CN112565375B - Certificateless signcryption algorithm suitable for VANETs - Google Patents

Abstract

The invention provides a certificateless signcryption method suitable for VANETs, which comprises the following steps: s1, obtaining vehicle network system parameter from vehicle network system by system establishing algorithm, establishing vehicle user ID_i(ii) a Generating a false identity of a vehicle user, a validity period of the false identity and a part of private keys by adopting a false identity generation algorithm and a part of private key generation algorithm; generating a vehicle user secret value by adopting a vehicle user secret key generation algorithm; the vehicle user sender generates a user message, generates a signcryption message based on the partial private key, the user public key and the secret value, and sends the signcryption message to the vehicle user receiver; and (4) obtaining the decrypted user message by verifying the equation to decrypt the encrypted ciphertext, and finally judging whether the decryption is effective. The invention is a high-efficiency safe certificateless secret algorithm, can provide confidentiality, authentication, integrity, non-repudiation and privacy protection for information transmitted between vehicle communication units, and provides safety guarantee for vehicle-mounted self-organizing network safety communication.

Description

Certificateless signcryption algorithm suitable for VANETs

Technical Field

The invention belongs to the field of network space security disciplines, and relates to an efficient and safe unlicensed bookmark encryption algorithm suitable for VANETs.

Background

The vehicle-mounted self-organizing network (VANETs) can effectively solve the problems of traffic safety, management, congestion and the like, and is the basis of future intelligent traffic. However, the security and privacy problems have seriously influenced the further development of the vehicular ad hoc network, the VANETs work in a wireless communication mode, have openness and vulnerability, are easy to attack and destroy, and the communication data in the VANETs are easy to monitor and forge by enemies. If private information (such as driver identity, license plate number and the like) of a vehicle user is acquired by a malicious third party, the life, property safety and the like of the vehicle user are possibly endangered. Therefore, the deployment and implementation of VANETs must meet the security requirements of information confidentiality, authentication, non-repudiation, user privacy and the like, and the design of an efficient and reliable security mechanism by using a cryptographic technology is one of the research hotspots of the VANETs at present.

Disclosure of Invention

The invention aims to provide a certificateless signcryption method suitable for VANETs, and provides a method for confidentiality, privacy protection and safety authentication for vehicle users. An efficient and safe non-certificate secret-marking algorithm can provide confidentiality, authentication, integrity, non-repudiation and privacy protection for information transmitted between vehicle communication units, and provides safety guarantee for vehicle-mounted network safety communication.

The invention provides a certificateless signcryption method suitable for VANETs, which comprises the following steps:

s1, inputting a safety parameter to the vehicle network system, obtaining the vehicle network system parameter from the vehicle network system by adopting the system establishing algorithm, and establishing the vehicle user ID through the vehicle network system parameter_i；

S2, based on vehicle user ID_iAdopting a false identity generation algorithm and a partial private key generation algorithm to generate the ID of the vehicle user_iGenerating false identity of the vehicle user, validity period of the false identity and part of private key;

s3, generating a vehicle user secret value by adopting a vehicle user key generation algorithm based on the false identity of the vehicle user, and obtaining vehicle user public key data;

s4, a vehicle user receiver and a vehicle user sender are constructed, the vehicle user sender generates a user message, and runs a signcryption algorithm on the user message based on the partial private key, the user public key and the secret value to generate a signcryption text and send the signcryption text to the vehicle user receiver;

and S5, receiving the signed cipher text through the vehicle user receiver, decrypting the signed cipher text through a verification equation to obtain decrypted user information, and finally judging whether decryption is effective.

Preferably, the S1 includes the following steps;

s1-1, inputting a safety parameter l to the vehicle network system, generating an elliptic curve group G with the order of q by a key generation center KGC, wherein q is a prime number with l bits, and forming a group Z by performing modular multiplication on q_q ^*＝{1,2,…,q-1}；

S1-2, generating group Z by key generation center KGC_q ^*Selecting a random number from {1,2, …, q-1}The random number is used as a master key of the vehicle-mounted network system;

s1-3, calling 6 different password hash functions through a key generation center KGC;

s1-4, generating vehicle network system parameters based on the elliptic curve group and the password hash function, and establishing the vehicle user ID based on the vehicle network system parameters and the vehicle network system master key_i。

Preferably, the S2 includes the following steps:

s2-1, the false identity generating algorithm passes the vehicle user ID_iFrom group Z_q ^*A random number γ is selected from {1,2, …, q-1}_iE {1,2, …, q-1}, and calculating data R by using elliptic curve group point multiplication operation_i＝γ_iP, P is a generator on the elliptic curve group G, and the vehicle user ID is transmitted through a safety channel_iAnd data R_iTransmitting to a key generation center KGC based on data R_iKey generation center KGC to vehicle user ID_iChecking validity for valid vehicle user ID_iGenerating a false identity and a validity period of the false identity of the vehicle user;

s2-2, generating group Z from key generation center KGC_q ^*Selecting random number from {1,2, …, q-1}, generating algorithm based on partial private key, and using the random number as vehicle user ID_iGenerating a partial private key;

s2-3, the vehicle user ID_iAnd after the false identity, the validity period of the false identity and the partial private key of the vehicle user are obtained, the false identity, the validity period of the false identity and the validity of the partial private key are verified.

Preferably, the S3 includes the following steps:

s3-1, vehicle user ID_iUsing a vehicle user key generation algorithm, from group Z_q ^*Selecting random number x from {1,2, …, q-1}_IDiE {1,2, …, q-1} as the secret value of the vehicle user;

s3-2, obtaining the public key data of the vehicle user based on the secret value of the vehicle user.

Preferably, the specific method for operating the signcryption algorithm in S4 is as follows:

s4-1, the vehicle user sender generates a time stamp, and the time stamp is selected from the group Z_q ^*Selecting a random number from {1,2, …, q-1}, and encrypting a user message based on the partial private key, the vehicle user public key data and the secret value to obtain a ciphertext;

s4-2, calculating a hash value based on the hash function;

s4-3, calculating a signcryption ciphertext of the user message based on the ciphertext, the hash value and the random number;

and S4-4, sending the signcryption ciphertext and the timestamp to a vehicle user receiver.

Preferably, the S5 includes the following steps:

s5-1, after the vehicle user receiver receives the signcryption text, firstly checking the validity of the timestamp, if the validity is confirmed, the vehicle user receiver decrypts the signcryption text through a signcryption-removing algorithm to obtain a decryption message;

s5-2, the vehicle user receiver checks whether the verification equation in the de-signcryption algorithm is established, if the verification equation is established, the decryption message is accepted, otherwise, the vehicle user receiver outputs a symbol of 'T', which indicates that the decryption is invalid.

The invention discloses the following technical effects:

(1) the invention avoids using expensive bilinear pairing operation and a maptoPoint hash function, and obtains higher calculation and communication efficiency;

(2) compared with the existing certificateless signcryption method, the method has more excellent safety performance because the method meets confidentiality, non-forgeability, non-repudiation and forward confidentiality and can resist short-term key leakage attack;

(3) the invention provides confidentiality, authentication, integrity, non-repudiation and privacy protection of user identity for information transmission between VANETs communication units, provides safety guarantee for rapid and healthy development of the Internet of vehicles, and lays a theoretical foundation for future intelligent traffic.

Drawings

Fig. 1 is a basic flow diagram.

Detailed Description

The technical method in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1, the invention provides a certificateless signcryption method suitable for VANETs, comprising the following steps:

s1, inputting a safety parameter to the vehicle network system, obtaining the vehicle network system parameter from the vehicle network system by adopting the system establishing algorithm, and establishing the vehicle user ID through the vehicle network system parameter_iThe VANETs represent a vehicle-mounted self-organizing network;

s1-1, inputting a safety parameter l to the vehicle network system, KGC (key generation center) generating an elliptic curve group G with the order of q (q is a prime number of one bit), wherein a generating element of G is P, and q is subjected to modular multiplication to form a group Z_q ^*＝{1,2,…,q-1}；

S1-2, KGC (key generation center) in group Z_q ^*Selecting a random number s from {1,2, …, q-1}, wherein s belongs to {1,2, …, q-1}, and taking s as a master key of the vehicle-mounted network system;

s1-3, calling 6 different password hash functions:

H₀：

l_ois a positive integer;

H₁：

H₂：

l₁is the length of the plaintext blockDegree;

H₃：

H₄：

H₅：

wherein {0,1}^*Representing a string of bits of unfixed length consisting of 0 and 1,

denotes that the length is l from 0 and 1₀A string of 0,1 bits of (c),

denotes that the length is l from 0 and 1₁A string of 0,1 bits of (c),

denotes {1,2, …, q-1}, H₁Is that

Indicates that the handle length is l₀The 0 and 1 bit strings are connected with points on three elliptic curve groups G from left to right and then are transformed into the elliptic curve groups G by a Hash algorithm

Element of (A) and (B)₂Is that

Indicates that the length formed by 0 and 1 is l₀The 0 and 1 bit strings and the points on the two elliptic curve groups G are connected from left to right and then are transformed into the elliptic curve group with the length of l by a Hash algorithm₁0,1 bit string of (2), H₃Is that

Indicates that the handle length is l₁The 0 and 1 bit strings, the points on the two elliptic curve groups G are connected from left to right and then are transformed into the elliptic curve group G by the Hash algorithm

Element of (A) and (B)₄，H₅：

Indicates that the length formed by 0 and 1 is l₀0,1 bit string, points on the three elliptic curve groups G,

Element of length l₁The 0 bit string and the 1 bit string with unfixed length are connected from left to right and then transformed into the data string by a Hash algorithm

The above elements;

s1-4, generating vehicle network system parameters based on the elliptic curve group and the password hash function, wherein the vehicle network system parameters establish the ID of the vehicle user based on the master key of the vehicle network system_i。

S2, based on vehicle user ID_iAdopting a false identity generation algorithm and a partial private key generation algorithm to generate the ID of the vehicle user_iGenerating vehicle user false identity PID_iValidity period of false identity pi_iPart of the private key d_IDi；

S2-1, based on vehicle user ID_iIn that

Up to select random number gamma_iObtaining a point R on the elliptic curve group G by using a point multiplication operation_i＝γ_iP, to send (ID) over a secure channel_i,R_i) The data are transmitted to a KGC (key generation center), and the KGC (key generation center) receives the data (ID)_i,R_i) After data, for ID_iChecking validity, if valid, calculating

Obtaining a false identity PID for the vehicle user_iIn which pi_i∈{0,1}^*A validity period representing a false identity;

s2-2, generating group Z from KGC (Key Generation center)_q ^*Selecting random number alpha from {1,2, …, q-1}_iE.g. 1,2, …, q-1, calculating the point T on the elliptic curve group G_i＝α_iP, calculating a hash value h_i＝H₁(PID_i,T_i,P,P_pub) And a value d_IDi＝sh_i+α_i(mod q) to obtain a partial private key d_IDi；

S2-3, vehicle user ID_iReceive false identity PID_iValidity period of false identity pi_iAnd part of the private key d_IDiAnd data T_iThen, the validity period pi is checked first_iThe false identity PID is judged by verifying the following two equations_iAnd part of the private key d_IDiWhether or not it is valid, or not,

d_IDiP＝h_iP_pub+T_iwherein h is_i＝H₁(PID_i,T_i,P,P_pub)；

If pi_iOr PID_iOr d_IDiIs invalid, the vehicle user ID_iRequiring KGC (key generation center) to resend data;

s3, based on vehicle user ID_iFalse identity of (2), vehicle user ID_iGenerating a secret value of a vehicle user and public key data of the vehicle user by adopting a vehicle user secret key generation algorithm;

s3-1, vehicle user ID_iUsing vehicle user secretKey generation algorithm, from group Z_q ^*Selecting random number x from {1,2, …, q-1}_IDiE {1,2, …, q-1} as the secret value of the vehicle user;

s3-2, vehicle user ID_iCalculating Q by point multiplication operation on elliptic curve_IDi＝x_IDiP, order data PK_IDi＝(Q_IDi,T_i) As vehicle user ID_iThe public key data of (a);

s4, constructing a vehicle user sender A and a vehicle user receiver B, wherein the false identity of the vehicle user sender A is PID_AThe public key is PK_A＝(Q_A,T_A) The false identity of vehicle user recipient B is PID_BThe public key is PK_B＝(Q_B,T_B) The vehicle user sender A generates a user message, runs a signcryption algorithm to generate a signcryption ciphertext based on a part of the private key, the user public key and the secret value, and then sends the signcryption ciphertext to a vehicle user receiver B;

s4-1, the vehicle user sender generates a time stamp t, and the time stamp t is selected from the group Z_qSelecting a random number from {1,2, …, q-1}, encrypting the user message by the vehicle user sender based on the timestamp t, the partial private key, the vehicle user public key data and the secret value to obtain a ciphertext, and calculating as follows: selecting a random number U epsilon {1,2, …, Q-1}, and calculating data U-U (Q)_A+T_A+h_AP_pub) Wherein the hash value h_A＝H₁(PID_A,T_A,P,P_pub)；

S4-2, calculating a hash value based on the hash function, and calculating a hash value h_B＝H₁(PID_B,T_B,P,P_pub) And the hash value K ═ H₂(PID_B,U,u(x_A+d_A)(Q_B+T_B+h_BP_pub))；

S4-3, obtaining ciphertext by utilizing XOR of hash value K and message m

Calculating the hash value phi ═ H₃(K,PID_B,PK_B) Hash value l_A＝H₄(PID_A,PK_AU, phi, c, t) and a hash value z_A＝H₅(PID_A,PK_A,U,φ,c,t)；

S4-4, calculating data

Wherein d is_APartial private key, x, representing sender A of a vehicle user_AThe secret value of the vehicle user sender A is represented, and the signcryption text sigma is finally obtained as (U, eta, c, t), and the vehicle user sender A sends the signcryption text sigma to the vehicle user receiver B as (U, eta, c, t);

s5, after the vehicle user receiver B receives the signed cipher text σ ═ U, η, c, t, the vehicle user receiver B runs the de-signed cipher algorithm to check the validity of the signed cipher text;

s5-1, after receiving a signcryption message σ ═ U, η, c, t, the receiver B first checks the validity of the time stamp t, and if valid, based on the check equation in the signcryption algorithm, uses part of the private key and the secret value (d)_B,x_B) Decrypt as follows

(1) Calculating a hash value K-H based on a hash function₂(PID_B,U,(x_B+d_B)U)；

(2) Decrypt to obtain the message

(3) Calculate 4 hash values:

φ＝H₃(K,PID_B,PK_B)，

l_A＝H₄(PID_A,PK_A,U,φ,c,t)，

z_A＝H₅(PID_A,PK_A,U,φ,c,t)，

h_A＝H₁(PID_A,T_A,P,P_pub)。

s5-2, the vehicle user receiver B checks the verification equation eta (l)_AQ_A+z_A(h_AP_pub+T_A) If U is true, if the equation is true, the message is acceptedAnd m, otherwise, rejecting signing and encrypting the character sigma, and outputting T, which indicates that the signing and encrypting are not effective.

The above-described embodiments are merely illustrative of the preferred embodiments of the present invention, and do not limit the scope of the present invention, and various modifications and improvements of the technical solutions of the present invention can be made by those skilled in the art without departing from the spirit of the present invention, and the technical solutions of the present invention are within the scope of the present invention defined by the claims.

Claims (4)

1. A certificateless signcryption method suitable for VANETs is characterized by comprising the following steps:

s1, inputting a safety parameter to the vehicle network system, obtaining the vehicle network system parameter from the vehicle network system by adopting the system establishing algorithm, and establishing the vehicle user ID through the vehicle network system parameter_i；

The S1 includes the following steps;

s1-1, inputting a safety parameter l to the vehicle network system, generating an elliptic curve group G with the order of q by a key generation center KGC, wherein q is a prime number with l bits, and forming a group Z by performing modular multiplication on q_q ^*＝{1,2,…,q-1}；

S1-2, generating group Z by key generation center KGC_q ^*Selecting a random number from {1,2, …, q-1}, and using the random number as a vehicle-mounted network system master key;

s1-3, calling 6 different password hash functions through a key generation center KGC;

s1-4, generating vehicle network system parameters based on the elliptic curve group and the password hash function, and establishing the vehicle user ID based on the vehicle network system parameters and the vehicle network system master key_i；

S2, based on vehicle user ID_iAdopting a false identity generation algorithm and a partial private key generation algorithm to generate the ID of the vehicle user_iGenerating false identity of the vehicle user, validity period of the false identity and part of private key;

the S2 includes the steps of:

s2-1, the false identity generation algorithmPassing vehicle user ID_iFrom group Z_q ^*A random number γ is selected from {1,2, …, q-1}_iE {1,2, …, q-1}, and calculating data R by using elliptic curve group point multiplication operation_i＝γ_iP, P is a generator on the elliptic curve group G, and the vehicle user ID is transmitted through a safety channel_iAnd data R_iTransmitting to a key generation center KGC based on data R_iKey generation center KGC to vehicle user ID_iChecking validity for valid vehicle user ID_iGenerating a false identity and a validity period of the false identity of the vehicle user;

s2-2, generating group Z from key generation center KGC_q ^*Selecting random number from {1,2, …, q-1}, generating algorithm based on partial private key, and using the random number as vehicle user ID_iGenerating a partial private key;

s2-3, the vehicle user ID_iAfter the false identity, the validity period of the false identity and the partial private key of the vehicle user are obtained, the false identity, the validity period of the false identity and the validity of the partial private key are verified;

s3, generating a vehicle user secret value by adopting a vehicle user key generation algorithm based on the false identity of the vehicle user, and obtaining vehicle user public key data;

s4, a vehicle user receiver and a vehicle user sender are constructed, the vehicle user sender generates a user message, and runs a signcryption algorithm on the user message based on the partial private key, the user public key and the secret value to generate a signcryption text and send the signcryption text to the vehicle user receiver;

and S5, receiving the signed cipher text through the vehicle user receiver, decrypting the signed cipher text through a verification equation to obtain decrypted user information, and finally judging whether decryption is effective.

2. The certificateless signcryption method for VANETs according to claim 1, wherein S3 comprises the steps of:

s3-1, vehicle user ID_iUsing a vehicle user key generation algorithm, from group Z_q ^*Selecting random number x from {1,2, …, q-1}_IDiE {1,2, …, q-1} as a user of the vehicleA secret value;

s3-2, obtaining the public key data of the vehicle user based on the secret value of the vehicle user.

3. The certificateless signcryption method for VANETs according to claim 1, wherein the S4 runs the signcryption algorithm as follows:

s4-1, the vehicle user sender generates a time stamp, and the time stamp is selected from the group Z_q ^*Selecting a random number from {1,2, …, q-1}, and encrypting a user message based on the partial private key, the vehicle user public key data and the secret value to obtain a ciphertext;

s4-2, calculating a hash value based on the hash function;

s4-3, calculating a signcryption ciphertext of the user message based on the ciphertext, the hash value and the random number;

and S4-4, sending the signcryption ciphertext and the timestamp to a vehicle user receiver.

4. The certificateless signcryption method for VANETs according to claim 3, wherein S5 comprises the steps of:

s5-1, after the vehicle user receiver receives the signcryption text, firstly checking the validity of the timestamp, if the validity is confirmed, the vehicle user receiver decrypts the signcryption text through a signcryption-removing algorithm to obtain a decryption message;

s5-2, the vehicle user receiver checks whether the verification equation in the de-signcryption algorithm is established, if the verification equation is established, the decryption message is accepted, otherwise, the vehicle user receiver outputs a symbol of 'T', which indicates that the decryption is invalid.

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