A conditional privacy protection authentication method based on Internet of Vehicles

Abstract

The present invention discloses a conditional privacy protection authentication method based on the Internet of Vehicles, comprising: after initializing the system parameters, registering and authenticating the vehicle and the roadside infrastructure respectively; after the registration is completed, the vehicle enters the field of the roadside infrastructure to apply for services, the roadside infrastructure authenticates the identity of the vehicle, and after the authentication is legal, a pseudonym is generated for the vehicle and stored using a cuckoo filter, and the pseudonym and authentication information are sent to the vehicle; after the vehicle receives the pseudonym, identity authentication is performed according to the authentication information of the roadside infrastructure, and the vehicle accepts the pseudonym after successful authentication. A pseudonym is generated for the vehicle based on the roadside infrastructure, and the sender signs the message with the pseudonym and private key and sends it to the receiver, and the receiver authenticates the message using the sender information. The present invention achieves lower authentication overhead and communication overhead and achieves better security and privacy, while improving pseudonym query efficiency and reducing pseudonym storage space.

Description

Technical Field

[0001] The present invention belongs to the field of Internet of Vehicles privacy protection, and in particular, relates to a conditional privacy protection authentication method based on the Internet of Vehicles. Background Art

[0002] Vehicle-to-vehicle networks (VANETs) are a key direction in intelligent transportation, facilitating communication between vehicles and between vehicles and roadside infrastructure (RSUs). Their main goal is to ensure safer and more efficient road transport by providing real-time information about traffic conditions, potential hazards, and vehicle status. As vehicles become increasingly interconnected, the importance of VANETs continues to rise, opening up avenues for innovative applications, from collision warnings to dynamic route planning. Therefore, security and privacy have been important research areas in VANETs, ​​especially with the increasing amount of information dissemination and exchange. In VANETs, ​​each vehicle transmits traffic information to neighboring vehicles every 100-300 milliseconds via a dedicated short-range communication (DSRC) protocol. The beacon information sent by the vehicles includes safety-related information such as location, speed, and driving behavior.

[0003] As a key component of intelligent transportation systems, the Conditional Privacy Preserving Authentication (CPPA) scheme plays an important role in ensuring the privacy and safety of drivers. However, existing CPPA schemes still have problems with efficiency and security, and it is still difficult to achieve a better balance between authentication and security privacy, including:

[0004] (1) Pseudonym management issues.

[0005] The pseudonym generating entities are different. If it is TA or the vehicle itself, it is easy to cause TA's single point failure problem and over-centralization; if it is generated by the vehicle itself, it will lead to potential pseudonym abuse problems.

[0006] The storage and search efficiency of pseudonyms is not high. The existing solution uses a table to store, search and delete pseudonyms. If stored, the entire pseudonym is directly stored, which takes up a lot of space and takes a long time to search and delete. This will lead to low efficiency when performing related operations on a large number of pseudonyms.

[0007] (2) Existing solutions have low security and high computational overhead

[0008] Many solutions do not verify each other's identity before communication, which cannot guarantee the security and reliability of messages;

[0009] Many schemes involve complex cryptographic operations, such as bilinear mapping operations, which results in high computational overhead.

[0010] These factors all affect the development of the Internet of Vehicles. How to reduce costs and achieve better security, privacy and efficiency is an urgent problem that needs to be solved. Summary of the invention

[0011] To solve the above problems, the present invention provides the following solution: a conditional privacy protection authentication method based on Internet of Vehicles, comprising:

[0012] After the trusted third party TA initializes the system parameters, it registers and authenticates the vehicle and roadside infrastructure respectively. After successful registration, the vehicle and roadside infrastructure obtain vehicle authentication and roadside infrastructure authentication respectively;

[0013] After registration is completed, the vehicle enters the area of ​​the roadside infrastructure to apply for services. The roadside infrastructure authenticates the identity of the vehicle, and the authentication legally generates a pseudonym for the vehicle and stores it using the cuckoo filter, and sends the pseudonym and authentication information to the vehicle;

[0014] After receiving the vehicle, the vehicle will be authenticated based on the authentication information of the roadside infrastructure. If the authentication is successful, the vehicle will accept the pseudonym;

[0015] A pseudonym is generated for the vehicle based on the roadside infrastructure. The sender signs the message with the pseudonym and private key and sends it to the receiver. The receiver uses the sender's information to authenticate the message, completing the privacy protection authentication of the Internet of Vehicles.

[0016] Preferably, the process of the trusted third party TA initializing the system parameters includes:

[0017] The trusted third party TA selects the elliptic curve E:y 2 =x 3 +ax+b(modp), where p is the exponential order of the finite field, and a,b∈F p , F p is a finite field of E;

[0018] The trusted third party TA selects an additive group G of order q, whose generator is P, and a cyclic group

[0019] Then, the trusted third party TA randomly selects a number As the system private key, and calculate the system public key P pub =sP;

[0020] Next, the trusted third party TA selects four one-time one-way hash functions, namely:

[0021]

[0022] Preferably, the process of registering and authenticating a vehicle includes:

[0023] The vehicle generates its own public-private key pair, where the private key And calculate the public key V pk =V sk P;

[0024] The vehicle will have the private key V sk The vehicle then stores its real identity V id and public key V pk Sent to a trusted third party TA through a secure channel;

[0025] After receiving the V id Check the local database for existence. If it exists, it means the vehicle has been registered, and the trusted third party TA returns a rejection response. If it does not exist, it means the vehicle is a new user, and the trusted third party TA continues the next registration operation;

[0026] The trusted third party TA generates an identity certificate V for the vehicle token , where V token =H0(V pk ||s||Vid), and then {V id , V pk , V token} is stored in the local database and the status is set to activated, indicating that the identity credential of the vehicle user is activated; afterwards, the trusted third party TA sends the public parameters Param and V token It is sent to the vehicle through a secure channel, where the public parameters are Param = {a, b, P, G, H, H0, H1, H2}.

[0027] Preferably, the process of registering and authenticating roadside infrastructure includes:

[0028] The roadside infrastructure generates its own public-private key pair, where the private key is And calculate its public key R pk =R sk P;

[0029] Roadside infrastructure will be its true identity id and public key R pk Sent to a trusted third party TA through a secure channel;

[0030] After receiving the public key and real identity of the roadside infrastructure, the trusted third party TA generates an identity certificate R based on the public key token , and then (R pk ,Rid,R token ) is stored in the local database, and then the trusted third party TA selects two random numbers s1 and s2;

[0031] Finally, the trusted third party TA sends the public parameters Param, R token and S1, S2, where R token =Sig(s,R pk );

[0032] The random seeds S1, S2 are used to generate a one-time pseudonym for a legal vehicle, R token Used for authentication with the vehicle.

[0033] Preferably, the process of generating a pseudonym for a vehicle based on the roadside infrastructure comprises:

[0034] 1) Vehicle preparation and sending request

[0035] Vehicle V sends a service request to the roadside infrastructure as {V pk ,V token ,T}, where T represents the current timestamp, V token It is an encrypted string generated by a trusted third party TA, which contains the vehicle's public key information, real identity information, and system private key;

[0036] 2) RSU receives the request and responds

[0037] The roadside infrastructure receives the requested information and performs authentication, including:

[0038] First, check the validity of T. If it is invalid, reject it. If it is valid, proceed to the next step.

[0039] Secondly, the roadside infrastructure parses the vehicle's public key and identity credentials from the request information, and then sends them to the trusted third party TA to check whether its token has been revoked. If the verification fails, the service request is rejected and an error message is sent to the vehicle. If the token verification succeeds, the roadside infrastructure will confirm that the vehicle's identity is legitimate and has the right to use the Internet of Vehicles service. Once the vehicle's identity is verified, the roadside infrastructure can provide corresponding services based on the vehicle's request and generate a pseudonym for it for subsequent communications.

[0040] 3) Roadside infrastructure generates pseudonyms and stores pseudonyms

[0041] The roadside infrastructure uses S1 and S2 to generate a corresponding one-time pseudonym for the vehicle in each time period, which is the vehicle V i Generating a one-time pseudonym involves:

[0042]

[0043] S i,j =Hj (S i,1 )

[0044]

[0045] S i,w-j+1 =H w-j+1 (S i,2 )

[0046]

[0047] Where w represents the number of time periods in a day, is a random number selected by the roadside infrastructure in time period j, j∈[1,w], H j and H w-j+1 Represent the hash values ​​at time j and w-j+1 respectively;

[0048] After generating the pseudonym, the roadside infrastructure selects a hash function hash(·) and then updates the valid pseudonym cuckoo filter cf1 through the insertion algorithm. The specific process is as follows:

[0049] The roadside infrastructure is first calculated by the formula f = Fingerprint (Pid i,j ) calculates the fingerprint of the pseudonym, and then uses the formula i1 = hash (Pid i,j ) calculates the slot of the pseudonym in cf1, and by the formula Calculate another candidate slot for the pseudonym in cf1;

[0050] If there is a free slot in the two candidate positions calculated, the system will randomly select a free slot to insert the new element; if both candidate positions calculated are full, the system will randomly select one of the candidate positions, remove the existing element at the candidate position, and then insert the pseudonymous fingerprint to be stored into the candidate position;

[0051] After completing the previous steps, the roadside infrastructure will then return a response to the vehicle, with the response content being resp = {Pid i,j ,R token ,R pk ,T2,σ i}, where σ i =sig(R sk ,m), m=Pid i,j ||R token ||R pk ||T2.

[0052] Preferably, after generating a pseudonym for the vehicle based on the roadside infrastructure, the method further comprises:

[0053] The vehicle will first verify the validity of timestamp T2. If the timestamp is invalid, the response message will be directly rejected;

[0054] The public key R of the roadside infrastructure used by the vehicle pk Signature Verification i , that is, Verify(R pk ,σ i ,m) is equal to 1. If not, the verification fails and the vehicle will reject the message. If yes, the verification succeeds and the identity credential R of the roadside infrastructure is continued. token verify;

[0055] Vehicle system public key P pub Verifying Roadside Infrastructure token , that is, Verify(R pk ,R token ,P pub ) Is it 1? If not, the verification fails and the vehicle will reject the message;

[0056] If the above equations are all true, then the roadside infrastructure and vehicle V i The mutual identity authentication of vehicle V is successful. i Receive a pseudonym to be used in future communications.

[0057] Preferably, the process in which the sender signs the message using the pseudonym and the private key and then sends the message to the receiver includes:

[0058] Vehicle V i Prepare the message m to be sent, your pseudonym Pid, ​​and your public key V pk And the current timestamp t, and then sign it with your own private key, that is, σ=Sig(V sk ,{m,Pid,V pk ,t}), finally, vehicle V i The information group {σ,m,PID i,j ,V pk ,T3} is sent to the nearby receiving vehicle.

[0059] Preferably, the process of the receiver authenticating the message using the sender information includes:

[0060] The receiver first checks the validity of the timestamp t. If it is invalid, it directly rejects the message;

[0061] The receiver checks cf1 based on the pseudonym to see if it exists. If it does not exist, it means the pseudonym is invalid and the message is rejected. If it exists, it proceeds to the next step.

[0062] If the previous verification is successful, then verify whether the signature σ is valid, that is, determine whether Verify(V pk ,m,σ) is 1. If it is 1, the verification is successful; if the verification is unsuccessful, it enters the revocation stage.

[0063] Preferably, the process of the sender having his pseudonym revoked after being found to have sent a false message includes:

[0064] When the receiver detects a malicious vehicle sending a false message, it immediately takes action to send a report to the roadside infrastructure; the report includes the receiver's public key and pseudonym, which are key data that helps track and identify the vehicle;

[0065] After receiving the report, the roadside infrastructure revokes the pseudonym of the malicious vehicle according to a predetermined security protocol and procedure. The revocation operation includes deleting the pseudonym from cf1 of the roadside infrastructure and adding it to cf2, and sending a notification to other relevant systems or agencies to ensure that the malicious vehicle cannot continue to use its original pseudonym to communicate in the network;

[0066] The specific steps are as follows: The receiving vehicle V j The sender's public key V pki 、Pid i , your own public key V pkj , fake messages fakenew and their own signatures to these messages are sent to roadside infrastructure;

[0067] Roadside infrastructure receives j After the report message is received, the V pkj Determine whether this message comes from V j If not, it is determined to be intentional interference from a malicious third party and the report is rejected; if the verification is successful, it is determined whether fakenew is false based on the current situation. If fakenew is not false, the roadside infrastructure will take corresponding punishment measures; if fakenew is indeed false, V is revoked. i Pid i ;

[0068] Roadside infrastructure first calculates Pid i The fingerprint f is then calculated for each slot, and the positions of the two slots are traversed until the fingerprint is found. Once found, the roadside infrastructure deletes the value and then replaces Pid i Inserted into the revoke pseudonym cuckoo filter cf2, so far, the pseudonym of the vehicle has been revoked;

[0069] In addition, roadside infrastructure will also i The public key Vpki Send it to him and tell him about V i To this end, TA first searches for V in the local database. pki The corresponding identity certificate V tokeni The status is set to revoked, indicating that it has been revoked.

[0070] Compared with the prior art, the present invention has the following advantages and technical effects:

[0071] The present invention utilizes a verifiable token mechanism to verify the legitimacy of the other party's identity before the two communicating parties send information, thereby ensuring the security of the information. In addition, during the entire process, the true identity of the vehicle is only known by a trusted third party TA, and no other entity can know it, thereby ensuring minimal information leakage.

[0072] By constructing a signature verification algorithm based on elliptic curve construction, the present invention can achieve lower authentication overhead and communication overhead and reduce delay compared with most schemes that introduce bilinear pairing to verify signatures.

[0073] The present invention is different from the traditional pseudonym generation entity. Through RSU generation, the pseudonyms of vehicles can be effectively and uniformly managed, avoiding the hidden danger of single point failure when generated by TA and the possible witch attack behavior of vehicle self-generation. It not only alleviates the load of TA, but also can generate pseudonyms for vehicles in real time.

[0074] The present invention constructs a double cuckoo filter data structure and applies it to the insertion, query and revocation process of pseudonyms. This has two advantages. First, unlike the traditional use of tables to store pseudonyms, the hash value of the pseudonym is calculated through the cuckoo filter and a certain amount of bits are taken. Then we only need to store this fingerprint information in the cuckoo filter. Compared with directly storing pseudonyms in a table, the storage overhead of the RSU can be greatly reduced.

[0075] The present invention optimizes the pseudonym revocation problem. For the operation of revoking a pseudonym in the existing solution, if the pseudonym of a vehicle is expired or the vehicle does something malicious, when the pseudonym needs to be revoked, the status of the pseudonym is generally set to invalid, and then the status is written into the revocation list. This time complexity can reach O(N), where N is the number of pseudonyms. The cuckoo filter has the function of deleting elements, so the cuckoo filter can be used to store the fingerprint information of the pseudonym. When performing the pseudonym revocation operation, the pseudonym is first deleted from the valid pseudonym cuckoo filter, and then added to the invalid pseudonym cuckoo filter. If other vehicles want to determine whether the pseudonym is revoked, they only need to query in the invalid pseudonym cuckoo filter. This time complexity can be reduced to O(1). BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0077] Figure 1 This is a schematic diagram of the structure of a vehicle networking model according to an embodiment of the present invention;

[0078] Figure 2 A schematic diagram of a method flow of an embodiment of the present invention;

[0079] Figure 3 A schematic diagram of vehicle registration steps according to an embodiment of the present invention;

[0080] Figure 4 A schematic diagram of RSU registration steps according to an embodiment of the present invention;

[0081] Figure 5 A schematic diagram of a pseudonym insertion step according to an embodiment of the present invention;

[0082] Figure 6 A schematic diagram of a mutual authentication process according to an embodiment of the present invention;

[0083] Figure 7 A schematic diagram of a pseudonym search process according to an embodiment of the present invention;

[0084] Figure 8 Schematic diagram of a pseudonym deletion process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0085] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0086] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0087] like Figure 1-2 As shown, a conditional privacy protection authentication method based on the Internet of Vehicles provided by the present invention can be divided into five steps, namely, a system initialization step, a vehicle and RSU registration step, a pseudonym generation step, a message signing step and a message verification step;

[0088] Among them, the system parameters are initialized through the system initialization step;

[0089] The vehicle and RSU entities are registered and authenticated respectively through the vehicle and RSU registration steps, and the vehicle certification and roadside infrastructure certification are obtained accordingly;

[0090] The pseudonym generation step is that the RSU generates a pseudonym for the successfully authenticated vehicle and stores it in the valid pseudonym cuckoo filter. After that, the RSU sends the pseudonym and its own identity authentication message to the vehicle. After the vehicle receives it, it authenticates its identity according to the authentication information of the roadside infrastructure. Only after the authentication is successful, the vehicle will accept the pseudonym.

[0091] The message signing step is that the sender signs the message with a pseudonym and private key to ensure the privacy of the vehicle;

[0092] The message authentication step is that the receiver uses the sender's information to authenticate the message.

[0093] Furthermore, in the system initialization step, the trusted third party TA selects the elliptic curve E:y 2 =x 3 +ax+b(modp), where p is the exponential order of the finite field, and a,b∈F p , F p is a finite field of E; in addition, the trusted third party TA selects an additive group G of order q, whose generator is P, and a cyclic group Then, the trusted third party TA randomly selects a number As the system private key, and calculate the system public key P pub =sP; Next, the trusted third party TA selects four one-time one-way hash functions, namely:

[0094]

[0095] Furthermore, in the registration step, it is divided into vehicle registration and RSU registration. The specific process is as follows:

[0096] Further optimization solutions, such as Figure 3 As shown, vehicle registration steps:

[0097] First, the vehicle generates its own public-private key pair, where the private key And calculate the public key V pk =V sk P;

[0098] The vehicle will have the private key V sk Store it in your own tamper-proof device (TPD), and then use your real identity V id and public key V pk Sent to a trusted third party TA through a secure channel;

[0099] After receiving the V idCheck the local database to see if it exists. If it does exist, it means that the vehicle has been registered, and the trusted third party TA returns a rejection response; if it does not exist, it means that the vehicle is a new user, and the trusted third party TA will continue with the next registration operation. The trusted third party TA will generate an identity certificate V for the vehicle token , where V token =H0(V pk ||s||Vid). Then {V id , V pk , V token} is stored in the local database and the status is set to activated, indicating that the identity credential of the vehicle user is activated. token Sent to the vehicle through a secure channel, where the public parameters are Param = {a, b, P, G, H, H0, H1, H2};

[0100] Further optimization solutions, such as Figure 4 As shown, RSU registration steps:

[0101] First, RSU generates its own public-private key pair, where the private key is And calculate its public key R pk =R sk P;

[0102] RSU will use its true identity R id and public key R pk Sent to a trusted third party TA through a secure channel;

[0103] The trusted third party TA randomly selects a number And generate R for RSU token ={A,S R};

[0104] After receiving the public key and real identity of the roadside infrastructure, the trusted third party TA generates an identity certificate R for it based on its public key. token , and then (R pk ,Rid,R token ) is stored in the local database, and then the trusted third party TA will select two random numbers s1 and s2. Finally, the trusted third party TA sends the public parameters Param and R to the roadside infrastructure through a secure channel. token And s1,s2. Among them, R token =Sig(s,R pk );

[0105] In the RSU registration step, the RSU obtains its own identity certificate R token, and two random seeds S1, S2, where the random seed is used to generate a one-time pseudonym for a legitimate vehicle, R token Used for authentication with the vehicle.

[0106] Furthermore, if Figure 5 As shown, the pseudonym generation and storage steps include:

[0107] 1) Vehicle preparation and sending request

[0108] Vehicle V sends a service request to the roadside infrastructure as {V pk ,V token ,T}, where T represents the current timestamp, this V token It is an encrypted string generated by a trusted third party TA, which contains the vehicle's public key information, real identity information, and system private key;

[0109] 2) RSU receives the request and responds

[0110] The roadside infrastructure receives the requested information and performs authentication, including:

[0111] First, check the validity of T. If it is invalid, reject it. If it is valid, proceed to the next step.

[0112] Secondly, the roadside infrastructure will parse the vehicle's public key and identity credentials from the request information, and then send them to the trusted third party TA to query whether its token has been revoked. If the verification fails, the service request will be rejected and an error message will be sent to the vehicle. If the token verification is successful, the roadside infrastructure will confirm that the vehicle's identity is legal and has the right to use the Internet of Vehicles service. Once the vehicle's identity is verified, the roadside infrastructure can provide corresponding services based on the vehicle's request and generate a pseudonym for it for subsequent communications.

[0113] 3) RSU generates and stores pseudonyms

[0114] The roadside infrastructure uses S1 and S2 to generate a corresponding one-time pseudonym for the vehicle in each time period, with the vehicle V i For example, the specific operations include:

[0115]

[0116] S i,j =H j (S i,1 )

[0117]

[0118] S i,w-j+1 =H w-j+1 (S i,2)

[0119]

[0120] Where w represents the number of time periods in a day, is the random number selected by RSU in time period j, j∈[1,w], H j and H w-j+1 Represent the hash values ​​at time j and w-j+1 respectively;

[0121] After generating the pseudonym, the RSU selects a hash function hash(·) and then updates the valid pseudonym cuckoo filter cf1 through the insertion algorithm. The specific process is as follows:

[0122] RSU first uses the formula f = Fingerprint (Pid i,j ) Calculate the fingerprint of the pseudonym.

[0123] RSU is calculated by the formula i1=hash(Pid i,j ) Calculates a slot for the pseudonym in cf1.

[0124] RSU by formula Calculate another candidate slot for the pseudonym in cf1.

[0125] If there is a free slot in the two calculated candidate positions, the system will randomly select a free slot to insert the new element. However, if both calculated candidate positions are full, the system will randomly select one of the candidate positions, remove the existing element at that position (or "kick it out"), and then insert the pseudonymous fingerprint to be stored at that position. This processing strategy ensures that new pseudonymous fingerprints can be efficiently stored and managed even when space is limited.

[0126] During the insertion process of the cuckoo filter, when a candidate position is full, the system will recalculate another candidate position for the kicked out element according to a predetermined formula. If there is an empty slot at that position, the kicked out element will be inserted into this new empty slot. If the newly calculated candidate position is also full, the system will continue to perform the kick-out operation and recalculate the candidate position until an empty slot is found or the number of relocation operations reaches 1000. If the element cannot be successfully inserted after 1000 relocation operations, you may need to consider increasing the size of the filter or adjusting the hash function to reduce conflicts. This process ensures that the cuckoo filter can store data as much as possible while controlling the number of relocation operations to maintain high performance and efficiency.

[0127] After completing the previous steps, the RSU will then return a response to the vehicle, the response content is resp = {Pid i,j,R token ,R pk ,T2,σ i}, where σ i =sig(R sk ,m), m=Pid i,j ||R token ||R pk ||T2.

[0128] 4) Vehicle Verification Response

[0129] When the vehicle receives a response, it will first verify the response information to ensure the security and reliability of the information. The specific steps are as follows:

[0130] The vehicle will first verify the validity of timestamp T2. If the timestamp is invalid, the response message will be directly rejected;

[0131] The vehicle will use the public key R of the RSU pk Signature Verification i , that is, Verify(R pk ,σ i , m) is equal to 1. If not, the verification fails and the vehicle will reject the message. If yes, the verification succeeds and the RSU identity certificate R is continued. token verify;

[0132] The vehicle will use the system public key P pub Verify RSU's R token , that is, Verify(R pk ,R token ,P pub ) Is it 1? If not, the verification fails and the vehicle will reject the message; if yes, the verification succeeds and the vehicle receives the pseudonym Pid i,j .

[0133] In the pseudonym generation and storage steps, RSU divides the time period and distributes pseudonyms for each time period, effectively managing pseudonyms, and does not need to distribute a large number of pseudonyms to vehicles at one time, which can significantly reduce the storage overhead of vehicles; secondly, RSU will maintain a double pseudonym cuckoo filter, including a valid pseudonym cuckoo filter cf1 and an invalid pseudonym cuckoo filter cf2. If the pseudonym of a vehicle expires, it will be deleted from cf1 first and then added to cf2. This can prevent the vehicle from reusing the pseudonym and avoid the vehicle from launching a witch attack; finally, when the vehicle receives the information sent by the RSU, it will also verify the identity and message of the RSU. This mutual verification can avoid deception by malicious third parties, and the introduction of timestamps can also avoid replay attacks. Mutual authentication between vehicles and RSU can be achieved through Figure 6 Indicated.

[0134] Furthermore, as shown in Table 1, the information signing step includes: vehicle V i Prepare the message m to be sent, your pseudonym Pid, ​​and your public key V pk And the current timestamp t, and then sign it with your own private key, that is, σ=Sig(V sk ,{m,Pid,V pk ,t}), finally, vehicle V i The information group {σ,m,PID i,j ,V pk ,T3} is sent to the nearby receiving vehicle.

[0135] Table 1

[0136]

[0137] In this step, the sending vehicle will send a message to the receiving party. The signature algorithm constructed by this scheme only requires one hash operation time and one point multiplication time under an elliptic curve.

[0138] Further, as shown in Table 2, the message authentication step includes: the receiver first checks the validity of the timestamp t, and if it is invalid, directly rejects the message;

[0139] The receiver checks cf1 based on the pseudonym to see if it exists. The pseudonym search operation is as follows: Figure 7 If it does not exist, it means that the pseudonym is invalid, so reject the message; if it does exist, proceed to the next step;

[0140] If the previous verification is successful, the signature σ will be verified to be valid, that is, Verify(V pk ,m,σ) is 1. If it is 1, the verification is successful; if the verification is unsuccessful, it enters the revocation stage.

[0141] In the step of verifying the message, the scheme only requires one hash operation time and one point multiplication time under the elliptic curve.

[0142] Table 2

[0143]

[0144] Furthermore, if Figure 8 As shown, the revocation steps include:

[0145] When the receiver detects that a malicious vehicle is sending a false message, it will take immediate action and send a report to the roadside infrastructure (RSU). This report includes key data such as the receiver's public key and pseudonym that helps track and identify the vehicle. Once the RSU receives this report, it will quickly revoke the pseudonym of the malicious vehicle according to the predetermined security protocols and procedures. The revocation operation usually includes deleting the pseudonym from the RSU's cf1 and adding it to cf2, as well as possibly sending notifications to other relevant systems or agencies to ensure that the malicious vehicle cannot continue to use its original pseudonym to communicate in the network. In this way, the system can respond to the behavior of malicious vehicles in a timely manner and protect the security and stability of the network. The specific steps are as follows:

[0146] Receiving vehicle V j The sender's public key V pki 、Pid i , your own public key V pkj , fake messages fakenew and its own signatures on these messages are sent to RSU.

[0147] RSU receives the j After the report message is received, the V pkj Determine whether this message comes from V j If it is not, it may be intentional interference from a malicious third party, and the report will be rejected. If the verification is successful, it will be determined whether fakenew is false based on the current situation, because there may be malicious people who deliberately frame the good receiver. If fakenew is found to be not false, RSU will take corresponding punishment measures, such as revoking V j If fakenew is found to be fake, V i Pid i .

[0148] RSU first calculates Pid i The fingerprint f is then calculated for each slot and the positions of the two slots are traversed until the fingerprint is found. Once found, the RSU deletes the value and then sets the Pid i Inserted into the pseudonym revocation cuckoo filter cf2. At this point, the pseudonym of the vehicle has been revoked. In addition, the RSU will also i The public key V pki Send it to him and tell him about V i To this end, TA first searches for V in the local database. pki The corresponding identity certificate V tokeni The status is set to revoked, indicating that it is revoked.

[0149] In terms of communication, assume that the element size in the cyclic additive group G1 in the bilinear map is 128 bytes, and the element size in the cyclic additive group G in the elliptic curve is 40 bytes. The size of is 20 bytes. In addition, it is assumed that the size of the hash function is 20 bytes, the size of the timestamp is 4 bytes, the size of the pseudonym is 20 bytes, and the size of the message m is 20 bytes. In the vehicle communication of this embodiment, the information tuple {e=(Y,U),m,PID i,j ,V pk ,T3} to the receiving vehicle, where Therefore, the total overhead is 20×2+40×1+4×1+20×1+20=124 bytes.

[0150] The meanings of the symbols in this embodiment are shown in Table 3.

[0151] Table 3

[0152]

[0153]

[0154] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A conditional privacy protection authentication method based on Internet of Vehicles, It is characterized in that include: After the trusted third party TA initializes the system parameters, it registers and authenticates the vehicle and roadside infrastructure respectively. After successful registration, the vehicle and roadside infrastructure obtain vehicle authentication and roadside infrastructure authentication respectively; After registration is completed, the vehicle enters the area of ​​the roadside infrastructure to apply for services. The roadside infrastructure authenticates the identity of the vehicle, and the authentication legally generates a pseudonym for the vehicle and stores it using the cuckoo filter, and sends the pseudonym and authentication information to the vehicle; After receiving the vehicle, the vehicle will be authenticated based on the authentication information of the roadside infrastructure. If the authentication is successful, the vehicle will accept the pseudonym; Generate a pseudonym for the vehicle based on the roadside infrastructure. The sender signs the message with the pseudonym and private key and sends it to the receiver. The receiver uses the sender's information to authenticate the message, completing the privacy protection authentication of the Internet of Vehicles. The process of generating a pseudonym for a vehicle based on the roadside infrastructure includes, 1) Vehicle preparation and sending request Vehicle V sends a service request to the roadside infrastructure as {V pk ,V token ,T}, where V pk represents the vehicle public key, T represents the current timestamp, V token It is an encrypted string generated by a trusted third party TA, which contains the vehicle's public key information, real identity information, and system private key; 2) RSU receives the request and responds The roadside infrastructure receives the requested information and performs authentication, including: First, check the validity of T. If it is invalid, reject it. If it is valid, proceed to the next step. Secondly, the roadside infrastructure parses the vehicle's public key and identity credentials from the request information, and then sends them to the trusted third party TA to check whether its token has been revoked. If the verification fails, the service request is rejected and an error message is sent to the vehicle. If the token verification succeeds, the roadside infrastructure will confirm that the vehicle's identity is legitimate and has the right to use the Internet of Vehicles service. Once the vehicle's identity is verified, the roadside infrastructure provides corresponding services based on the vehicle's request and generates a pseudonym for it for subsequent communications. 3) Roadside infrastructure generates pseudonyms and stores pseudonyms Roadside infrastructure utilization 1 ,S 2 Generate a corresponding one-time pseudonym for the vehicle in each time period, then the vehicle V i Generating a one-time pseudonym involves: S i,j =H j (S i,1 ) S i,w-j+1 =H w-j+1 (S i,2 ) Among them, S 1 , S 2 represents two different random seeds, w represents the number of time periods in a day, is a random number selected by the roadside infrastructure in time period j, represents a cyclic group, j∈[1,w], H j and H w-j+1 Represent the hash values ​​at time j and w-j+1 respectively; After generating the pseudonym, the roadside infrastructure selects a hash function hash(·) and then updates the valid pseudonym cuckoo filter cf1 through the insertion algorithm. The specific process is as follows: The roadside infrastructure is first calculated by the formula f = Fingerprint (Pid i,j ) calculates the fingerprint of the pseudonym, and then uses the formula i 1 =hash(Pid i,j ) calculates the slot of the pseudonym in cf1, and by the formula Calculate another candidate slot for the pseudonym in cf1; If there is a free slot in the two candidate positions calculated, the system will randomly select a free slot to insert the new element; if both candidate positions calculated are full, the system will randomly select one of the candidate positions, remove the existing element at the candidate position, and then insert the pseudonymous fingerprint to be stored into the candidate position; After completing the previous steps, the roadside infrastructure will then return a response to the vehicle, with the response content being resp = {Pid i,j ,R token ,R pk ,T 2 ,σ i }, where σ i =sig(R sk ,m), m=Pid i,j ||R token ||R pk ||T 2 , m represents communication information, T 2 represents the current timestamp, σ i represents the signature of the information by the roadside infrastructure, R token represents the roadside infrastructure identity credential, R pk represents the roadside infrastructure public key, R sk Represents the roadside infrastructure private key.

2. According to claim 1, the conditional privacy protection authentication method based on the Internet of Vehicles, It is characterized in that The process of the trusted third party TA initializing the system parameters includes: The trusted third party TA selects the elliptic curve E:y 2 =x 3 +ax+b(mod p), where p is the exponential order of the finite field, and a,b∈F p , F p is a finite field of E; The trusted third party TA selects an additive group G of order q, whose generator is P, and a cyclic group Then, the trusted third party TA randomly selects a number As the system private key, and calculate the system public key P pub =sP; Next, the trusted third party TA selects four one-time one-way hash functions, namely:

3. According to claim 2, the conditional privacy protection authentication method based on the Internet of Vehicles, It is characterized in that The process of registering and certifying a vehicle includes: The vehicle generates its own public-private key pair, where the private key And calculate the public key V pk =V sk P; P represents the generator, represents a cyclic group; The vehicle will have the private key V sk The vehicle then stores its real identity V id and public key V pk Sent to a trusted third party TA through a secure channel; After receiving the V id Check the local database for existence. If it exists, it means the vehicle has been registered, and the trusted third party TA returns a rejection response. If it does not exist, it means the vehicle is a new user, and the trusted third party TA continues the next registration operation; The trusted third party TA generates an identity certificate V for the vehicle token , where V token =H 0 (V pk ||s||Vid), and then {V id , V pk , V token } is stored in the local database and the status is set to activated, indicating that the identity credential of the vehicle user is activated; afterwards, the trusted third party TA sends the public parameters Param and V token Sent to the vehicle through a secure channel, where the public parameters are Param = {a, b, P, G, H, H 0 ,H 1 ,H 2 }, H 0 represents a one-time one-way hash function, a represents the parameter value of the elliptic curve, G represents the additive group, V id Indicates the true identity of the vehicle.

4. According to claim 2, the conditional privacy protection authentication method based on the Internet of Vehicles, It is characterized in that The process of registering and certifying roadside infrastructure includes: The roadside infrastructure generates its own public-private key pair, where the private key is And calculate its public key R pk =R sk P; Roadside infrastructure will be its true identity id and public key R pk Sent to a trusted third party TA through a secure channel; After receiving the public key and real identity of the roadside infrastructure, the trusted third party TA generates an identity certificate R based on the public key token , and then (R pk ,R id ,R token ) is stored in the local database, and then the trusted third party TA selects two random numbers s 1 ,s 2 ; Finally, the trusted third party TA sends the public parameters Param, R token and the random seed S 1 ,S 2 , where R token =Sig(s,R pk ); The random seed S 1 ,S 2 Used to generate one-time pseudonyms for legitimate vehicles, R token Used for authentication with the vehicle.

5. The conditional privacy protection authentication method based on the Internet of Vehicles according to claim 1, It is characterized in that Generating a pseudonym for the vehicle based on the roadside infrastructure also includes: The vehicle will first verify the timestamp T 2 If the timestamp is invalid, the response message is rejected directly. The public key R of the roadside infrastructure used by the vehicle pk Signature Verification i , that is, Verify(R pk ,σ i ,m) is equal to 1. If not, the verification fails and the vehicle will reject the message. If yes, the verification succeeds and the identity credential R of the roadside infrastructure is continued. token verify; Vehicle system public key P pub Verifying R of Roadside Infrastructure token , that is, Verify(R pk ,R token ,P pub ) is 1, if not, the verification fails and the vehicle will reject the message; If the above equations are all true, then the roadside infrastructure and vehicle V i The mutual identity authentication of vehicle V is successful. i Receive a pseudonym to be used in future communications.

6. The conditional privacy protection authentication method based on the Internet of Vehicles according to claim 1, It is characterized in that The process in which the sender signs the message using the pseudonym and the private key and sends the message to the receiver includes: Sender vehicle V i Prepare the message m to be sent, your pseudonym Pid, ​​and your public key V pk And the current timestamp t, and then sign it with your own private key, that is, σ=Sig(V sk ,{m,Pid,V pk ,t}), finally, vehicle V i The information group {σ,m,PID i,j ,V pk ,T 3 }Sent to nearby receiving vehicles, T 3 Indicates the current timestamp.

7. The conditional privacy protection authentication method based on the Internet of Vehicles according to claim 1, It is characterized in that The process of the receiver authenticating the message using the sender information includes: The receiver first checks the validity of the timestamp t. If it is invalid, it directly rejects the message; The receiver checks cf1 based on the pseudonym to see if it exists. If it does not exist, it means the pseudonym is invalid and the message is rejected. If it exists, it proceeds to the next step. If the previous verification is successful, then verify whether the signature σ is valid, that is, determine whether Verify(V pk ,m,σ) is 1. If it is 1, the verification is successful; if the verification is unsuccessful, it enters the revocation stage.

8. The conditional privacy protection authentication method based on the Internet of Vehicles according to claim 7, Features The process of the sender's pseudonym being revoked after being found to have sent a false message includes: When the receiver detects a malicious vehicle sending a false message, it immediately takes action to send a report to the roadside infrastructure; the report includes the receiver's public key and pseudonym, which is key data that helps track and identify the vehicle; After receiving the report, the roadside infrastructure revokes the pseudonym of the malicious vehicle according to a predetermined security protocol and procedure. The revocation operation includes deleting the pseudonym from cf1 of the roadside infrastructure and adding it to cf2, and sending a notification to other relevant systems or institutions to ensure that the malicious vehicle cannot continue to use its original pseudonym to communicate in the network; cf1 represents a valid pseudonym cuckoo filter, and cf2 represents an invalid pseudonym cuckoo filter; The specific steps are as follows: The receiving vehicle V j The sender's public key V pki 、Pid i , your own public key V pkj , fake messages fakenew and their own signatures to these messages are sent to roadside infrastructure; Roadside infrastructure receives j After the report message is received, the V pkj Determine whether this message comes from V j If not, it is determined to be intentional interference from a malicious third party and the report is rejected; if the verification is successful, it is determined whether fakenew is false based on the current situation. If fakenew is not false, the roadside infrastructure will take corresponding punishment measures; if fakenew is indeed false, V is revoked. i Pid i ; Roadside infrastructure first calculates Pid i The fingerprint f is then calculated for each slot, and the positions of the two slots are traversed until the fingerprint is found. Once found, the roadside infrastructure deletes the value and then replaces Pid i Inserted into the revoke pseudonym cuckoo filter cf2, so far, the pseudonym of the vehicle has been revoked; In addition, roadside infrastructure will also i The public key V pki Send it to him and tell him about V i To this end, TA first searches for V in the local database. pki The corresponding identity certificate V tokeni The status is set to revoked, indicating that it has been revoked.

Images