Electric vehicle identity authentication method, system, device and storage medium

Abstract

The present invention discloses an electric vehicle identity authentication method, system, device and storage medium. The method obtains registration messages of electric vehicles and edge servers joining V2G networks; obtains the pseudonym of electric vehicles through a cloud computing center according to the registration messages of electric vehicles; calculates and obtains the reputation value of local aggregators, selects the first local aggregator with a reputation value greater than a preset value for communication; obtains the transaction request of the electric vehicle, and sends the transaction message report of the electric vehicle to the edge server through the first local aggregator; sends a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center collaboratively authenticates the registration message of the electric vehicle and obtains a transaction token; based on the transaction token, the electric vehicle and the charging station mutually authenticate and complete the transaction, and the pseudonym of the electric vehicle is updated. The present invention can prevent the continuous monitoring of malicious electric vehicles, improve the security of electric vehicle transactions, and reduce computing overhead.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to an electric vehicle identity authentication method, system, device and storage medium. Background Art

[0002] With the growing demand for energy-saving and environmentally friendly transportation solutions, electric vehicles have become an emerging means of transportation. However, a large number of safety issues have affected its further development.

[0003] Existing schemes use identity-based restricted partial blind signature technology to implement authentication schemes. These schemes are based on symmetric bilinear pairing and have high computational costs. Local aggregators may tamper with transaction records, and malicious electric vehicles may continuously monitor electricity transactions to infer the lifestyle of electric vehicle users. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an electric vehicle identity authentication method, system, device and storage medium, which can prevent malicious electric vehicles from continuously monitoring, improve the security of electric vehicle transactions, and reduce computing overhead.

[0005] In a first aspect, an embodiment of the present invention provides an electric vehicle identity authentication method, the method comprising:

[0006] Obtain registration messages of electric vehicles and edge servers joining the V2G network;

[0007] According to the registration information of the electric vehicle, a pseudonym of the electric vehicle is obtained through a cloud computing center;

[0008] Calculate and obtain the reputation value of the local aggregator, and select a first local aggregator whose reputation value is greater than a preset value for communication;

[0009] Obtaining a transaction request of the electric vehicle, sending a transaction message report of the electric vehicle to the edge server through the first local aggregator, and verifying the transaction message report through the edge server;

[0010] Sending a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center collaboratively authenticates the registration message of the electric vehicle and obtains a transaction token;

[0011] According to the transaction token, the electric vehicle and the charging station authenticate each other and complete the transaction, and the pseudonym of the electric vehicle is updated.

[0012] Compared with the prior art, the first aspect of the present invention has the following beneficial effects:

[0013] The method obtains the registration message of the electric vehicle and the edge server to join the V2G network; according to the registration message of the electric vehicle, the pseudonym of the electric vehicle is obtained through the cloud computing center; in order to prevent the local aggregator from malicious tampering, the reputation value of the local aggregator is calculated and obtained, and the first local aggregator with a reputation value greater than a preset value is selected for communication; in order to reduce the load of the cloud computing center and reduce the computing overhead, the transaction message report of the electric vehicle is sent to the edge server through the first local aggregator, and the transaction message report is verified by the edge server; in order to prevent malicious electric vehicles from participating in power transactions, a collaborative authentication request is sent to the cloud computing center through the edge server, so that the cloud computing center collaboratively authenticates the registration message of the electric vehicle and obtains a transaction token; according to the transaction token, the electric vehicle and the charging station mutually authenticate and complete the transaction, and the pseudonym of the electric vehicle is updated. The method selects the first local aggregator with a reputation value greater than a preset value for communication, and after the transaction is completed, the pseudonym of the electric vehicle is updated, which can prevent the continuous monitoring of malicious electric vehicles, improve the security of electric vehicle transactions, and reduce computing overhead.

[0014] According to some embodiments of the present invention, the electric vehicle identity authentication method further includes:

[0015] Register the electric vehicle in the V2G network and select a random number sk ev ∈Z p as the private key of the electric vehicle, and calculate as a public key of the electric vehicle;

[0016] The real identity information of the electric vehicle is sent to the cloud computing center, and the cloud computing center obtains the pseudonym of the electric vehicle through the following formula:

[0017]

[0018] Among them, select a hash key key i ∈X,ID ev Indicates the real identity message of the electric vehicle, VT i Indicates the validity period of the electric vehicle pseudonym, Represents the hash function, PID ev represents the pseudonym of the electric vehicle, ‖ represents a connection symbol, and Z p The field Z representing prime numbers p p ;

[0019] The cloud computing center calculates O ev =H(PID ev ), O ev Represents the hash value and sends O ev Sending to the electric vehicle;

[0020] The electric vehicle will <H[O ev ,ID ev ,sk ev ,pk ev ,PID ev ]⊕β ev ,pk ev >Stored in a tamper-resistant device, where sk ev Represents the private key of the electric vehicle, pk ev Represents the public key of the electric vehicle.

[0021] According to some embodiments of the present invention, the electric vehicle identity authentication method further includes:

[0022] Register the edge server in the V2G network and select a random number sk es ∈Z p As the private key of the edge server, calculate as a public key of the edge server;

[0023] Sending a request to join the V2G network to the edge server through the electric vehicle;

[0024] Get the fingerprint of the user corresponding to the electric car and generate a random number n1∈Z p ;

[0025] According to the user's fingerprint and the random number n1∈Z p , obtain message m1 through the following formula:

[0026] sk ev =sk e ' v ⊕h(β ev )

[0027]

[0028] vm1=h(PID ev ‖n1‖sk ev ‖T1)

[0029] Among them, sk e ' v represents the private key after XOR encryption, h(β ev ) represents the fingerprint of the user, SK represents the session key between the electric vehicle and the edge server, Indicates that the electric vehicle sends a request to the edge server to join the V2G network, represents the request after XOR encryption, T1 represents the timestamp of message m1, and the message m1 is m1:{PID ev ,n1,vm1,T1}, vm1 represents the hash value for verifying the message m1, and ⊕ represents the XOR operator;

[0030] Sending the message m1 to the edge server through the electric car, so that the edge server sends a group signature request to the cloud computing center;

[0031] According to the group signature request, the group public key and the group private key are divided by the cloud computing center, and the edge server is used as a group administrator to manage all electric vehicles within the communication range of the edge server.

[0032] According to some embodiments of the present invention, the calculating and obtaining the reputation value of the local aggregator, and selecting the first local aggregator whose reputation value is greater than a preset value for communication, includes:

[0033] The local aggregator is scored for each registered electric vehicle to obtain the first reputation value;

[0034] Accumulating the first reputation value obtained by each registered electric vehicle to obtain the reputation value of the local aggregator;

[0035] The reputation value of the local aggregator is compared with a preset value, and a first local aggregator whose reputation value of the local aggregator is greater than the preset value is selected for communication.

[0036] According to some embodiments of the present invention, obtaining the transaction request of the electric vehicle, sending the transaction message report of the electric vehicle to the edge server through the first local aggregator, and verifying the transaction message report through the edge server includes:

[0037] The transaction request of the electric vehicle is obtained. If the electric vehicle passes the verification of the cloud computing center, the transaction message report of the electric vehicle is obtained in the following manner:

[0038] Select a random number r0∈Z p For transaction message m ev To encrypt:

[0039]

[0040] Among them, em ev Indicates encrypted transaction message,

[0041] Select a random number u0 to randomize the signature:

[0042]

[0043] in, represents the signature resolution of the electric vehicle, Represents a randomized signature;

[0044] Select a random number t0 and calculate the following formula:

[0045]

[0046] s0←u0+c ev ·st ev

[0047] Where H(.) represents a hash function, e(·) represents a bilinear pairing, and st ev ∈Z p Indicates a secret;

[0048] Output an encrypted transaction message em ev Group signature on Then the transaction message report of the electric vehicle is:

[0049]

[0050] Among them, ms ev A transaction message report indicating the electric vehicle;

[0051] The transaction message report is sent to the edge server through the first local aggregator, and the transaction message report is verified in the following manner:

[0052] According to the transaction message report, the edge server Verify the transaction message report and check

[0053] According to some embodiments of the present invention, sending a collaborative authentication request to the cloud computing center through the edge server so that the cloud computing center collaboratively authenticates the registration message of the electric vehicle and obtains a transaction token includes:

[0054] Send a collaborative authentication request through the edge server es Go to the cloud computing center and enter the private key α of the edge server es =h(sk es ), and generate a random number n5∈Z p , obtain the message m5 of the edge server in the following manner:

[0055]

[0056] requestes =request′ es ⊕h(sk es )

[0057] vm5=h(ID es ‖n5‖sk es ‖T5)

[0058] Wherein, SK represents the session key between the edge server and the cloud computing center, request es Indicates that the electric vehicle sends a request to the edge server to join the V2G network, request′ es represents the request after XOR encryption, T5 represents the timestamp of message m5, and the message m5 is m5:{ID es ,n5,vm5,T5}, vm5 represents the hash value of verifying the message m5, ID es A real identity message representing the edge server;

[0059] The message m5 is sent to the cloud computing center through the edge server, and a random number n6∈Z is generated. p :

[0060]

[0061] vm6=h(ID cc ‖n6‖T6)

[0062] Wherein, SK represents the session key between the edge server and the cloud computing center, T6 represents the timestamp of message m6, the message m6 is m6:{m5,n6,vm6,T6}, vm6 represents the hash value for verifying the message m6, ID cc A real identity message representing the cloud computing center;

[0063] The registration message of the electric vehicle is checked through the cloud computing center. For the electric vehicle with the registration message, the cloud computing center sends a transaction token Token and a message m6:{m5,n6,vm6,T6} to the electric vehicle.

[0064] According to some embodiments of the present invention, the step of updating the pseudonym of the electric vehicle based on the transaction token so that the electric vehicle and the charging station authenticate each other and complete the transaction includes:

[0065] The transaction token Token is input through the electric vehicle, and α is calculated ev =h(Token), generate a random number n7∈Z p :

[0066] skev =sk e ' v ⊕h(Token)

[0067] vm7=h(PID ev ‖n7‖sk ev ‖T7)

[0068] Among them, sk ev Represents the private key of the electric vehicle, sk e ' v represents the private key after XOR encryption, T7 represents the timestamp of message m7, and the message m7 is m7:{PID ev ,n7,vm7,T7}, vm7 represents the hash value of the message m7 for verification, PID ev a pseudonym for the electric vehicle;

[0069] The electric vehicle sends the message m7: {PID ev ,n7,vm7,T7} is sent to the charging station to generate a random number n8∈Z p :

[0070] vm8=h(ID cs ‖n8‖k ce ‖T8)

[0071] Wherein, T8 represents the timestamp of message m8, and the message m8 is m8:{m7,ID cs ,n8,vm8,T8}, vm8 represents the hash value of verifying the message m8, ID cs A message indicating the real identity of the charging station;

[0072] The charging station sends the message m8:{m7,ID cs ,n8,vm8,T8} is sent to the cloud computing center. When the message m8 arrives, the cloud computing center locates the pseudonymous PID of the electric vehicle in the database of the cloud computing center. ev ;

[0073] Generate a session key SK and a new pseudonym through the cloud computing center

[0074]

[0075] SK ev =h(ID ev ‖sk ev ‖n7)⊕SK

[0076] SK cs =h(ID cs ‖kce ‖n8)⊕SK

[0077] vm7=h(SK cs ‖k ce ‖n9)

[0078]

[0079] Where h(·) represents the hash function, n9 represents the random number, and PID ev represents a pseudonym for the electric vehicle, Indicates the updated pseudonym after XOR encryption, SK ev Represents the EV's session key, SK cs represents the session key of the charging station, k ce Represents an identifier;

[0080] A message m9 is composed through the cloud computing center: Sending the message m9 to the charging station;

[0081] After receiving vm7, the charging station verifies and calculates m7 through vm7. If the verification is successful, the charging station decrypts the session key SK=h(ID cs ‖k ce ‖n8)⊕SK cs And send a message m 10 : to the electric vehicle, after receiving vm8, the electric vehicle verifies m8 through vm8 and calculates the session key SK=h(ID ev ‖sk ev ‖n7)⊕SK ev , so that the electric vehicle and the charging station can authenticate each other and complete the transaction;

[0082] After the transaction is completed, the pseudonym of the electric vehicle is updated as follows:

[0083]

[0084] in, The pseudonym for the updated electric car, sk ev Represents the private key of the electric vehicle.

[0085] In a second aspect, an embodiment of the present invention further provides an electric vehicle identity authentication system, the system comprising:

[0086] A registration message acquisition unit, used to acquire registration messages of electric vehicles and edge servers joining the V2G network;

[0087] A pseudonym acquisition unit, used for acquiring the pseudonym of the electric vehicle through a cloud computing center according to the registration message of the electric vehicle;

[0088] an aggregator selection unit, configured to calculate and obtain a reputation value of a local aggregator, and select a first local aggregator whose reputation value is greater than a preset value for communication;

[0089] a message verification unit, configured to obtain a transaction request of the electric vehicle, send a transaction message report of the electric vehicle to the edge server through the first local aggregator, and verify the transaction message report through the edge server;

[0090] A token acquisition unit, used for sending a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center collaboratively authenticates the registration message of the electric vehicle and obtains a transaction token;

[0091] The pseudonym updating unit is used to update the pseudonym of the electric vehicle based on the transaction token so that the electric vehicle and the charging station can authenticate each other and complete the transaction.

[0092] In the third aspect, an embodiment of the present invention also provides an electric vehicle identity authentication device, comprising at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute an electric vehicle identity authentication method as described above.

[0093] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute an electric vehicle identity authentication method as described above.

[0094] It can be understood that the beneficial effects of the second to fourth aspects compared with the related art are the same as the beneficial effects of the first aspect compared with the related art. Please refer to the relevant description in the first aspect, and no further details will be given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0095] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0096] Figure 1 is a flow chart of an electric vehicle identity authentication method according to an embodiment of the present invention;

[0097] Figure 2 is a schematic diagram of system processing time comparison results according to an embodiment of the present invention;

[0098] Figure 3 is a schematic diagram of average network delay comparison results according to an embodiment of the present invention;

[0099] Figure 4 is a schematic diagram of false alarm rate comparison results according to an embodiment of the present invention;

[0100] Figure 5 It is a structural diagram of an electric vehicle identity authentication system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0101] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0102] In the description of the present invention, if there is a description of first, second, etc., it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0103] In the description of the present invention, it should be understood that descriptions involving orientation, such as orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0104] In the description of the present invention, it should be noted that, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific content of the technical solution.

[0105] To facilitate understanding by those skilled in the art, the terms in this embodiment are explained as follows:

[0106] Cloud computing center: The cloud computing center is a third-party organization that is responsible for the generation and initialization of security parameters in the entire system, which is used to verify the identity and credentials of electric vehicles. The cloud computing center is connected to multiple edge servers and works with edge servers to process electric vehicle messages. After the power transaction is completed, the cloud computing center updates the pseudonym for the electric vehicle. At the same time, it can work with edge servers to track malicious electric vehicles.

[0107] Edge Server: The edge server is distributed at the edge of the network and is responsible for processing the data transmitted by the local aggregator. The edge server acts as a group manager to handle messages from electric vehicles within the range and provides corresponding signatures when authenticating messages and tracking malicious electric vehicles.

[0108] Local Aggregator: A local aggregator is a communication intermediary through which electric vehicles communicate with edge servers, cloud computing centers, and charging stations in the network.

[0109] Electric vehicles: Each electric vehicle is equipped with an on-board unit (OBU) that is tamper-proof and can communicate with other entities in the network. Electric vehicles can interact with the grid during charging and discharging.

[0110] Charging station: Charging station is responsible for energy trading from electric vehicles to the grid in the network.

[0111] With the growing demand for energy-saving and environmentally friendly transportation solutions, electric vehicles have become an emerging means of transportation. However, a large number of safety issues have affected its further development.

[0112] Existing schemes use identity-based restricted partial blind signature technology to implement authentication schemes. These schemes are based on symmetric bilinear pairing and have high computational costs. Local aggregators may tamper with transaction records, and malicious electric vehicles may continuously monitor electricity transactions to infer the lifestyle of electric vehicle users.

[0113] To solve the above problems, the present invention obtains the registration message of the electric vehicle and the edge server to join the V2G network; according to the registration message of the electric vehicle, the pseudonym of the electric vehicle is obtained through the cloud computing center; in order to prevent the local aggregator from malicious tampering, the reputation value of the local aggregator is calculated and obtained, and the first local aggregator with a reputation value greater than the preset value is selected for communication; in order to reduce the load of the cloud computing center and reduce the computing overhead, the transaction message report of the electric vehicle is sent to the edge server through the first local aggregator, and the transaction message report is verified by the edge server; in order to prevent malicious electric vehicles from participating in power transactions, a collaborative authentication request is sent to the cloud computing center through the edge server, so that the cloud computing center collaboratively authenticates the registration message of the electric vehicle and obtains a transaction token; according to the transaction token, the electric vehicle and the charging station mutually authenticate and complete the transaction, and the pseudonym of the electric vehicle is updated. The present invention selects the first local aggregator with a reputation value greater than the preset value for communication, and after the transaction is completed, the pseudonym of the electric vehicle is updated, which can prevent the continuous monitoring of malicious electric vehicles, improve the security of electric vehicle transactions, and reduce computing overhead.

[0114] Reference Figure 1 , an embodiment of the present invention provides an electric vehicle identity authentication method, the method comprising:

[0115] Step S100: Obtain registration messages of the electric vehicle and the edge server joining the V2G network.

[0116] Specifically, the electric vehicle is registered in the V2G network, a registration message of the electric vehicle joining the V2G network is obtained, and a random number sk is selected. ev ∈Z p As the private key of the electric vehicle, calculate As the public key of the electric vehicle, Z p The field Z representing prime numbers p p ; Register the edge server in the V2G network, obtain the registration message of the edge server joining the V2G network, and select a random number sk es ∈Z p As the private key of the edge server, calculate As the public key of the edge server.

[0117] In this embodiment, after the electric vehicle and the edge server are registered, the private key and the public key corresponding to the electric vehicle and the edge server are obtained, and the private key and the public key are used to encrypt and decrypt messages to ensure the security of information.

[0118] Step S200: According to the registration information of the electric vehicle, the pseudonym of the electric vehicle is obtained through the cloud computing center.

[0119] Specifically, after the electric vehicle joins the V2G network, the real identity of the electric vehicle is obtained, and the real identity message of the electric vehicle is sent to the cloud computing center. The cloud computing center obtains the pseudonym of the electric vehicle through the following formula:

[0120]

[0121] Among them, select a hash key key i ∈X,ID ev Indicates the real identity message of electric vehicles, VT i Indicates the validity period of the electric vehicle pseudonym, Represents the hash function, PID ev represents the pseudonym of electric vehicle, ‖ represents the connector;

[0122] Compute O through cloud computing center ev =H(PID ev ), O ev Represents the hash value and sends O ev Send to electric vehicles;

[0123] Electric vehicles will <H[O ev ,ID ev ,sk ev ,pkev ,PID ev ]⊕β ev ,pk ev >Stored in a tamper-resistant device, where sk ev Represents the private key of the electric vehicle, pk ev Represents the public key of the electric vehicle.

[0124] After the edge server joins the V2G network, the electric vehicle sends a request to join the V2G network to the edge server;

[0125] Get the fingerprint of the user corresponding to the electric car and generate a random number n1∈Z p ;

[0126] According to the user's fingerprint and random number n1∈Z p , obtain message m1 through the following formula:

[0127] sk ev =sk e ' v ⊕h(β ev )

[0128]

[0129] vm1=h(PID ev ‖n1‖sk ev ‖T1)

[0130] Among them, sk e ' v represents the private key after XOR encryption, h(β ev ) represents the user’s fingerprint, SK represents the session key between the EV and the edge server, Indicates that the electric vehicle sends a request to the edge server to join the V2G network. represents the request after XOR encryption, T1 represents the timestamp of message m1, and message m1 is m1:{PID ev ,n1,vm1,T1}, vm1 represents the hash value of the verification message m1, and ⊕ represents the XOR operator;

[0131] The message m1 is sent to the edge server through the electric vehicle, so that the edge server sends a group signature request to the cloud computing center. The specific process is as follows:

[0132] The edge server generates a random number n2∈Z p , obtain the group signature request m2 in the following way:

[0133]

[0134] vm2=h(IDes ‖n2‖T2)

[0135] Among them, the group signature request m2 is m2:{m1,ID es ,n2,vm2,T2}, SK represents the session key between the EV and the edge server, ID es represents the real identity message of the edge server, T2 represents the timestamp of message m2, and vm2 represents the hash value of the verification message m2;

[0136] Send group signature request m2 to the cloud computing center through the edge server: {m1, ID es ,n2,vm2,T2}.

[0137] According to the group signature request, the cloud computing center divides the group public key and the group private key, and uses the edge server as the group administrator to manage all electric vehicles within the communication range of the edge server. The specific process is as follows:

[0138] After receiving the group signature request from the edge server, the cloud computing center selects a security parameter k and then generates a public parameter sk=(x,y) and in, $ In the cyclic group Take a random generator from above The cloud computing center generates a group public key gpk as pk and The group private key gsk is used as sk, and represents the cyclic group of three prime orders p, and e represents the bilinear map: H represents a hash function.

[0139] In this embodiment, by using XOR and hash operations to perform lightweight initialization, the computational overhead can be reduced.

[0140] Step S300: Calculate and obtain the reputation value of the local aggregator, and select a first local aggregator whose reputation value is greater than a preset value for communication.

[0141] Specifically, each registered electric vehicle scores the local aggregator to obtain a first reputation value; the first reputation values ​​obtained by each registered electric vehicle are accumulated to obtain the reputation value of the local aggregator; the reputation value of the local aggregator is compared with a preset value, and the first local aggregator whose reputation value of the local aggregator is greater than the preset value is selected for communication. The specific process is:

[0142] First, the electric car sends a query request Then the electric car generates a random number n3∈Zp , get message m3:

[0143]

[0144] vm3=h(PID ev ‖n3‖sk ev ‖s‖T3)

[0145] in, Indicates the request after XOR encryption, pk lag represents the public key of the local aggregator, T3 represents the timestamp of message m3, vm3 represents the hash value of verifying message m3, and SK represents the session key between the electric vehicle and the local aggregator.

[0146] Send message m3:{PID ev ,n3,vm3,T3} to the local aggregator, which generates a random number n4∈Z p , get message m4:

[0147]

[0148] vm4=h(ID lag ‖n4‖T4)

[0149] Among them, T4 represents the timestamp of message m4, vm4 represents the hash value of verifying message m4, SK represents the session key between the electric vehicle and the local aggregator, and ID lag Indicates the real identity message of the local aggregator.

[0150] The local aggregator returns the reputation value v ik and m4:{m3,ID lag ,n4,vm4,v lag ,T4}, where v ik represents the first reputation value of each registered electric vehicle scoring the local aggregator, v lag It represents the reputation value of the local aggregator obtained by accumulating the first reputation value obtained by each registered electric vehicle, s = s1 + s2 + ... + s U ,s1,s2,...,s U is the secret shared by the witness set U. U is the witness set for the calculation input. The process of obtaining the reputation value of the local aggregator is as follows:

[0151] Every registered electric vehicle i The description and identity of U k Sent to each party in U;

[0152] For each ev x ∈U calculates (s1,...,sU )=S U (v xk ) and send a share in U and ev x retain a share for itself;

[0153] Every ev x Get some shares from the other party in U, (r1,...,r U ) is ev x Itself and ev x Share of collection;

[0154] Every ev x Calculate t x =r1+r2+…+r U And t x Send to ev i ;

[0155] ev i Received from ev x The share of |U| and calculate For each registered electric vehicle, ik Accumulate and get the reputation value of the local aggregator.

[0156] The reputation value of the local aggregator is compared with a preset value, and a first local aggregator whose reputation value is greater than the preset value is selected for communication.

[0157] It should be noted that the preset value can be changed according to actual needs and is not specifically limited in this embodiment.

[0158] In this embodiment, the electric vehicle restores the reputation value of the local aggregator through linear secret sharing, which can prevent the local aggregator from malicious tampering.

[0159] Step S400: Obtain a transaction request of the electric vehicle, send a transaction message report of the electric vehicle to the edge server through the first local aggregator, and verify the transaction message report through the edge server.

[0160] Specifically, obtain the transaction request of the electric vehicle, and the electric vehicle selects the secret st ev ∈Z p , while sending and signature η ev ←Sign(sk ev ,τ ev ) to the cloud computing center, which verifies the equation and η ev ;

[0161] If the electric car passes the verification of the cloud computing center, it will pass the secret skev Schnorr interactive proof of knowledge, the cloud computing center selects the random number u ev ∈Z p , get the signature

[0162]

[0163] Cloud Computing Center Records Send at the same time Give the electric car and set the group private key for this electric car

[0164] Then get the electric vehicle transaction news report as follows:

[0165] Select a random number r0∈Z p For transaction message m ev To encrypt:

[0166]

[0167] Among them, em ev Represents an encrypted transaction message,

[0168] Select a random number u0 to randomize the signature:

[0169]

[0170] in, Represents the signature parsing of electric vehicles, Represents a randomized signature;

[0171] Select a random number t0 and calculate the following formula:

[0172]

[0173] s0←u0+c ev ·st ev

[0174] Where H(.) represents a hash function, e(·) represents a bilinear pairing, and st ev ∈Z p Indicates a secret;

[0175] Output an encrypted transaction message em ev Group signature on Then the transaction news report of electric vehicles is:

[0176]

[0177] Among them, ms evIndicates transaction news report of electric vehicles;

[0178] The transaction message report is sent to the edge server through the first local aggregator, and the transaction message report is verified in the following manner:

[0179] According to the transaction message report, the edge server passes Verify transaction message report and check

[0180] Edge server to message ms ev Generate the corresponding signature Then return μ es Sign for electric cars Can prove the validity of electric vehicle news.

[0181] In this embodiment, the transaction message report of the electric vehicle is sent to the edge server through the first local aggregator without being sent directly to the cloud computing center, and the transaction message report is verified by the edge server. Therefore, the load of the cloud computing center can be reduced and the computing overhead can be reduced.

[0182] Step S500: Send a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center can collaboratively authenticate the registration message of the electric vehicle and obtain a transaction token.

[0183] Specifically, the edge server sends a collaborative authentication request request es Go to the cloud computing center and enter the edge server's private key α es =h(sk es ), and generate a random number n5∈Z p , get the message m5 from the edge server as follows:

[0184]

[0185] request es =request e ' s ⊕h(sk es )

[0186] vm5=h(ID es ‖n5‖sk es ‖T5)

[0187] Among them, SK represents the session key between the edge server and the cloud computing center, request es Indicates that the electric vehicle sends a request to the edge server to join the V2G network. e ' srepresents the request after XOR encryption, T5 represents the timestamp of message m5, and message m5 is m5:{ID es ,n5,vm5,T5}, vm5 represents the hash value of the verification message m5, ID es Indicates the real identity message of the edge server;

[0188] The message m5 is sent to the cloud computing center through the edge server, and a random number n6∈Z is generated p , get message m6:

[0189]

[0190] vm6=h(ID cc ‖n6‖T6)

[0191] Among them, SK represents the session key between the edge server and the cloud computing center, T6 represents the timestamp of message m6, and message m6 is m6:{m5,n6,vm6,T6}, vm6 represents the hash value of the verification message m6, and ID cc A real identity message indicating a cloud computing center;

[0192] The registration message of the electric vehicle is checked through the cloud computing center. For the electric vehicle with the registration message, the cloud computing center sends the transaction token Token and the message m6:{m5,n6,vm6,T6} to the electric vehicle.

[0193] The cloud computing center processes n message vectors at a time Signature, cloud computing center selection and The process is as follows:

[0194]

[0195] Among them, the private key sk is (x,y1,...,y n ), the public key pk is The cloud computing center signs the message and selects The process is as follows:

[0196]

[0197] in,

[0198] To verify the message from the cloud computing center, the electric vehicle first resolves σ to (σ1,σ2) and then verifies and

[0199] The electric vehicle parses σ to obtain the signature sent by the cloud computing center, which selects and in, The process is as follows:

[0200]

[0201] Set private key sk←X, public key

[0202] The electric vehicle obtains the message vector (m1,...,m n ) first selects a random number The process is as follows:

[0203]

[0204] The electric car sends C to the cloud computing center, and both the cloud computing center and the electric car run a knowledge proof of open commitment. If the cloud computing center is convinced, the cloud computing center selects a random number and returns The process is as follows:

[0205]

[0206] The signature σ satisfies and

[0207] After the electric vehicle parses the signature σ, it needs to make sure that the signature σ is authenticated by the cloud computing center, and the electric vehicle needs to maintain anonymity. is the public key and σ=(σ1,σ2) is the message vector (m1,...,m n )’s valid signature.

[0208] To prove the content of the signature σ, the verifier performs the following operations:

[0209] The signature σ first selects a random number The process is as follows:

[0210]

[0211] The signature σ sends σ′=(σ1′,σ2′) to the verifier and the message vector (m1,...,m n )’s knowledge π and t1 are used for zero-knowledge interactive proof, and the process is as follows:

[0212]

[0213] If π is valid, the verifier accepts the signature σ.

[0214] For electric vehicles that are not registered in the cloud computing center, the cloud computing center marks it as a malicious electric vehicle, tracks the identity of the electric vehicle with the edge server, and then disconnects from the electric vehicle.

[0215] In this embodiment, malicious electric vehicles can be prevented from participating in electricity trading through collaborative authentication between the edge server and the cloud computing center.

[0216] Step S600: Based on the transaction token, the electric vehicle and the charging station authenticate each other and complete the transaction, and the pseudonym of the electric vehicle is updated.

[0217] Specifically, after the electric car receives the transaction token sent by the cloud computing center, it needs to authenticate with the charging station and complete the transaction. The process is as follows:

[0218] Input the transaction token Token through the electric car and calculate α ev =h(Token), generate a random number n7∈Z p :

[0219] sk ev =sk e ' v ⊕h(Token)

[0220] vm7=h(PID ev ‖n7‖sk ev ‖T7)

[0221] Among them, sk ev Indicates the private key of the electric vehicle, sk e ' v represents the private key after XOR encryption, T7 represents the timestamp of message m7, and message m7 is m7:{PID ev ,n7,vm7,T7}, vm7 represents the hash value of the verification message m7, PID ev A pseudonym for an electric car;

[0222] Through the electric vehicle to send the message m7: {PID ev ,n7,vm7,T7} is sent to the charging station to generate a random number n8∈Z p :

[0223] vm8=h(ID cs ‖n8‖k ce ‖T8)

[0224] T8 represents the timestamp of message m8, and message m8 is m8:{m7,ID cs ,n8,vm8,T8}, vm8 represents the hash value of the verification message m8, ID csA message indicating the real identity of the charging station;

[0225] The charging station sends the message m8:{m7,ID cs ,n8,vm8,T8} is sent to the cloud computing center. When message m8 arrives, the cloud computing center locates the pseudonymous PID of the electric vehicle in the database of the cloud computing center. ev ;

[0226] Generate session key SK and new pseudonym through cloud computing center

[0227]

[0228] SK ev =h(ID ev ‖sk ev ‖n7)⊕SK

[0229] SK cs =h(ID cs ‖k ce ‖n8)⊕SK

[0230] vm7=h(SK cs ‖k ce ‖n9)

[0231]

[0232] Where h(·) represents the hash function, n9 represents the random number, and PID ev A pseudonym for an electric car. Indicates the updated pseudonym after XOR encryption, SK ev Represents the session key of the electric vehicle, SK cs represents the session key of the charging station, k ce Represents an identifier;

[0233] A message m9 is composed through the cloud computing center: Send message m9 to the charging station;

[0234] After the charging station receives vm7, it verifies and calculates m7 through vm7. If the verification is successful, the charging station decrypts the session key SK=h(ID cs ‖k ce ‖n8)⊕SK cs And send a message m 10 : To the electric car, after receiving vm8, the electric car verifies m8 through vm8 and calculates the session key SK = h(ID ev ‖sk ev ‖n7)⊕SK ev, so that electric vehicles and charging stations can authenticate each other and complete transactions;

[0235] After the transaction is completed, update the electric vehicle's pseudonym as follows:

[0236]

[0237] in, A pseudonym for an updated electric car, sk ev Represents the private key of the electric vehicle.

[0238] Since the private key is stored in the tamper-proof device of the electric vehicle, the malicious electric vehicle cannot calculate the updated pseudonym through the hash function without knowing the private key of the electric vehicle, and cannot continue to monitor the electric vehicle. In addition, the cloud computing center needs to keep a copy, as shown below:

[0239]

[0240] Among them, VT i ' represents the validity period of the updated pseudonym of the electric vehicle.

[0241] The electric vehicle sends a message m during the authentication process, which is consistent with the group signature of the electric vehicle When the electric car communicates with the edge server, the edge server generates a signature The cloud computing center first verifies the validity of the edge server signature and then passes it to the database item. Check the following equation To track the identity of electric vehicles.

[0242] For better explanation, this embodiment performs the following analysis:

[0243] 1. Informal Security Analysis

[0244] (1) Identity Authentication

[0245] opponent Unable to change the message In addition, the message ms ev The integrity of the message is protected by the signature. To verify the validity of the message.

[0246] (2) Identity Privacy

[0247] Real ID for electric vehicles ev Hiding in a pseudonym In, key i ∈X is a hash key. Due to the anti-collision property of the hash function, it is difficult to obtain the PID ev Calculate the IDev , after each transaction By performing pseudonym updates, the adversary cannot continuously monitor the EV transaction process. Therefore, the adversary cannot reveal the EV’s true identity.

[0248] (3) Identity traceability

[0249] The cloud computing center verifies the signature of the edge server to ensure the validity of the signature and then searches the pre-stored database items, which contain the mapping relationship between the electric vehicle pseudonym and identity. When an electric vehicle in the electric vehicle group sends a message to the edge server, a relevant signature needs to be generated. The group signature can effectively locate the group public key and group private key of the electric vehicle in the group. The cloud computing center can track the ID of the electric vehicle through the group public key and group private key. ev .

[0250] (4) Unlinkability

[0251] The electric vehicle uploads the message using its own anonymous credentials to prevent other entities from obtaining the real identity of the electric vehicle. The electric vehicle selects a random number u ev generate in, Because u ev It's random, there's no opponent Ability to sign and signature Therefore, this embodiment supports unlinkability.

[0252] (5) Resisting network attacks

[0253] This embodiment resists the following attacks:

[0254] Tampering attack: Any ev Tampering in can be achieved through To detect whether the message has been tampered with, it can be seen from the unforgeability that there is no adversary Ability to forge messages ev Therefore, this embodiment can resist tampering attacks.

[0255] Man-in-the-middle attack: In this example, the adversary It is difficult to impersonate a real entity in a V2G network because it does not have any private keys to access a specific EV. ev and secret st ev Therefore, the opponent Unable to generate a valid signature Because it requires a private key and a secret, this embodiment is not subject to man-in-the-middle attacks.

[0256] Simulation attack: According to the unforgeability property, all adversaries Generating valid signatures for real entities in V2G networks The probability of sk is negligible. To simulate any entity, you must have the private key sk of the electric car. ev and secret st ev However, no such adversary can generate such a private key and secret. In addition, since the discrete logarithm problem is difficult to solve in polynomial time, it cannot be obtained from the public key. Extract the private key sk ev On the other hand, only the data of the edge server or other trusted electric vehicles are considered valid. Therefore, this embodiment prevents simulation attacks.

[0257] Stolen Authentication Table Attack: No authentication table is created for data authentication. Entities in the network keep their own private keys. Therefore, the adversary cannot obtain any potentially useful table. Therefore, this embodiment can resist the stolen authentication table attack.

[0258] Replay attack: The entity sends a timestamp T during registration, query, and power trading. At the same time, the pseudonym of the electric vehicle contains the pseudonym validity time VT of the electric vehicle. Replay attacks can be resisted by verifying the time T and VT. Therefore, this embodiment is not susceptible to replay attacks.

[0259] Physical Attacks: In this example, we assume that all electric vehicles are tamper-resistant, so if an adversary tries to perform any physical attacks, they can be resisted by hardware. In addition, to counter physical attacks, devices with embedded tamper-resistant technology can also be used. Any attempt to tamper with the device will change the behavior of the device, making it possible to detect any tampering.

[0260] DoS attack: Even if electric car users enter incorrect fingerprints when logging into their accounts, e ' v , equation pk e ' v =pk ev It is also possible to detect and notify electric vehicle users, and only after the equation verification is passed will a request to join the V2G network be sent to the edge server. Therefore, this embodiment can resist DoS attacks.

[0261] 2. Formal Security Analysis

[0262] (1) Message Signature

[0263] Definition 1: In Lysyanskaya–Rivest–Sahai–Wolf (LRSW), is a set of bilinear groups of type 3. g and The corresponding cyclic group and For X=g x , Y = g y , This embodiment defines a query machine in, As input and randomly select a number Then output a signature σ=(r,r x+my ). Given and For an unqueried new i′, no opponent can effectively generate a new (r,r x+i′y )and

[0264] It should be noted that Lysyanskaya–Rivest–Sahai–Wolf (LRSW) is mentioned in the document Camenisch J, Lysyanskaya A Signature schemes and anonymous credentials from bilinear maps [C] / / Annual international cryptology conference. Springer, Berlin, Heidelberg, 2004: 56-72, and is not described in detail in this embodiment.

[0265] Under LRSW definition 1, the existence and unforgeability of the entity signature in this embodiment under the chosen message attack remain unchanged, and the proof process is as follows:

[0266] Let Π′ be the signature scheme in LRSW Definition 1, and Π be the scheme proposed in this embodiment. Assume is a probabilistic polynomial-time adversary, Try to use q = q (k) Make a query and break Π, q is an adversary The upper limit of the number of queries that can be made. Only Make a query. After giving m a valid signature σ=(σ1,σ2), Will not query m again, where Output a forged signature σ′ on a new message m′ if Verify(pk,m′,σ′)=1 and This example constructs an effective adversary Call And try to break Π′.

[0267] opponent The public parameter pk included in Π is as follows Public Key and access Provide to And follow these steps:

[0268] Choose a uniform i∈{1,2,...,q};

[0269] Call if Perform the jth query m j , and respond as follows:

[0270] Get a copy (m,σ1,σ2) that executes this example normally and returns (sig1,sig2); if j≠i, select a unified And return (σ1,σ2);

[0271] if Output a forged signature (σ1′,σ2′) on a new message m′ and check and m′≠m j , if correct, output (m′,σ1′,σ2′), if not, terminate.

[0272] exist middle, As a result of a subroutine call Call The results are consistent with that of Eq. and Never Query m′, then (m′,σ1′,σ2′) is a valid signature forgery.

[0273] Therefore, this example concludes If Π′ is secure, then can be ignored. Since q(k) is a polynomial, it means The same can be ignored;

[0274] Proof completed.

[0275] (2) Message Verification

[0276] π and σ are blocks (m1,...,m r ,t) in the public key A valid signature on

[0277] In order to verify the message, this embodiment constructs a simulator S;

[0278] First, simulator S generates two The random elements σ1′ and σ2′ on the matrix and calculate σ′←(σ1′,σ2′). Where r and t are random numbers;

[0279] Next, the simulator S proves the validity of π.

[0280] This embodiment considers a prover P, and the verifier's acceptance is not negligible; then this embodiment constructs an extractor ε, and the prover P outputs a valid signature σ for the message block; since π is a proof of knowledge, ε can run the extractor ε to obtain (m1,...,m r ,t) and t, the process is as follows:

[0281]

[0282] ε can be calculated as σ=(σ1,σ2)←(σ1′,σ2′·(σ1′) -t ), which is the block (m1,...,m r ,t), the verification process is as follows:

[0283]

[0284] For any prover P accepted by the verifier with a non-negligible probability, this embodiment can construct ε by interacting with the prover P to output a valid signature, so the message is valid.

[0285] 3. Experimental analysis

[0286] The performance of this embodiment was evaluated, and the computational overhead, communication overhead, and various network indicators generated by this embodiment were analyzed. The experiment used Java 14.0.1 to simulate the power trading process and evaluate the running time of the operation, and analyzed the computational overhead and communication overhead generated in the process, the delay in the network, etc. The test environment was Win10, 3.0Ghz AMD Ryzen 54600H, 16GRAM. This solution uses JPBC to simulate encryption operations, and the symmetric bilinear pairing uses the A-type elliptic curve in is a 160-bit prime number. is a 512-bit prime number; the asymmetric bilinear pairing uses a D-type elliptic curve. EdgeCloudSim is used to evaluate the system simulation of the V2G network. To prove the effectiveness of this embodiment, this embodiment unifies the symbols and definitions in the scheme, as shown in Table 1.

[0287] symbol describe Time (ms) <![CDATA[T a-bp ]]> Symmetric bilinear pairing time 14.151 <![CDATA[T a-bm ]]> Multiplication time in symmetric bilinear pairing 0.099 <![CDATA[T a-ba ]]> Symmetric bilinear addition operation time 0.126 <![CDATA[T a-exp ]]> Exponential operation time for symmetric bilinear alignment 11.924 <![CDATA[T d-bp ]]> Asymmetric bilinear pairing time 17.117 <![CDATA[T d-exp ]]> Exponential operation time for asymmetric bilinear alignment 4.647

[0288] Table 1

[0289] (1) Calculation overhead

[0290] The computational overheads incurred by the three entities of the electric vehicle, charging station, and local aggregator in this embodiment are evaluated. In addition, Our scheme in this embodiment is compared with three other schemes, namely, Yang et al. [5], Wang et al. [6], and Wang et al. [7] in the table. First, the computational overheads of these schemes are mathematically analyzed, assuming that the overheads incurred by some lightweight cryptographic operations, such as hash operations, XOR operations, and message signatures, can be ignored. Table 2 gives a mathematical comparison of the computational overheads incurred by the two schemes, where the computational overheads incurred by the three entities of the electric vehicle, charging station, and local aggregator are given respectively.

[0291] Literature plan Electric Vehicles Charging Stations / Local Aggregators total Yang et al.[5] <![CDATA[7T a-bp +11T a-bm +4T a-ba ]]> <![CDATA[11T a-bp +6T a-bm +3T a-ba ]]> <![CDATA[18T a-bp +17T a-bm +7T a-ba ]]> Wang et al.[6] <h2 style=";text-align:left;direction:ltr"><![CDATA[5T <h2 style=";text-align:left;direction:ltr"> a-bp <h2 style=";text-align:left;direction:ltr"> +5T<h2 style=";text-align:left;direction:ltr"> a-bm <h2 style=";text-align:left;direction:ltr"> +2T<h2 style=";text-align:left;direction:ltr"> a-ba <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> <![CDATA[7T a-bp +2T a-bm +1T a-ba ]]> <![CDATA[12T a-bp +7T a-bm +3T a-ba ]]> Wang et al.[7] <![CDATA[9T a-exp ]]> <![CDATA[4T a-bp +6T a-exp ]]> <![CDATA[4T a-bp +15T a-exp ]]> Our scheme <h2 style=";text-align:left;direction:ltr"><![CDATA[5T <h2 style=";text-align:left;direction:ltr"> d-bp <h2 style=";text-align:left;direction:ltr"> +9T<h2 style=";text-align:left;direction:ltr"> d-exp <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> <![CDATA[2T d-exp ]]> <![CDATA[5T d-bp +11T d-exp ]]>

[0292] Table 2

[0293] As shown in Table 2, for Yang et al. [5], the total computational overhead is 18T a-bp +17T a-bm +7T a-ba For Wang et al. [6], the total computational overhead is 12T a-bp +7T a-bm +3T a-ba For Wang et al.[7], the total computational overhead is 4T a-bp +15T a-exp The computational overhead incurred in the entity in this embodiment is 5T d-bp +11T d-exp , this embodiment has good performance in theory.

[0294] It should be noted that Yang et al.[5] is the method in the literature Z. Yang, S. Yu, W. Lou, and C. Liu, “P2: Privacy-preserving communication and precise reward architecture for V2G networks in smart grid,” IEEE Trans. Smart Grid, vol. 2, no. 4, pp. 697–706, Dec. 2011; Wang et al.[6] is the method in the literature H. Wang, B. Qin, Q. Wu, L. Xu, and J. Domingo-Fe rrer, “TPP: Traceable privacy-preserving communication and precise reward for vehicle-to-grid networks in smart grids,” IEEE Trans. Inf. Forensics Secur, vol. 10, no. 11, pp. 2340–2351, Nov. 2015; Wang et al.[7] is the method in the literature Q. Wang, M. Ou, Y. Yang and The method in Z.Duan, "Conditional Privacy-Preserving Anonymous Authentication Scheme With Forward Security in Vehicle-to-Grid Networks," IEEE Access, vol.8, pp.217592-217602, 2020, doi:10.1109 / ACCESS.2020.3040112 is not described in detail in this embodiment.

[0295] (2) Communication overhead

[0296] The symmetric bilinear pairing type uses the 160-bit type A elliptic curve y 2 =x 3 +x, so and The element size is 40 nodes (160÷8×2). The asymmetric bilinear pairing type uses a D-type elliptic curve with an order of 170-bit, so and The element size is 42.5 nodes (170÷8×2). This embodiment assumes that the timestamp, hash function and other identification string size is 5B. This embodiment considers the overhead generated by communication with electric vehicles. The communication overhead comparison of the three schemes of Yang et al. [5], Wang et al. [6], and Wang et al. [7] is shown in Table 3.

[0297] Literature plan Number of messages Communication overhead Yang et al.[5] 5n 435 Wang et al.[6] 7n 330 Wang et al.[7] n+1 345 Our scheme 7n 275

[0298] Table 3

[0299] For the scheme of Yang et al. [5], during the permit generation phase, the EV sends a message to the central aggregator and {h, t3}, the central aggregator sends messages {z, a, b, U, Y, t2} and {S1, S2, t4} to the EVs. One message is transmitted during the license verification phase. The communication overhead of the scheme Yang et al. [5] is 40×10+5×7=435 bits.

[0300] For the scheme of Wang et al. [6], during the license generation phase, the EV sends a message {ID BV ,M,t1} and {p,t3}, the central aggregator sends messages {R,R1,R1′,t2} and {V,t4} to the EV. During the license verification phase, three messages are transmitted. The communication overhead of the scheme Wang et al.[6] is 40×7+5×10=330 bits.

[0301] For the scheme of Wang et al. [7], in the authentication phase, the EV sends a message {M,T θ ,σ,cert i The local aggregator then sends the message {c1,c2,c3,c4,time,β} to the EV. The communication overhead of the scheme Wang et al. [7] is 40×8+5×5=345 bits.

[0302] In this embodiment, during the entity registration phase, the electric vehicle sends a message {PID ev ,n1,vm1,T1}; During the mutual authentication phase, the electric vehicle sends {PID ev ,n3,vm3,T3}, then the electric vehicle sends a message to the edge server During the electricity trading process, the electric vehicle sends a message {PID ev ,n7,vm7,T7}, the charging station sends a message {m7,ID cs,n8,vm8,T8}, the cloud computing center sends a message to the charging station Charging stations send messages to electric cars The communication overhead of Our scheme in this embodiment is 42.5×4+5×21=275 bits.

[0303] (3) Simulation experiment

[0304] This embodiment evaluates the system processing time, average network delay and false alarm rate in the network. The network structures of Yang et al. [5] and Wang et al. [6] are the same. The network structures of Yang et al. [5] and Wang et al. [6] are that there is an electricity market, a control center and multiple local aggregators; the network structure of Wang et al. [7] is that there is a trust center and multiple local aggregators; the network structure of Our scheme in this embodiment is that there is a cloud computing center, multiple edge servers and multiple local aggregators.

[0305] In this embodiment, the number of electric vehicles (The number of EVs) is set from 100 to 500. Figure 2 and Figure 3 It can be seen that as the number of electric vehicles increases, the system processing time and average network delay increase, and Our scheme in this embodiment is the smallest. Taking the number of electric vehicles as an example, the system processing time of Yang et al. [5] is 2.556s, the system processing time of Wang et al. [6] is 2.015s, the system processing time of Wang et al. [7] is 1.793s, and the system processing time of Our scheme in this embodiment is 1.657s; the average network delay of Yang et al. [5] is 1.639s, the average network delay of Wang et al. [6] is 1.389s, the average network delay of Wang et al. [7] is 0.339s, and the average network delay of Our scheme in this embodiment is 0.203s.

[0306] The false alarm rate reflects the ability of the classifier or model to correctly predict the purity of positive samples and reduce the prediction of negative samples as positive samples, that is, the proportion of negative samples predicted as positive samples to the total negative samples. The smaller the false alarm rate, the better the performance. The false alarm rate FPR is expressed as follows:

[0307]

[0308] Among them, the negative samples predicted as positive samples are FP, and the negative samples predicted as negative samples are TN.

[0309] This plan sets the number of electric vehicles from 100 to 500. Figure 4 It can be seen that as the number of electric vehicles increases, the false alarm rate increases. Yang et al.[5] has the highest false alarm rate, followed by Wang et al.[6] and Wang et al.[7], and our scheme has the lowest false alarm rate. Taking the number of electric vehicles as an example, the false alarm rate of Yang et al.[5] is 31.21%, the false alarm rate of Wang et al.[6] is 29.24%, and the false alarm rate of Wang et al.[7] is 20.75%. The false alarm rate of our scheme in this embodiment is only 8.585%.

[0310] Reference Figure 5 The embodiment of the present invention further provides an electric vehicle identity authentication system, the system comprising:

[0311] A registration message acquisition unit 100 is used to acquire a registration message of the electric vehicle and the edge server joining the V2G network;

[0312] A pseudonym acquisition unit 200 is used to acquire the pseudonym of the electric vehicle through the cloud computing center according to the registration message of the electric vehicle;

[0313] The aggregator selection unit 300 is used to calculate and obtain the reputation value of the local aggregator, and select a first local aggregator whose reputation value is greater than a preset value for communication;

[0314] A message verification unit 400, configured to obtain a transaction request of the electric vehicle, send a transaction message report of the electric vehicle to the edge server through the first local aggregator, and verify the transaction message report through the edge server;

[0315] The token acquisition unit 500 is used to send a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center can collaboratively authenticate the registration message of the electric vehicle and obtain a transaction token;

[0316] The pseudonym updating unit 600 is used to update the pseudonym of the electric vehicle based on the transaction token so that the electric vehicle and the charging station can authenticate each other and complete the transaction.

[0317] It should be noted that, since the electric vehicle identity authentication system in this embodiment and the above-mentioned electric vehicle identity authentication method are based on the same inventive concept, the corresponding contents in the method embodiment are also applicable to the system embodiment and will not be described in detail here.

[0318] An embodiment of the present invention further provides an electric vehicle identity authentication device, comprising: at least one control processor and a memory for communicating with the at least one control processor.

[0319] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely disposed relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0320] The non-transient software program and instructions required to implement the electric vehicle identity authentication method of the above embodiment are stored in the memory. When executed by the processor, the electric vehicle identity authentication method of the above embodiment is executed, for example, the above described Figure 1 The method comprises steps S100 to S600.

[0321] The system embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, i.e., may be located in one place, or may be distributed over multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0322] The embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions. The computer-executable instructions are executed by one or more control processors, so that the one or more control processors can execute an electric vehicle identity authentication method in the above method embodiment, for example, executing the above described Figure 1 The functions of method steps S100 to S600 in the embodiment.

[0323] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a general hardware platform. Those skilled in the art can understand that all or part of the processes in the above embodiment method can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and the program can include the process of the embodiment of the above method when executed. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0324] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. An electric vehicle identity authentication method, characterized in that: The method comprises: Obtain registration messages of electric vehicles and edge servers joining the V2G network; According to the registration information of the electric vehicle, a pseudonym of the electric vehicle is obtained through a cloud computing center; Calculate and obtain the reputation value of the local aggregator, and select a first local aggregator whose reputation value is greater than a preset value for communication; Obtaining a transaction request of the electric vehicle, sending a transaction message report of the electric vehicle to the edge server through the first local aggregator, and verifying the transaction message report through the edge server; Sending a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center can collaboratively authenticate the registration message of the electric vehicle and obtain a transaction token; specifically: Send a collaborative authentication request through the edge server es Go to the cloud computing center and enter the private key α of the edge server es =h(sk es ), and generate a random number n5∈Z p , obtain the message m5 of the edge server in the following manner: request es =request e ′ s ⊕h(sk es ) vm5=h(ID es ‖n5‖sk es ‖T5) Wherein, SK represents the session key between the edge server and the cloud computing center, request es Indicates that the electric vehicle sends a request to the edge server to join the V2G network. e ' s represents the request after XOR encryption, T5 represents the timestamp of message m5, and the message m5 is m5:{ID es ,n5,vm5,T5}, vm5 represents the hash value of verifying the message m5, ID es A real identity message representing the edge server; The message m5 is sent to the cloud computing center through the edge server, and a random number n6∈Z is generated. p : <h2 style=";text-align:left;direction:ltr">vm6 = h(ID<h2 style=";text-align:left;direction:ltr"> cc <h2 style=";text-align:left;direction:ltr"> ‖n6‖T6) Wherein, SK represents the session key between the edge server and the cloud computing center, T6 represents the timestamp of message m6, the message m6 is m6:{m5,n6,vm6,T6}, vm6 represents the hash value for verifying the message m6, ID cc A real identity message representing the cloud computing center; The registration message of the electric vehicle is checked through the cloud computing center. For the electric vehicle with the registration message, the cloud computing center sends a transaction token Token and a message m6:{m5,n6,vm6,T6} to the electric vehicle; According to the transaction token, the electric vehicle and the charging station authenticate each other and complete the transaction, and update the pseudonym of the electric vehicle; specifically: The transaction token Token is input through the electric vehicle, and α is calculated ev =h(Token), generate a random number n7∈Z p : sk ev =sk e ′ v ⊕h(Token) vm7=h(PID ev ‖n7‖sk ev ‖T7) Among them, sk ev Represents the private key of the electric vehicle, sk e ' v represents the private key after XOR encryption, T7 represents the timestamp of message m7, and the message m7 is m7:{PID ev ,n7,vm7,T7}, vm7 represents the hash value of the message m7 for verification, PID ev a pseudonym for the electric vehicle; The electric vehicle sends the message m7: {PID ev ,n7,vm7,T7} is sent to the charging station to generate a random number n8∈Z p : vm8=h(ID cs ‖n8‖k ce ‖T8) Wherein, T8 represents the timestamp of message m8, and the message m8 is m8:{m7,ID cs ,n8,vm8,T8}, vm8 represents the hash value of verifying the message m8, ID cs A message indicating the real identity of the charging station; The charging station sends the message m8:{m7,ID cs ,n8,vm8,T8} is sent to the cloud computing center. When the message m8 arrives, the cloud computing center locates the pseudonymous PID of the electric vehicle in the database of the cloud computing center. ev ; Generate a session key SK and a new pseudonym through the cloud computing center EN ev =h(ID ev ‖sk ev ‖n7)⊕SK SK cs =h(ID cs ‖k ce ‖n8)⊕SK vm7=h(SK cs ‖k ce ‖n9) Where h(·) represents the hash function, n9 represents the random number, and PID ev represents a pseudonym for the electric vehicle, Indicates the updated pseudonym after XOR encryption, SK ev Represents the EV's session key, SK cs represents the session key of the charging station, k ce Represents an identifier; A message is composed by the cloud computing center Sending the message m9 to the charging station; After receiving vm7, the charging station verifies and calculates m7 through vm7. If the verification is successful, the charging station decrypts the session key SK=h(ID cs ‖k ce ‖n8)⊕SK cs and send a message to the electric vehicle, after receiving vm8, the electric vehicle verifies m8 through vm8 and calculates the session key SK=h(ID ev ‖sk ev ‖n7)⊕SK ev , so that the electric vehicle and the charging station can authenticate each other and complete the transaction; After the transaction is completed, the pseudonym of the electric vehicle is updated as follows: in, The pseudonym for the updated electric car, sk ev Represents the private key of the electric vehicle.

2. The electric vehicle identity authentication method according to claim 1, characterized in that: The electric vehicle identity authentication method further includes: Register the electric vehicle in the V2G network and select a random number sk ev ∈Z p as the private key of the electric vehicle, and calculate as a public key of the electric vehicle; The real identity information of the electric vehicle is sent to the cloud computing center, and the cloud computing center obtains the pseudonym of the electric vehicle through the following formula: Among them, select a hash key key i ∈X,ID ev Indicates the real identity message of the electric vehicle, VT i Indicates the validity period of the electric vehicle pseudonym, Represents the hash function, PID ev represents the pseudonym of the electric vehicle, ‖ represents a connection symbol, Z p The field Z representing prime numbers p p ; The cloud computing center calculates O ev =H(PID ev ), O ev Represents the hash value and sends O ev Sending to the electric vehicle; The electric vehicle will <H[O ev ,ID ev ,sk ev ,pk ev ,PID ev ]⊕β ev ,pk ev >Stored in a tamper-resistant device, where sk ev Represents the private key of the electric vehicle, pk ev Represents the public key of the electric vehicle.

3. The electric vehicle identity authentication method according to claim 2, characterized in that: The electric vehicle identity authentication method further includes: Register the edge server in the V2G network and select a random number sk es ∈Z p As the private key of the edge server, calculate as a public key of the edge server; Sending a request to join the V2G network to the edge server through the electric vehicle; Get the fingerprint of the user corresponding to the electric car and generate a random number n1∈Z p ; According to the user's fingerprint and the random number n1∈Z p , obtain message m1 through the following formula: en ev =en e ′ v ⊕h(β ev ) vm1=h(PID ev ‖n1‖sk ev (T1) Among them, sk e ' v represents the private key after XOR encryption, h(β ev ) represents the fingerprint of the user, SK represents the session key between the electric vehicle and the edge server, Indicates that the electric vehicle sends a request to the edge server to join the V2G network, represents the request after XOR encryption, T1 represents the timestamp of message m1, and the message m1 is m1:{PID ev ,n1,vm1,T1}, vm1 represents the hash value for verifying the message m1, and ⊕ represents the XOR operator; Sending the message m1 to the edge server through the electric car, so that the edge server sends a group signature request to the cloud computing center; According to the group signature request, the group public key and the group private key are divided by the cloud computing center, and the edge server is used as a group administrator to manage all electric vehicles within the communication range of the edge server.

4. The electric vehicle identity authentication method according to claim 1, characterized in that: The step of calculating and obtaining a reputation value of a local aggregator and selecting a first local aggregator with a reputation value greater than a preset value for communication includes: The local aggregator is scored for each registered electric vehicle to obtain the first reputation value; Accumulating the first reputation value obtained by each registered electric vehicle to obtain the reputation value of the local aggregator; The reputation value of the local aggregator is compared with a preset value, and a first local aggregator whose reputation value of the local aggregator is greater than the preset value is selected for communication.

5. The electric vehicle identity authentication method according to claim 1, characterized in that: The obtaining of the transaction request of the electric vehicle, sending the transaction message report of the electric vehicle to the edge server through the first local aggregator, and verifying the transaction message report through the edge server includes: The transaction request of the electric vehicle is obtained. If the electric vehicle passes the verification of the cloud computing center, the transaction message report of the electric vehicle is obtained in the following manner: Select a random number r0∈Z p For transaction message m ev To encrypt: Among them, em ev Represents an encrypted transaction message, Select a random number u0 to randomize the signature: in, represents the signature resolution of the electric vehicle, Represents a randomized signature; Select a random number t0 and calculate the following formula: s0←u0+c ev ·st ev Where H(.) represents a hash function, e(·) represents a bilinear pairing, and st ev ∈Z p Indicates a secret; Output an encrypted transaction message em ev Group signature on Then the transaction message report of the electric vehicle is: Among them, ms ev A transaction message report indicating the electric vehicle; The transaction message report is sent to the edge server through the first local aggregator, and the transaction message report is verified in the following manner: According to the transaction message report, the edge server Verify the transaction message report and check 6. An electric vehicle identity authentication system, characterized in that: The system comprises: A registration message acquisition unit, used to acquire registration messages of electric vehicles and edge servers joining the V2G network; A pseudonym acquisition unit, used for acquiring the pseudonym of the electric vehicle through a cloud computing center according to the registration message of the electric vehicle; an aggregator selection unit, configured to calculate and obtain a reputation value of a local aggregator, and select a first local aggregator whose reputation value is greater than a preset value for communication; a message verification unit, configured to obtain a transaction request of the electric vehicle, send a transaction message report of the electric vehicle to the edge server through the first local aggregator, and verify the transaction message report through the edge server; The token acquisition unit is used to send a collaborative authentication request to the cloud computing center through the edge server, so that the cloud computing center can collaboratively authenticate the registration message of the electric vehicle and obtain a transaction token; specifically: Send a collaborative authentication request through the edge server es Go to the cloud computing center and enter the private key α of the edge server es =h(sk es ), and generate a random number n5∈Z p , obtain the message m5 of the edge server in the following manner: request es =request e ′ s ⊕h(sk es ) vm5=h(ID es ‖n5‖sk es ‖T5) Wherein, SK represents the session key between the edge server and the cloud computing center, request es Indicates that the electric vehicle sends a request to the edge server to join the V2G network. e ' s represents the request after XOR encryption, T5 represents the timestamp of message m5, and the message m5 is m5:{ID es ,n5,vm5,T5}, vm5 represents the hash value of verifying the message m5, ID es A real identity message representing the edge server; The message m5 is sent to the cloud computing center through the edge server, and a random number n6∈Z is generated. p : <h2 style=";text-align:left;direction:ltr">vm6 = h(ID<h2 style=";text-align:left;direction:ltr"> cc <h2 style=";text-align:left;direction:ltr"> ‖n6‖T6) Wherein, SK represents the session key between the edge server and the cloud computing center, T6 represents the timestamp of message m6, the message m6 is m6:{m5,n6,vm6,T6}, vm6 represents the hash value for verifying the message m6, ID cc A real identity message representing the cloud computing center; The registration message of the electric vehicle is checked through the cloud computing center. For the electric vehicle with the registration message, the cloud computing center sends a transaction token Token and a message m6:{m5,n6,vm6,T6} to the electric vehicle; A pseudonym updating unit is used to update the pseudonym of the electric vehicle based on the transaction token so that the electric vehicle and the charging station can authenticate each other and complete the transaction; specifically: The transaction token Token is input through the electric vehicle, and α is calculated ev =h(Token), generate a random number n7∈Z p : sk ev =sk e ′ v ⊕h(Token) vm7=h(PID ev ‖n7‖sk ev ‖T7) Among them, sk ev Represents the private key of the electric vehicle, sk e ' v represents the private key after XOR encryption, T7 represents the timestamp of message m7, and the message m7 is m7:{PID ev ,n7,vm7,T7}, vm7 represents the hash value of the message m7 for verification, PID ev a pseudonym for the electric vehicle; The electric vehicle sends the message m7: {PID ev ,n7,vm7,T7} is sent to the charging station to generate a random number n8∈Z p : vm8=h(ID cs ‖n8‖k ce ‖T8) Wherein, T8 represents the timestamp of message m8, and the message m8 is m8:{m7,ID cs ,n8,vm8,T8}, vm8 represents the hash value of verifying the message m8, ID cs A message indicating the real identity of the charging station; The charging station sends the message m8:{m7,ID cs ,n8,vm8,T8} is sent to the cloud computing center. When the message m8 arrives, the cloud computing center locates the pseudonymous PID of the electric vehicle in the database of the cloud computing center. ev ; Generate a session key SK and a new pseudonym through the cloud computing center EN ev =h(ID ev ‖sk ev ‖n7)⊕SK SK cs =h(ID cs ‖k ce ‖n8)⊕SK vm7=h(SK cs ‖k ce ‖n9) Where h(·) represents the hash function, n9 represents the random number, and PID ev represents a pseudonym for the electric vehicle, Indicates the updated pseudonym after XOR encryption, SK ev Represents the EV's session key, SK cs represents the session key of the charging station, k ce Represents an identifier; A message is composed by the cloud computing center Sending the message m9 to the charging station; After receiving vm7, the charging station verifies and calculates m7 through vm7. If the verification is successful, the charging station decrypts the session key SK=h(ID cs ‖k ce ‖n8)⊕SK cs and send a message to the electric vehicle, after receiving vm8, the electric vehicle verifies m8 through vm8 and calculates the session key SK=h(ID ev ‖sk ev ‖n7)⊕SK ev , so that the electric vehicle and the charging station can authenticate each other and complete the transaction; After the transaction is completed, the pseudonym of the electric vehicle is updated as follows: in, The pseudonym for the updated electric car, sk ev Represents the private key of the electric vehicle.

7. An electric vehicle identity authentication device, characterized in that: It includes at least one control processor and a memory for communicating with the at least one control processor; the memory stores instructions that can be executed by the at least one control processor, and the instructions are executed by the at least one control processor so that the at least one control processor can execute the electric vehicle identity authentication method as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the electric vehicle identity authentication method as described in any one of claims 1 to 5.

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