CN114866294B - Cloud-supervised online ride-hailing communication method - Google Patents

Abstract

The invention discloses an online car-hailing protocol with cloud supervision. The protocol includes: an initialization stage, where the supervision cloud builds and releases relevant security parameters; and a registration stage, where drivers, passengers and service providers complete identity verification before entering the system. ; The road network embedding stage, where the service provider initializes the road network; the matching stage, where the privacy-protective matching of drivers and passengers is achieved; the charging stage, where passengers pay for the services they use. The present invention uses Paillier homomorphic encryption and road network embedding algorithm to realize online car-hailing matching with cloud supervision. The service provider in the agreement can complete the matching calculation without obtaining the information of the driver and passengers, thereby effectively protecting the driver and passengers. Passenger privacy and security.

Description

Cloud-supervised online ride-hailing communication method

Technical field

The invention relates to the field of intelligent transportation, and in particular to an online car-hailing protocol with cloud supervision.

Background technique

As an emerging mode of travel, online car-hailing applications provide convenience for people's work and life. However, in the current numerous online ride-hailing applications, service providers have mastered a large amount of user information, including the identity information of drivers and passengers as well as passengers’ travel route information, etc., which poses a huge threat to users’ privacy and security. Therefore, it is necessary to design an online ride-hailing protocol with cloud supervision by the supervisor, so that information storage and matching calculation are separated. The trusted supervisor saves the user's identity information, and the service provider is only responsible for the matching calculation. In addition, it is also necessary to enhance the privacy during the matching process of drivers and passengers and protect passengers’ travel data.

Contents of the invention

The purpose of the present invention is to provide an online ride-hailing protocol with cloud supervision, which while meeting people's travel needs, protects the identity information of drivers and passengers as well as the passengers' travel data, and achieves privacy protection for drivers and passengers.

In the system designed by the present invention, the supervision cloud is responsible for the security of the system and the storage of user information, and the matching calculation of drivers and passengers is undertaken by the service provider.

After the supervision cloud completes the system initialization settings, service providers, drivers and passengers need to register with their real identities at the supervision cloud to obtain a public and private key pair. In addition, the supervision cloud will also negotiate a symmetric key with passengers for encrypted communication. content, after which the road network embedding settings are performed by the service provider. In the early stage of matching, the driver needs to periodically query his position coordinates and calculate his own high-dimensional distance vector, then encrypt the calculated vector and send it to the service provider together with his area information, and the service provider saves this information. .

When passengers need to take a ride, they first need to calculate and encrypt a high-dimensional distance vector based on their pick-up and drop-off locations, and send the area information together to the service provider. After receiving the passenger's request, the service provider matches the vehicle according to the area, and then conducts homomorphic calculations between each driver's high-dimensional distance vector and the high-dimensional distance vector of the passenger's boarding location. After the calculation is completed, the result is sent to the supervision cloud. Decrypt. The regulatory cloud obtains the appropriate vehicle from the decryption result and returns the information to the passenger through the service provider for confirmation. After the passenger confirms, the selected vehicle is returned, along with the pick-up and drop-off location encrypted using a key negotiated with the driver. The service provider sends the encrypted pick-up and drop-off location to the corresponding driver based on the confirmation information. The driver decrypts the passenger's pick-up and drop-off location and calculates a high-dimensional distance vector based on it. After the passenger gets on the bus, the driver will compare the calculated high-dimensional distance vector with the passenger. The notified verification code is sent to the service provider. The service provider performs homomorphic calculation and then sends the result to the supervision cloud. The supervision cloud verifies and charges the passenger. At this point, the online ride-hailing service process is completed.

The purpose of the present invention is achieved by providing a creative charging phase in the agreement, which charging phase includes the following steps:

(1) Supervise cloud operation Decrypt and unpack the result, and then according to /> Choose the right driver;

(2) The supervision cloud obtains the corresponding information of the selected driver based on the pseudonym, then selects a verification code for the passenger, and encrypts the information using the key negotiated with the passenger, [info _d , code] _sym = E _sym ((info _d ,code),k _r ), then {AID _d ,AID _r ,[info _d ,code] _sym } is sent to the service provider, and then the service provider sends {AID _d ,A _d ,[info _d ,code] _sym } is sent to the passenger client for confirmation;

(3) After the passenger client decrypts the information for the passenger by running D _sym ([info _d ,code] _sym ,k _r ), if the passenger confirms the ride, the passenger client will evaluate the passenger's itinerary and get on and off the passenger. The information and estimated price are encrypted separately, [l _r ] _sym =E _sym ((l _r ),H ₄ (b _r A _d )) (where Randomly generated by the passenger client, and then calculated B _r = b _r P), E _pa (cost _r ,pk _pa ), and finally the passenger client pair m' _r = {AID _r ,AID _d ,[l _r ] _sym , [cost _r ],B _r } to sign and send {m' _r ,φ _r ',t' _r } to the service provider;

(4) The service provider saves [cost _r ] and sends {[l _r ] _sym ,B _r } to the driver client corresponding to AID _d . The driver client runs (l _r )=D _sym ([l _r ] _sym , a _d B _r ) decrypts the passenger’s boarding and alighting information for the driver, and then calculates the encrypted high-dimensional distance vector of the passenger’s boarding and alighting location respectively. Then the driver client estimates the price based on the passenger's itinerary and encrypts the estimated price [cost' _r ]=E _pa (cost' _r ,pk _pa ), and the driver client sends/> To service providers and/> Homomorphic calculations are performed and submitted to the supervision cloud to verify whether the pick-up and drop-off locations of both parties correspond and whether the valuation exceeds the error. If the location is wrong or the valuation exceeds the error, both parties are notified to cancel the order; the driver waits for the passenger to get on the bus and informs the verification code, and then passes the driver customer End-encrypted code, [code']=E _pa (code',pk _pa ), sign m' _d ={AID _d ,[code']}, and then send the message {m' _d ,φ' _d ,t ' _d } to the service provider, which forwards it to the supervision cloud;

(5) Supervise cloud decryption [code'] and determine whether it is equal to the stored [code]. When the passenger arrives at the destination, the driver again calculates the encrypted high-dimensional distance vector based on the coordinates of the current passenger's drop-off location. And sent to the service provider, the encrypted high-dimensional distance vector of the drop-off location coordinates sent when matching the passenger/> Homomorphic calculations are performed, and then the service provider submits the calculation results to the regulatory cloud for decryption and verification. If passed, the passenger will be charged.

The present invention also provides a preferred registration stage, the steps of which are as follows:

(1) Service provider registration:

The service provider sends the real identity information RID _sp to the supervision cloud, the supervision cloud stores the information and runs PartialKeyGen(params,s,RID _i )→(AID _i ,T _i ,D _i ) to generate the pseudonym AID _sp for the service provider, the pseudonym The validity period T _sp and part of the public and private keys D _sp = (d _sp , R _sp ); then the supervision cloud sends (AID _sp , T _sp , D _sp ) to the service provider through a secure channel, and the service provider then runs UserKeyGen(params, D _i ,AID _i )→(sk _i ,pk _i ) generates a complete public-private key pair (pk _sp ,sk _sp ).

(2) Driver registration:

The driver sends the real identity information and vehicle information info _d to the supervision cloud, thereby obtaining the pseudonym and part of the public and private keys generated by the supervision cloud for the driver. The driver generates a complete public and private key pair after receiving (AID _d , T _d , D _d ) (pk _d ,sk _d ).

(3) Passenger registration:

The passenger sends the real identity information and vehicle information info _r to the supervision cloud, thereby obtaining the pseudonym, partial public and private key and symmetric encryption key k _r generated by the supervision cloud for the passenger. The supervision cloud will (AID _r ,T _r ,D _r , k _r ) is sent to the passenger, and the passenger generates a complete public-private key pair (pk _r ,sk _r ).

Description of the drawings

Figure 1 is a schematic diagram of the system model of the present invention;

Figure 2 is a system initialization flow chart of the present invention;

Figure 3 is a flow chart of driver and passenger matching in the present invention;

Figure 4 is a flow chart of passenger payment in the present invention.

Detailed ways

The implementation process of the present invention will be described in further detail below.

1. Function description:

This section will describe the functional functions used in the system. These functions are mainly divided into four aspects: Paillier encryption, signature verification (ECC), road network embedding and matching calculation.

1.Paillier encryption:

(1)KeyGen _pa (1 ^λ )→(pk,sk):

Function description: Enter security parameters and run the function to generate a public-private key pair.

Formal parameter description:

1 ^λ security parameters.

Return value description:

pk public key. sk private key.

Algorithm Description:

(a) Select two prime numbers p and q, and calculate N=p×q, λ=lcm(p-1,q-1).

(b) Random selection It satisfies gcd(L(g ^λ modN ² ),N)=1, where L(x)=(x-1)/N.

(c) Generate public key pk = (N, g) and private key sk = λ.

(2)E _pa (m,pk)→c:

Function description: Input plaintext and public key, run the function and return ciphertext.

Formal parameter description:

m Message clear text. pk slightly

Return value description:

c Encrypted ciphertext.

Algorithm Description:

a) Assume m∈Z _N , choose randomly

b) Calculate the ciphertext

(3)D _pa (c,sk)→m:

Function description:

Enter the ciphertext and private key, and run the function to return the decrypted plaintext.

Formal parameter description:

c slightly sk slightly

Return value description:

m slightly

Algorithm Description:

calculate

2. Signature verification (ECC):

(1)MasterKeyGen(1 ^λ )→(params,s):

Function description:

Enter the security parameters, run the function to perform secure initialization settings on the system, and the function returns the public parameters and the system master private key.

Formal parameter description:

1 ^λ security parameters.

Return value description:

(2)PartialKeyGen(params,s,RID _i )→(AID _i ,T _i ,D _i ):

Function description:

Enter the public parameters, the system master key, and the real identity of the driver or passenger, and run the function to return the pseudonym, the validity period of the pseudonym, and a partial private key.

Formal parameter description:

params slightly the s slightly RID _i The real identity information of the driver or passenger.

Return value description:

(3)UserKeyGen(params,D _i ,AID _i )→(sk _i ,pk _i ):

Function description:

Enter the public parameters, partial private key, and pseudonym, and run the function to return the complete public-private key pair.

Formal parameter description:

params slightly _i slightly _AIDi slightly

Return value description:

(4)Sign(params,sk _i ,m _i ||t _i )→(φ _i ):

Function description:

Enter the public parameters, private key, message to send, and timestamp, then run the function to return a signature for the message.

Formal parameter description:

params slightly _i slightly m _i ||t _i The message that needs to be sent and the timestamp.

Return value description:

φ _i Signature of the message. φ _i =(Y _i ,wi ₎ .

Algorithm Description:

(a) Random selection And calculate Y _i =y _i P.

(b) Calculate u _i =H ₂ (m _i ,AID _i ,pk _i ,t _i ,Y _i ) and h _3i =H ₃ (mi ,AID _i ,pk _{i ,} t _i ).

(c) Then calculate w _i =[u _i y _i +h _3i ( _xi +d _i )]modq.

(d) Finally output φ _i =(Y _i ,wi ₎ as the signature of the message and timestamp.

(5)Verify(φ _i ,m _i ||t _i ,pk _i ,AID _i )→(true or false):

Function description:

Enter the received message and run the function to verify the validity of the signature.

Formal parameter description:

_φi slightly m _i ||t _i slightly _i slightly _AIDi slightly

Return value description:

Algorithm Description:

(a) Calculate h _1i =H ₁ (AID _i ,R _i ,P _pub ), u _i =H ₂ ( _mi ,AID _i ,pk _i ,t _i ,Y _i ) and h _3i =H ₃ (m _i ,AID _i ,pk _i ,t _i ).

(b) Determine whether w _i Pu _i Y _i =h _3i (X _i +R _i +h _1i P _pub ) is established.

3. Road network embedding:

(1)GenDimensionalSet(n,V,E)→(R):

Function description:

Input the intersection and road end set V, the size of V n and the road segment set E, and run the function to return the high-dimensional embedding network space.

Formal parameter description:

no The size of the set V. V A collection of intersections and road segments. E A collection of road segments connecting two intersections (ends) in V.

Return value description:

(2)GenEembedRoadNet(V,R)→(S):

Function description:

Input the intersection (end) set and the high-dimensional embedding network space, and run the function to return the high-dimensional distance vector of each intersection (end) in the set V.

Formal parameter description:

V slightly R slightly

Return value description:

S The high-dimensional distance vector of each intersection (end) in the set V.

Algorithm Description:

(a) For v∈V, V _i,j ∈R, the shortest distance from v to V _i,j is defined as

(b)s _v ∈S, s _v =<dist _R (v,V _1,1 ),...,dist _R (v,V _i,j ),...,dist _R (v,V _{α, β} )>, S={s _v |v∈V}.

4. Match calculation:

(1)GenEncryptedsl(l,S,pk)→([s _l ]):

Formal parameter description:

l Position coordinates. S slightly pk The public key used for encryption.

Return value description:

[s _l ] Encrypted s _l .

Algorithm Description:

(a) Enter a position coordinate l. If l∈V, then s _l =s _v (l=v); if If l belongs to a point on the road segment (v _s , v _d )∈E, then calculate s _l .

s _l =<...,dist _R (l,V _i,j )=min{dist _R (l,v _s )+dist _R (v _s ,V _i,j ),dist _R (l,v _d )

+dist _R (v _d ,V _i,j )},...>.

(b) Encrypt s _l as [s _l ], [s _l ] = E _pa (dist _R (l, V _{i, j} ), pk).

(2)

Function description:

Inputting the encryption s _l of multiple drivers and a passenger, and the number of bits occupied by the distance value, the function will calculate and return a set of distance vectors between each driver and passenger based on the homomorphism of the Paillier encryption system.

Formal parameter description:

Return value description:

Algorithm Description:

where 2 ^μ makes the distance calculation value positive.

(3)

Function description:

Input the distance vector set, the bit length of the system parameter N and the number of bits occupied by the distance value, and run the function to return the packed ciphertext.

Formal parameter description:

Return value description:

Algorithm Description:

(a) Calculate the number of ciphertexts that can be packed in a slot ρ = NBitLen/μ.

(b)from Select τ (0≤τ≤ρ) ciphertexts and package them as follows:

(c) The function finally outputs the packaged result

(4)

Function description:

Inputting a packed ciphertext set and the number of packed ciphertexts in a slot, running the function returns the plaintext of the unpacked distance value.

Formal parameter description:

Return value description:

Algorithm Description:

(a) Decryption Get the packed distance value.

(b)Based on Unpack the distance value and obtain/>

2. Detailed process description:

This section will introduce the cloud-supervised ride-hailing protocol. According to the execution sequence of the protocol, the introduction is divided into five phases: (1) Initialization Phase (Setup Phase); (3) Registration Phase (Registration Phase); (3) ) Road Network Embedding Phase; (4) Ride Matching Phase; (5) Charge Phase.

(1)Initialization phase:

The supervision cloud runs MasterKeyGen(1 ^λ )→(params,s) to generate public parameter params and system public and private key pairs (pk _pa ,sk _pa ); then the supervision cloud selects a symmetric encryption algorithm and uses E _sym (m,k)→( c), D _sym (c,k)→(m) respectively represent the symmetric encryption and decryption process.

(2) Registration stage:

(a) Service provider registration:

The service provider sends the real identity information RID _sp to the supervision cloud, the supervision cloud stores the information and runs PartialKeyGen(params,s,RID _i )→(AID _i ,T _i ,D _i ) to generate the pseudonym AID _sp for the service provider, the pseudonym Validity period T _sp and partial public and private keys D _sp = (d _sp , R _sp ). Then the supervision cloud sends (AID _sp , T _sp , D _sp ) to the service provider through a secure channel, and the service provider then runs UserKeyGen (params, D _i , AID _i ) → (sk _i , pk _i ) to generate a complete public and private Key pair (pk _sp ,sk _sp ).

(b) Driver registration:

The driver sends the real identity information and vehicle information info _d to the supervision cloud, thereby obtaining the pseudonym and part of the public and private keys generated by the supervision cloud for the driver. The driver generates a complete public and private key pair after receiving (AID _d , T _d , D _d ) (pk _d ,sk _d ).

(c) Passenger registration:

The passenger sends the real identity information and vehicle information info _r to the supervision cloud, thereby obtaining the pseudonym, partial public and private key and symmetric encryption key k _r generated by the supervision cloud for the passenger. The supervision cloud will (AID _r ,T _r ,D _r , k _r ) is sent to the passenger, and the passenger generates a complete public-private key pair (pk _r ,sk _r ).

(3) Road network embedding stage:

The service provider converts the road network (V, E) into a distance vector set S = {s _v | v∈V}; then the service provider divides the road network (V, E) into different area sets G={z _i } _1≤i≤n , and publishes (S, G).

(4) Matching stage:

(a) The driver waiting for matching first obtains his own position coordinate l _driver , and runs GenEncryptedsl(l,S,pk)→([s _l ]) to obtain the encrypted high-dimensional distance vector of his own coordinates (Use pk _pa for encryption), and then select the area z _d ∈ G where you are currently located, and finally the driver randomly selects/> Calculate A _d = _ad P. The driver does the above periodically and builds the message/> Generate timestamp t _d , run Sign(params,sk _i ,m _i ||t _i )→(φ _i ) to sign it, and finally send {m _d ,φ _d ,t _d } to the service provider.

(b) The service provider verifies the information sent by the driver by running Verify(φ _i ,m _i ||t _i ,pk _i ,AID _i )→(true or false), and if the message is correct, the updated m _d is stored.

(c) When passengers need to take a bus, they first select their boarding and alighting locations l _r = (l _{r_up} ,l _{r_down} ), and run GenEncryptedsl(l,S,pk)→([s _l ]) to calculate the encryption of the boarding and alighting locations respectively. High dimensional distance vector Then the passenger selects the current area z _r ∈G and constructs the message/> Generate a timestamp t _r , run Sign(params,sk _i ,m _i ||t _i )→(φ _i ) to generate a signature, and finally send a ride matching request {m _r ,φ _r ,t _r } to the service provider.

(d) The service provider checks the legality of the request signature sent by the passenger. If it passes, it extracts the signature sent by the corresponding driver from the database according to z _r (z _r = z _d ). And get the number of bits μ occupied by the distance value, run Enter the encrypted distance vectors of passengers’ boarding locations and drivers Homomorphically calculate the distance vector between each driver and passenger in the area/> Finally, the service provider stores m _r and runs/> and Verify(φ _i ,m _i ||t _i ,pk _i ,AID _i )→(true or false) pair/> Sign the package and then //> Send to regulatory cloud.

(5)Charging stage:

(a) Supervise cloud operations Decrypt and unpack the result, and then according to /> Choose the right driver.

(b) The supervision cloud obtains the corresponding information of the selected driver based on the pseudonym, then selects a verification code for the passenger, and encrypts the information using the key negotiated with the passenger, [info _d , code] _sym = E _sym ((info _d ,code),k _r ), then {AID _d ,[info _d ,code] _sym } is sent to the service provider, and then the service provider sends {AID _d ,A _d ,[info _d ,code] _sym } Check with passengers.

(c) After the passenger decrypts the information through D _sym ([info _d ,code] _sym ,k _r ), if the ride is confirmed, the passenger will estimate his/her trip and encrypt his/her boarding and alighting information and estimated price, [ l _r ] _sym =E _sym ((l _r ),H ₄ (b _r A _d ))(where Randomly selected by passengers, passengers then calculate B _r = b _r P), E _pa (cost _r ,pk _pa ), and calculate m' _r = {AID _r ,AID _d ,[l _r ] _sym ,[cost _r ]} Sign and then send {m' _r ,φ _r ',t' _r } to the service provider.

(d) The service provider sends {[l _r ] _sym , B _r } to the driver, and the driver decrypts the information (l _r ) = D _sym ([l _r ] _sym , a _d B _r ), estimates the price and encrypts E _pa (cost _d ,pk _pa ), and then calculate the encrypted high-dimensional distance vector of the passenger's boarding and alighting location respectively. Send/> To service providers and/> Homomorphic calculations are performed and submitted to the supervision cloud to verify whether the pick-up and drop-off locations of both parties correspond and whether the valuation exceeds the error. If the location is wrong or the valuation exceeds the error, both parties will be notified to cancel the order. After waiting for the passenger to get on the bus and inform the verification code, the driver signs m' _d = {AID _d ,[code]} ([code] = E _pa (code, pk _pa )) and sends the message {m' _d ,φ' _d ,t' _d } to the service provider, and then the service provider sends it to the supervision cloud. The supervision cloud decrypts [code] and determines whether it is equal to the stored code. When the passenger arrives at the destination, the driver calculates the distance vector again based on the coordinates and sends it to the service provider for homomorphic calculation. If it matches, it is submitted to the supervision cloud for verification. If it passes Passengers will be charged.

Technical features and beneficial effects of the present invention:

The invention utilizes the additive homomorphism of the Paillier encryption algorithm so that the service provider cannot know the content of the calculation when performing matching calculations, thereby effectively protecting the privacy and security of drivers and passengers. In addition, the protocol also uses road network embedding technology to convert the road network into a high-dimensional space. The calculation of the shortest distance between two points in the network can be converted into simple calculations supported by existing encryption primitives.

Claims (1)

1. A cloud-supervised online car-hailing communication method, including a supervision cloud, a service provider, a client and an online car-hailing agreement, characterized in that the charging phase in the online car-hailing agreement includes the following steps: (1) The supervision cloud runs DeAndUnpacking({[s _ldistance ] _packing },sk,τ)→({s _ldistance }) to decrypt and unpack the result, and then according to Choose the right driver; (2) The supervision cloud obtains the corresponding information of the selected driver based on the pseudonym, then selects a verification code for the passenger, and encrypts the information using the key negotiated with the passenger, [info _d , code] _sym = E _sym ((info _d ,code),k _r ), then {AID _d ,AID _r ,[info _d ,code] _sym } is sent to the service provider, and then the service provider sends {AID _d ,A _d ,[info _d ,code] _sym } is sent to the passenger client for confirmation; (3) After the passenger client decrypts the information for the passenger by running D _sym ([info _d ,code] _sym ,k _r ), if the passenger confirms the ride, the passenger client will evaluate the passenger's itinerary and get on and off the passenger. The information and estimated price are encrypted separately, [l _r ] _sym =E _sym ((l _r ),H ₄ (b _r A _d )) (where Randomly generated by the passenger client, and then calculated B _r = b _r P), E _pa (cost _r ,pk _pa ), and finally the passenger client pair m' _r = {AID _r ,AID _d ,[l _r ] _sym , [cost _r ],B _r } to sign and send {m' _r ,φ' _r ,t' _r } to the service provider; (4) The service provider saves [cost _r ] and sends {[l _r ] _sym ,B _r } to the driver client corresponding to AID _d . The driver client runs (l _r )=D _sym ([l _r ] _sym , a _d B _r ) decrypts the passenger’s boarding and alighting information for the driver, and then calculates the encrypted high-dimensional distance vector of the passenger’s boarding and alighting location respectively. Then the driver client estimates the price based on the passenger's itinerary and encrypts the estimated price [cost' _r ]=E _pa (cost' _r ,pk _pa ), and the driver client sends/> To service providers and/> Homomorphic calculations are performed and submitted to the supervision cloud to verify whether the pick-up and drop-off locations of both parties correspond and whether the valuation exceeds the error. If the location is wrong or the valuation exceeds the error, both parties are notified to cancel the order; the driver waits for the passenger to get on the bus and informs the verification code, and then passes the driver customer End-encrypted code, [code']=E _pa (code',pk _pa ), sign m' _d ={AID _d ,[code']}, and then send the message {m' _d ,φ' _d ,t ' _d } to the service provider, which forwards it to the supervision cloud; (5) The supervision cloud decrypts [code'] and determines whether it is equal to the stored [code]; when the passenger arrives at the destination, the driver again calculates the encrypted high-dimensional distance vector based on the coordinates of the current passenger's drop-off location. And sent to the service provider, the encrypted high-dimensional distance vector of the drop-off location coordinates sent when matching the passenger/> Perform homomorphic calculations, and then the service provider will submit the calculation results to the regulatory cloud for decryption and verification. If passed, the passenger will be charged; The registration phase in the online ride-hailing agreement includes the following steps: (1) Service provider registration: The service provider sends the real identity information RID _sp to the supervision cloud, the supervision cloud stores the information and runs PartialKeyGen(params,s,RID _i )→(AID _i ,T _i ,D _i ) to generate the pseudonym AID _sp for the service provider, the pseudonym The validity period T _sp and part of the public and private keys D _sp = (d _sp , R _sp ); then the supervision cloud sends (AID _sp , T _sp , D _sp ) to the service provider through a secure channel, and the service provider then runs UserKeyGen(params, D _i ,AID _i )→(sk _i ,pk _i ) generate a complete public-private key pair (pk _sp ,sk _sp ); (2) Driver registration: The driver sends the real identity information and vehicle information info _d to the supervision cloud, thereby obtaining the pseudonym and part of the public and private keys generated by the supervision cloud for the driver. The driver generates a complete public and private key pair after receiving (AID _d , T _d , D _d ) (pk _d ,sk _d ); (3) Passenger registration: The passenger sends the real identity information and vehicle information info _r to the supervision cloud, thereby obtaining the pseudonym, partial public and private key and symmetric encryption key k _r generated by the supervision cloud for the passenger. The supervision cloud will (AID _r ,T _r ,D _r , k _r ) is sent to the passenger, and the passenger generates a complete public-private key pair (pk _r ,sk _r ).