation formula of the reputation score is shown as follows.

In the formula (I), the compound is shown in the specification,

the common reputation score of the seller j after the t-1 th round of transaction is finished; k is a radical of_jIndicating the number of times seller j participates in the consensus process in round t-1 transactions.

So far, we can obtain the reputation value of the seller when participating in the t-th round of transaction:

in the formula, R_j,tA reputation value representing the seller j when participating in the t-th round of transaction; r_j,t-1Representing a reputation value at the time of the t-1 round; when seller j is the first time to participate in a transaction, its initial reputation is 50.

The reputation value range of the buyer or the seller can only be [0,100], so after the reputation value of the user participating in the current round of transaction is calculated according to the formula, the reputation value range of the user should be re-assigned through the formula (17) so as to achieve the purpose of restricting the reputation value range of the user.

In the formula, R_i/j,tRepresenting the reputation value of the buyer/seller when engaged in the tth round of transaction. When the reputation value of the seller is 0, the seller can only participate in the transaction with the buyer identity. When the reputation value of the buyer is 0, the buyer is added into a blacklist and is prohibited from participating in the t-th round of transaction.

Example 2: and the energy trader signs and encrypts the quotation information and sends the quotation information to the micro-grid to implement the auction specific implementation process. I.e. the corresponding steps in fig. 5 are as follows:

(1) system set-up

Setup(1^l) → (GP, MSK): in identity-based cryptographic algorithms, keys are generated by PKGs, and our scheme will control key generation by an authority. First, the authoritative center enters the security parameters l into the system. Then, the system generates two addition cyclic groups G and G with the order p according to the safety parameter l_TAnd four hash functions H are defined₁:{0,1}^*→G，

H₃:G_T→{0,1}ⁿ，

Where n is the byte length of the information M. Regarding the cyclic group G, G is its generator, and G_TSatisfy bilinear mapping relationship e: GXG → G_T. Next, the authority randomly selects an element

As the system master key, and calculates the system public key PK_pubλ g. And finally, outputting the master key MSK and the system global parameter GP.

MSK is kept secretly by authority organization, GP publishes to whole network, all nodes can obtain the information.

(2) Key generation

KGen(GP,MSK,ID)→(PK_ID,SK_ID) Inputting a user ID E (0,1)^*And if the ID verification is not passed, the authority refuses to generate the secret key for the user. And after the verification is passed, the authority outputs a public and private key pair corresponding to the ID.

In the key generation process, each user can obtain a plurality of pairs of public and private keys, and for consumers, the energy manager and the smart home manager which are deployed in the house obtain a private and public key pair. For the producers and consumers, in addition to the energy manager and the smart home manager, the exclusive public and private key pair is obtained, and the DER deployed by the energy manager and the smart home manager is also obtained. To better explain our scheme, we define the public and private key pair of the smart home manager and DER as (PK)_ori,SK_ori) I.e. the key of the original signcrypter; defining the key of the energy manager as (PK)_proxy,SK_proxy) I.e. proxy labelA secret key. The recipient's secret key uses the public and Private Keys (PK) of the microgrid_MG,SK_MG) And (4) showing.

(3) Proxy key generation

PKGen(GP,ω,SK_ori,SK_proxy)→PSK_op: the proxy key generation process is performed by the user himself, and is divided into three steps in total. The first step is executed by an original signcrypter such as an intelligent home manager or DER, and the original signcrypter uploads an authorization book omega to a alliance chain_ori∈(0,1)^*(it records the validity period of proxy, proxy content authority, original signcrypter and identity information of proxy signcrypter), at this moment, MG needs to update each node authorization omega in the storage list in real time_oriSo as to verify the information validity in the process of de-signcryption.

Second, generating proxy authorization D_ω. Private key SK of either original signcrypter_oriOr the private key SK of the proxy signcrypter_proxyBoth belonging to the same community of users. Therefore, in this step, the community user can choose to be executed by the original signcrypter or the proxy signcrypter of the energy manager. When the user has too many initial signcryptors, it is recommended that D be generated by the original signcryptors_ω. The generation process of the proxy authorization is as follows:

s＝H₂(ω) (20)

D_ω＝sSK_ori (21)

and thirdly, generating a proxy key by the proxy signcrypter.

PSK_op＝SK_proxy+D_ω (22)

The information interaction between the proxy signcrypter and the original signcrypter is performed over the home intranet, so there is no need to verify the information from the original signcrypter.

(4) Proxy signcryption

PSigc(GP,ω_proxy,M,PK_MG,PSK_op,SK_proxy) → σ: when a user wants to participate in the auction, the proxy signcrypter to which the user belongs needs to collect the quotation information M E (0,1) from the initial signcrypterⁿAnd to do itAnd (6) finishing. Random selection by proxy signcryptor

And calculates a symmetric encryption key K

K＝H₃(e(PK_pub,PK_MG)^x) (23)

Then, a symmetric encrypted ciphertext C is calculated

Next, the proxy signer utilizes the proxy key PSK_opCarry out proxy signcryption

Finally, the proxy signcrypter outputs the information sigma ═ omega_proxyμ, C, S) and send it to MG, ω_proxyRepresenting the original signatory authority forwarded by the proxy signatory, will ω_proxyThe proxy signcryption information is put into the proxy signcryption information so that the MG can conveniently and quickly find the original signcryption corresponding to the proxy signcryption information.

(5) De-signcryption

UnSigc(GP,σ,SK_MG,PK_ori,PK_proxy) → M/. T: when the MG performs the energy auction, the price information M from the initial signcrypter, which is present in the received proxy signcryption information σ, is required, and therefore the MG needs to perform the signcryption process. If the authorization book in the proxy signcryption information is inconsistent with that sent by the original signcrypter, returning an error symbol T. Otherwise, the MG performs the following task to check the validity of the ciphertext C in the proxy signcryption information σ.

Only when mu is equal to H₄When (C, V') is established, MG receives the ciphertext C, and then calculates the symmetric encryption key

K'＝H₃(e(S,PK_MG)e(PK_proxy,SK_MG)^μ+1e(sPK_ori,SK_MG)^s) (27)

Finally, MG obtains the quotation information of the initial signcrypter

If the content of M does not belong to the authorization book omega_oriWithin a specified range, the algorithm also outputs an error symbol ″.

Claims

1. A micro-grid community safe energy transaction method based on a mixed block chain is characterized by comprising the following steps:

(S01): the method comprises the following steps that firstly, a trading alliance chain is established by an authority, after the trading alliance chain is established successfully, a micro-grid goes to the authority to register registration information and establishes a private identity chain which is exclusive to the micro-grid together with the authority; after a micro-grid community to which a user belongs builds an identity private chain, the community user obtains a special public and private key pair after identity verification of an authority, and the key pair is generated through an identity-based encryption algorithm; the trading alliance chain comprises all nodes in the network, and the identity private chain is built by each micro-grid on the basis of the alliance chain and only comprises user nodes and authority nodes in the community range of the identity private chain;

(S02): before the transaction begins, the identity of a buyer or a seller needs to be verified on an identity private chain by a community user, and the passed user can only obtain one identity permission to perform the transaction; when the identity authentication is started, the system checks whether community users exist in a blacklist or not, and only the users not on the blacklist can select transaction identities; when the user selects the seller identity, the system checks whether the user has the distributed energy and whether the seller reputation score is qualified, and only if the user has the distributed energy and the seller reputation score is qualified, the user can obtain the seller identity permission, otherwise, the transaction identity selection is required to be carried out again; when the user selects the buyer identity, the system checks whether the reputation score of the buyer is qualified, if so, the system issues a buyer identity license, and if not, the system adds the buyer identity license into a blacklist; when user nodes are just added, the system gives the same initial reputation scores to the user nodes, and each user has a buyer reputation score and a seller reputation score respectively;

(S03): after the community users obtain respective trading permission, energy trading can be carried out on the trading union chain, and the trading mode is a continuous bilateral auction mechanism based on reputation; when participating in a transaction auction, the intelligent energy home manager or the distributed energy participation node delegates the processing authority of data to an energy manager belonging to the same user through a proxy signcryption algorithm, generates a proxy key by adopting the identity-based proxy signcryption algorithm, and then signs the quotation information of each time by using the proxy key;

(S04): after one round of transaction is finished, a central node in the identity private chain collects behavior information of community users on a transaction alliance chain; after the information collection is completed, the central node evaluates the reputation scores of the buyers or sellers in a new round of the user by using a reputation evaluation algorithm based on the user behaviors;

(S05): the accounting node on the identity private chain divides and packages the identity information, transaction behavior information and the reputation of each user into a data block, then the block is verified through the verification node, and the verified block is connected to the identity private chain; meanwhile, the verification node stores the hash abstract of the identity private chain to a transaction alliance chain; similar to the identity private chain, the transaction information and the hash digest of the identity private chain are packaged into a data block by the preselected node in the transaction alliance chain, and only the verified block can be selected as the latest block to be added to the transaction alliance chain;

(S06): when data is stored in the block chain, all nodes jointly store the same data information, and transaction records generated by each node are public; and the block generation in the block chain follows a transparent consensus rule, and the consensus node processes the transaction information according to the adopted consensus algorithm and generates a new block, so that the transparency and traceability of the transaction information are realized.

2. The method for the safe transaction of the micro-grid community based on the mixed block chain as claimed in claim 1, wherein the identity-based encryption algorithm of step (S01) comprises the following steps:

(1) system setting:

Setup(1^l) → (GP, MSK): the authority executes the algorithm, inputs the system security parameter l and outputs a specific system public parameter GP and a master key MSK;

(2) and (3) key generation:

KGen(GP,MSK,ID)→(PK_ID,SK_ID): authority inputs system public parameter GP, master key MSK and user ID E (0,1)^*And outputting corresponding public and private key Pair (PK)_ID,SK_ID)；

(3) Encryption:

Enc(GP,PK_IDm) → C: the information sender inputs the system public parameter GP and the receiver public key PK_IDAnd plaintext information M, and ciphertext C is output;

(4) and (3) decryption:

Dec(GP,C,SK_ID) → M/. T: the cipher text receiver inputs the system public parameter G, the received cipher text C and the own private key SK_ID(ii) a If the received cipher text is the public key PK of the receiver_IDAnd (4) obtaining the encrypted information, outputting the encrypted information as plaintext information M, and otherwise, obtaining an error symbol ^ T.

3. The microgrid community secure energy transaction method based on mixed block chains as claimed in claim 1, wherein the reputation-based continuous bilateral auction mechanism of step (S03) is:

fusing a market subdivision mechanism based on reputation with a continuous bilateral auction mechanism, and sorting the market subdivision mechanism based on reputation, the continuous bilateral auction mechanism according to a sorting mechanism with price priority, reputation priority and time priority on an original sorting mechanism of the continuous bilateral auction mechanism; the system is divided into a plurality of grade lists according to the reputation of the users, and the higher grade users have more targets which can be matched when the transactions are matched; in the bidding competition list constructed by the buyer, the ordering rule is that prices are ordered from high to low; the ordering rules in the seller's constructed list of offers are price ordering from low to high.

4. The method of claim 1, wherein the proxy signcryption algorithm of step (S03) comprises the following steps:

(1) system setting:

Setup(1^l) → (GP, MSK): the authority executes the algorithm, inputs the system security parameter l, and outputs the specific system public parameter GP and the master key MSK;

(2) and (3) key generation:

KGen(GP,MSK)→(PK_i,SK_i): the authority inputs the public parameter GP of the system and the master key MSK, and the algorithm outputs the public and private key pair (PKi, SKi) of each user, wherein the public and private key Pair (PK) of the original data owner is_o,SK_o) Public and private key Pair (PK) of proxy signcrypter_p,SK_p) And public-private key Pair (PK) of message recipient_r,SK_r)；

(3) And (3) entrusting and generating:

WGen(GP,ω,SK_o)→σ_ω: the original data owner inputs the system public parameter GP, the own private key SK_oAnd agent permission omega, algorithm output a principal book sigma_ωThe original data owner needs to store (omega, sigma)_ω) Sending to the proxy signcrypter;

(4) and (3) proxy signcryption:

PSigc(GP,ω,σ_ω,M,SK_p,PK_r) → σ: the proxy signcrypter inputs system parameters GP, proxy permission omega and attorney book sigma_ωPrivate key SK owned by itself_pThe public key PK of the receiver_rAnd a message M, outputting a ciphertext sigma by an algorithm;

(5) and (3) de-signing and encrypting:

UnSigc(GP,ω,σ,SK_r,PK₀,PK_p) → M/. T: the message receiver inputs system parameters GP, agent permission omega, cipher text sigma and own private key SK_rOriginal data owner public key PK_oAnd a proxy signcrypter public key PK_pIf the ciphertext sigma is legal, the algorithm outputs a message M, otherwise it outputsWrong sign |.

5. The method of claim 1, wherein the identity-based proxy signcryption algorithm of step (S03) comprises the steps of:

(1) system setting:

(2) and (3) key generation:

KGen(GP,MSK,ID)→(PK_ID,SK_ID): authority inputs system public parameter GP, master key MSK and user ID E (0,1)^*And outputting corresponding public and private key Pair (PK)_ID,SK_ID) Wherein the original data owner's public-private key pair is (PK)_o,SK_o) Public and private key Pair (PK) of proxy signcrypter_p,SK_p) And public-private key Pair (PK) of message recipient_r,SK_r)；

(3) Generating a proxy key:

PKGen(GP,ω,SK_o,SK_p)→PSK_op: community user input system public parameter GP, proxy permission omega, private keys (SK) of original data owner and proxy signcrypter belonging to the community user input system_o,SK_p) Algorithm output proxy key PSK_op；

(4) And (3) proxy signcryption:

PSigc(GP,ω,M,PK_r,PSK_op,SK_p) → σ: the proxy signcrypter inputs system parameters GP, proxy permission omega, message M, and recipient public key PK_rProxy key PSK_opPrivate key SK owned by itself_pOutputting a ciphertext sigma by an algorithm;

(5) and (3) de-signing and encrypting:

6. The method of claim 1, wherein the reputation evaluation algorithm based on user behavior in step (S04) comprises:

(1) buyer behavior reputation evaluation algorithm:

buyers in the micro-grid community mainly comprise consumers needing to purchase energy, and when the sellers of the producers and the consumers are honored as 0 or the distributed energy power supply of the sellers is difficult to meet the needs of the sellers, the producers and the consumers also belong to one buyer; in the buyer behavior reputation evaluation algorithm, the events influencing the buyer reputation evaluation are default events, demand response events and block generation events, and the reputation scores generated by the three events are respectively called the contract reputation scores of the buyer

Demand response reputation score

And consensus reputation scores

When the round of transaction is finished, the latest reputation score R of the buyer_iEqual to reputation score R 'at the beginning of the transaction'_iAnd adding reputation scores generated by the three types of events, as shown in formula (1):

(2) Seller behavior reputation evaluation algorithm:

seller in microgrid community only has either a producer or a consumerIn the seller behavior reputation evaluation algorithm, three events which influence the reputation of the seller exist, namely, a default event, a feedback event and a block generation event, and the reputation scores generated by the three events are called the contract reputation scores of the seller respectively

Feedback reputation score

And consensus reputation scores

When the round of transaction is finished, the latest reputation score R of the seller_jEqual to reputation score R 'at the beginning of the transaction'_jAnd adding reputation scores generated by the three types of events, as shown in formula (2):