Method and system for protecting vehicle privacy data based on collective signature

Abstract

The present invention relates to the technical field of vehicle data protection, and discloses a method and system for protecting vehicle privacy data based on collective signature. It is used when the management center and each node in the same collective communicate; the node includes a vehicle application node and a vehicle node, the vehicle application node collects the vehicle status information of the vehicle node, and the vehicle application node and the vehicle node request and receive messages; the management center is used to generate and maintain the collective public key and public private key. By constructing a collective public key and a public private key for a collective, when the vehicle application node and the vehicle node communicate, any node uses its own private key and public public key to perform a signing operation and send a signed message, and another node in the collective can only use the public public key without any information related to the signer to verify the signature, which fully protects the privacy data of the node while ensuring the credibility of the source of the message and the integrity of the information.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle data protection, and in particular to a method and system for protecting vehicle privacy data based on collective signatures. Background Art

[0002] With the development of intelligent connected cars, the proportion of vehicle software has increased significantly. In order to meet the various needs of users, car companies often have many departments responsible for the development of vehicle-side services and distribute services through remote upgrades. At the same time, car companies require vehicles to report vehicle-side status information in real time in order to detect vehicle failures in a timely manner. These vehicle-cloud communication scenarios involve a large amount of data interaction, and effective measures need to be taken to ensure vehicle communication security and data security.

[0003] In order to ensure communication security and data security during vehicle-cloud communication, certificates are used to sign the transmitted data, and the identity of the sender of the data and the accuracy of the data content are ensured through the signature verification process. However, the certificate used for signing is bound to the vehicle information. When the vehicle uses the certificate to communicate with many cloud services, each cloud service will obtain and store the vehicle's certificate information, increasing the risk of vehicle information leakage.

[0004] At the same time, when the vehicle uses the certificate to regularly send its location, status and other information that needs to be reported to the data collection platform, the data collection platform can use the vehicle's certificate and the reported vehicle-side information to draw the vehicle's operating trajectory, which makes the vehicle's itinerary at risk of being leaked.

[0005] Therefore, there is an urgent need for a method to protect vehicle privacy data, which can ensure communication security and data security without leaking vehicle privacy data during vehicle-cloud communication. Summary of the invention

[0006] In order to solve the above technical problems, the method for protecting vehicle privacy data based on collective signature provided by the present invention is used when the management center and each node in the same collective communicate;

[0007] The nodes include a vehicle application node and a vehicle node, the vehicle application node collects vehicle status information of the vehicle node, and the vehicle application node and the vehicle node request and receive messages; the management center is used to generate and maintain the collective public key and public private key;

[0008] The method for protecting vehicle privacy data based on collective signature comprises the following steps:

[0009] Generate a public key and a public private key of the group: the management center generates a pair of public keys and private keys through a large prime number generation algorithm as the public key and public private key of the group, and discloses the public key within the group;

[0010] Node registration: When a new node is added to the collective, the new node needs to perform a node registration operation, specifically: the management center generates the corresponding node's own private key based on the node's own public key and the public private key, and the management center stores the node used to represent the node identity. , the corresponding node’s own private key and its own public key;

[0011] Node message signature: When a message is requested between a vehicle application node and a vehicle node, the node message sent must be signed. Specifically, the sending node of the node message calculates the signature value of the node message through its own private key and the public key, and sends the node message with the signature value.

[0012] Node message signature verification: Based on the public key and signature value, the receiving node of the node message performs a signature verification operation on the received node message with the signature value. After the signature verification is successful, the corresponding message processing is performed according to the node message.

[0013] Furthermore, the management center generates a pair of public keys and private keys through a large prime number generation algorithm, specifically including:

[0014] The management center generates a node ID for identification G ;

[0015] Randomly generate five different large prime numbers, namely p, q, k, u, and v;

[0016] According to the five different large prime numbers, a secret key n is obtained, and n=p×q=(2k×u+1)×(2k×v+1);

[0017] Take the large prime number k as the order of the group g;

[0018] Select integers e and c such that ec = 1 mod f (n), where f (n) = (p-1) × (q-1), and gcd (e, f (n)) = 1;

[0019] Select a hash function h;

[0020] Select integer c as the public private key d; put secret key n, integer e, group g, large prime number k, hash function h and node ID G As the public key, it is represented by (n, e, g, k, h, ID G );

[0021] Publicize the public key (n, e, g, k, h, ID) within the group G ).

[0022] Furthermore, the management center generates a corresponding node's own private key based on the node's own public key and the public private key, and the management center stores the node key used to represent the node identity. And the corresponding node's own public and private keys are:

[0023] Newly added nodes generate nodes for identity identification ;

[0024] Randomly generate a random number less than k , according to the The public key of the newly added node is calculated with the group g , the calculation formula is:

[0025] ;

[0026] The management center uses the node ID of the management center G , your own public key And the public private key generates the private key of the newly added node , the formula is as follows:

[0027] ;

[0028] As mentioned As the node's own private key;

[0029] Management center storage node , the node's corresponding private key and public key, generating the node And the correspondence table between its own public and private keys.

[0030] Furthermore, the sending node of the node message calculates the signature value of the node message by using its own private key and the public key, including:

[0031] The sending node of the node message randomly generates two random numbers k1 and k2 that are less than k;

[0032] The signature value of the node message is calculated based on k1, k2, the private key and the public key. The formula is as follows:

[0033] ;

[0034] ;

[0035] ;

[0036] ;

[0037] V represents a temporary parameter, r, s1, s2 are signature value 1, signature value 2, and signature value 3 respectively, and m represents a node message;

[0038] The signature value of the node message is (r, s1, s2).

[0039] Further, according to the public key and the signature value, the receiving node of the node message performs a signature verification operation on the received node message with the signature value, specifically:

[0040] The receiving node of the node message obtains the node ID of the management center G ;

[0041] The temporary parameter V is calculated based on g and n in the public key and the signature value of the node message. ` ,for:

[0042] ;

[0043] Judge r=h(V ` ,m) is true, if so, the signature verification is successful, and the receiving node of the node message performs corresponding message processing according to the node message; if not, the signature verification fails, and the receiving node of the node message does not process the node message.

[0044] Furthermore, the managed central storage node , the node's own private key and its own public key, and also stores the application download address of the newly added vehicle application node and the corresponding service vehicle node. The management center notifies the vehicle node of the corresponding service of the newly added vehicle application node of the new message of the vehicle application node.

[0045] Furthermore, the management center notifies the vehicle node corresponding to the newly added vehicle application node of the newly added vehicle application node:

[0046] The management center uses the public private key d and the hash function h to calculate the signature value s' of the new message of the vehicle application node. The calculation formula is:

[0047] s'=(h(m)) d modn;

[0048] The management center notifies the vehicle node corresponding to the newly added vehicle application node of the newly added message and signature value s'.

[0049] Furthermore, the vehicle node corresponding to the newly added vehicle application node performs a signature verification operation on the newly added message according to the hash function h in the public key, and the formula is as follows:

[0050] ;

[0051] If the above formula is established, the signature verification operation is successful, and the vehicle node corresponding to the newly added vehicle application node performs corresponding message processing on the newly added message;

[0052] If the above formula is not true, the signature verification operation fails, and the vehicle node corresponding to the newly added vehicle application node does not perform corresponding message processing on the newly added message.

[0053] Further, the receiving node of the node message performs corresponding message processing according to the node message. If the vehicle application node receives the node message sent by the vehicle node and determines that the vehicle status information in the collected node message is abnormal, the vehicle application node applies to the management center for node identification, specifically:

[0054] The vehicle application node receives the node message sent by the vehicle node and performs a node message signature verification operation;

[0055] After the signature verification is successful, the node message sent by the vehicle node is parsed and identified, and the vehicle status information in the node message is determined to be abnormal information;

[0056] The vehicle application node sends the signature value corresponding to the abnormal information to the management center, and the management center obtains its own private key corresponding to the abnormal information according to the signature value;

[0057] The management center The corresponding relationship table of its own public and private keys, combined with its own private key corresponding to the abnormal information, determines the node of the vehicle node corresponding to the abnormal information , and sent to the vehicle application node that collected the abnormal information;

[0058] The vehicle application node that collects the abnormal information is based on the node of the vehicle node corresponding to the abnormal information. , locate the specific location of the vehicle node corresponding to the abnormal information, and carry out the corresponding fault handling process.

[0059] The present application also provides a system for protecting vehicle privacy data based on collective signature, which is used to execute any of the above methods for protecting vehicle privacy data based on collective signature, and the system includes:

[0060] Collective public key and public private key generation module: The management center generates a pair of public keys and private keys through a large prime number generation algorithm as the collective public key and public private key, and makes the public key public within the collective;

[0061] Node registration module: connected to the collective public key and public private key generation module. When a new node is added to the collective, the new node needs to perform node registration operation. Specifically, the management center generates the corresponding node’s own private key based on the node’s own public key and public private key. The management center stores the node used to represent the node identity. , the corresponding node’s own private key and its own public key;

[0062] Node message signature module: connected to the node registration module. When the vehicle application node and the vehicle node make a message request, the node message sent must be signed. Specifically, the sending node of the node message calculates the signature value of the node message through its own private key and public key, and sends the node message with the signature value.

[0063] Node message signature verification module; connected to the node message signature module, based on the public key and signature value, the receiving node of the node message verifies the received node message with the signature value, and performs corresponding message processing according to the node message after the signature verification is successful.

[0064] The embodiments of the present invention have the following technical effects:

[0065] The method for protecting vehicle privacy data based on collective signature provided by the present application is used when the management center and each node in the same group communicate; the nodes include vehicle application nodes and vehicle nodes, the vehicle application nodes collect vehicle status information of the vehicle nodes, and the vehicle application nodes and vehicle nodes request and receive messages; the management center is used to generate and maintain the collective public key and public private key. By constructing a collective public key and public private key for a group, when the vehicle application node and the vehicle node communicate, any node uses its own private key and public key to sign and send a signed message, and another node in the group can only use the public key without any information related to the signer to verify the signature, while ensuring the credibility of the source of the message and the integrity of the information, the privacy data of the node is fully protected. The vehicle application node no longer needs to collect certificate information with vehicle node identity identification for message security verification, that is, the vehicle node identity information and vehicle status information are isolated. In scenarios where vehicle nodes need to regularly report vehicle location, status and other information to vehicle application nodes, while achieving vehicle node identity authentication and reported data accuracy verification, it avoids the vehicle application node from drawing the vehicle trajectory through the information reported by the vehicle node, fully protecting the privacy information of the car owner. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0067] Figure 1 is a flow chart of a method for protecting vehicle privacy data based on collective signature provided by an embodiment of the present invention;

[0068] Figure 2 is a schematic diagram of the structure of a system for protecting vehicle privacy data based on collective signatures provided by an embodiment of the present invention;

[0069] Figure 3 It is a schematic diagram of the process of putting a new vehicle application on the shelf provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0071] In the process of vehicle-cloud communication, one of the existing strategies is to use certificates to sign the transmitted data, and to confirm the identity of the sender of the data and the accuracy of the data content through the signature verification process. However, the certificate is bound to the vehicle-side information. When the vehicle uses the certificate to communicate with many cloud services, each cloud service will obtain and store the vehicle's certificate information, increasing the risk of vehicle data leakage. At the same time, when the vehicle uses the certificate to regularly send its location, status, and other information that needs to be reported to the data collection platform, the data collection platform can use the vehicle's certificate and the reported vehicle-side information to draw the vehicle's running trajectory, which poses a risk of leaking the owner's privacy.

[0072] Therefore, this scheme proposes a scheme that uses a collective public key instead of a certificate. When verifying the signature, only the public key is used without any information related to the signer. This can not only realize the identity authentication of the sender of the information and ensure the accuracy of the data content, but also the cloud service cannot confirm the specific identity of the sender of the information, thus protecting the privacy information of the car owner.

[0073] The method for protecting vehicle privacy data based on collective signature provided by the present invention is used when a management center and each node in the same collective communicate with each other.

[0074] The nodes include vehicle application nodes and vehicle nodes. The vehicle application nodes collect vehicle status information from vehicle nodes, and the vehicle application nodes and vehicle nodes request and receive messages. The management center is used to generate and maintain collective public keys and public private keys.

[0075] Depend on Figure 1 It can be seen that the method for protecting vehicle privacy data based on collective signature includes the following steps:

[0076] Step S1: Generate a collective public key and a public private key: The management center generates a pair of public keys and private keys through a large prime number generation algorithm as the collective public key and public private key, and publishes the public key within the group.

[0077] Furthermore, the management center generates a pair of public and private keys through a large prime number generation algorithm, including:

[0078] The management center generates a node ID for identification G . Management Center Identity ID G You can use the system number or other identification as long as the ID G It only needs to be unique within the group. In actual scenarios, this ID can be generated according to specific circumstances. G .

[0079] Randomly generate five different large prime numbers, namely p, q, k, u, and v.

[0080] In cryptography, large prime numbers are generally 512 bits or more. The larger the number of large prime numbers, the higher the security, but the more resources are consumed for calculation. In order to balance security and resources, this application chooses 512 bits, taking into account the difficulty of algorithm cracking and the needs of subsequent calculations.

[0081] Based on five different large prime numbers, we get the secret key n, and n=p×q=(2k×u+1)×(2k×v+1).

[0082] Let a large prime number k be the order of the group g.

[0083] Select integers e and c that satisfy ec=1modf(n), where f(n)=(p-1)×(q-1), and gcd(e,f(n))=1.

[0084] For ease of understanding, we will use the mod operation as a unified explanation here. ec=1modf(n) means that the remainder of the product of e and c divided by f(n) is equal to the remainder of 1 divided by f(n). gcd(e,f(n))=1 means that the greatest common divisor of e and f(n) is 1, that is, e and f(n) have no common prime factors. The calculation methods of mod and gcd used in subsequent formulas are the same as above and will not be repeated here.

[0085] Select a hash function h. There are no restrictions on the corresponding hash function. You can choose one based on the usage scenario, considering the resources used by the function and the difficulty of the function.

[0086] Select integer c as public private key d. Put secret key n, integer e, group g, large prime number k, hash function h and node ID G As a public key, represented as (n, e, g, k, h, ID G ). The brackets here indicate that the data in the brackets together constitute the public key and need to be made public.

[0087] Public public key (n, e, g, k, h, ID G ).

[0088] Figure 3 is a schematic diagram of a process for putting a new vehicle application on the shelf provided by an embodiment of the present invention, from Figure 3 It can be seen that when a new vehicle application is launched in the group, it first needs to register with the management center; the new vehicle application obtains its own private key authorized by the management center, and the management center stores the download address, service object, and its own public key and private key of the newly launched vehicle application, and notifies the service object of the application of the new application information, and the application information includes the download address of the application; the vehicle node receives the new application related information and signature sent by the management center and verifies the signature. After the verification is passed, the new application information sent by the management center is saved; the vehicle end can independently choose whether to download the new application and the download time; when downloading a new application, the vehicle node constructs a download request and signs it with its own private key, and sends the signed download request to the application download address provided by the management center. After receiving the download request, the application end verifies the signature to confirm that the application request comes from a vehicle in the group. After the verification is passed, the application installation package is signed with its own private key and the application installation package and signature are returned to the request sender. After receiving the application installation package and signature, the vehicle node verifies the signature and installs the application after the verification is passed.

[0089] Step S2: Node registration: When a new node is added to the collective, the new node needs to be registered. Specifically, the management center generates the corresponding node's own private key based on the node's own public key and public private key, and the management center stores the node used to represent the node identity. , the corresponding node’s own private key and its own public key.

[0090] Furthermore, the management center generates the corresponding node's own private key based on the node's own public key and public private key, and the management center stores the node used to represent the node identity. And the corresponding node's own public and private keys are:

[0091] Newly added nodes generate nodes for identity identification .

[0092] Randomly generate a random number less than k , according to k a Calculate the public key of the newly added node with group g , the calculation formula is:

[0093] ;

[0094] The management center uses the node ID of the management center G , your own public key And the public private key generates the private key of the newly added node , the formula is as follows:

[0095] ;

[0096] by As the node's own private key.

[0097] Management center storage node , the node's corresponding private key and public key, generating the node And the correspondence table between its own public and private keys.

[0098] Furthermore, the management center storage node , the node's own private key and its own public key, and also stores the application download address of the newly added vehicle application node and the corresponding service vehicle node. The management center notifies the vehicle node of the corresponding service of the newly added vehicle application node of the new message of the vehicle application node.

[0099] Furthermore, the management center notifies the vehicle node corresponding to the newly added vehicle application node of the newly added vehicle application node:

[0100] In the process of notifying the corresponding service object of the newly added vehicle application message, in order to ensure the credibility of the message, the management center needs to sign the message sent to the service object. The management center uses the public private key d and the hash function h to calculate the signature value s' of the newly added message of the vehicle application node. The calculation formula is:

[0101] ;

[0102] The management center notifies the vehicle node corresponding to the newly added vehicle application node of the newly added vehicle application node's new addition message and signature value s'.

[0103] Furthermore, the vehicle node of the corresponding service of the newly added vehicle application node performs a signature verification operation on the newly added message according to the hash function h in the public key. The formula is as follows:

[0104] ;

[0105] If the above formula is established, the signature verification operation is successful, and the vehicle node corresponding to the newly added vehicle application node performs corresponding message processing on the newly added message.

[0106] If the above formula is not true, the signature verification operation fails, and the vehicle node corresponding to the newly added vehicle application node does not perform corresponding message processing on the newly added message.

[0107] In the group signature verification process, a data signature verification process between the management center and the node is added. Considering that cloud service nodes in the group will be dynamically added or deleted, in order for vehicles to obtain changes in cloud services in a timely manner, when cloud services register with the management center, the management center needs to inform vehicles how to obtain newly added cloud services while ensuring the security of cloud service privacy information. Therefore, a signature verification process is added between the management center and vehicle nodes.

[0108] Step S3: Node message signature: When a message request is made between a vehicle application node and a vehicle node, the node message sent must be signed. Specifically, the sending node of the node message calculates the signature value of the node message through its own private key and public key, and sends the node message with the signature value.

[0109] Furthermore, the sending node of the node message calculates the signature value of the node message through its own private key and public key, including:

[0110] The sending node of the node message randomly generates two random numbers k1 and k2 that are less than k.

[0111] The signature value of the node message is calculated based on k1, k2, its own private key and public key. The formula is as follows:

[0112] ;

[0113] ;

[0114] ;

[0115] ;

[0116] V represents a temporary parameter, r, s1, s2 are signature value 1, signature value 2, and signature value 3 respectively, and m represents a node message;

[0117] The signature value of the node message is (r, s1, s2).

[0118] Step S4: Node message signature verification: Based on the public key and signature value, the receiving node of the node message performs a signature verification operation on the received node message with the signature value. After the signature verification is successful, the corresponding message processing is performed according to the node message, specifically:

[0119] The receiving node of the node message obtains the node ID of the management center G .

[0120] Calculate the temporary parameter V based on g and n in the public key and the signature value of the node message ` ,for:

[0121] ;

[0122] Judge r=h(V ` ,m) is true, if so, the signature verification is successful, and the receiving node of the node message performs corresponding message processing according to the node message; if not, the signature verification fails, and the receiving node of the node message does not process the node message.

[0123] Furthermore, the receiving node of the node message performs corresponding message processing according to the node message. If the vehicle application node receives the node message sent by the vehicle node and determines that the vehicle status information in the collected node message is abnormal, the vehicle application node applies to the management center for node identification, specifically:

[0124] The vehicle application node receives the node message sent by the vehicle node and performs the node message signature verification operation.

[0125] After the signature verification is successful, the node message sent by the vehicle node is parsed and identified, and the vehicle status information in the node message is determined to be abnormal information.

[0126] The vehicle application node sends the signature value corresponding to the abnormal information to the management center, and the management center obtains its own private key corresponding to the abnormal information based on the signature value.

[0127] The management center is based on the node The corresponding relationship table of its own public and private keys, combined with its own private key corresponding to the abnormal information, determines the node of the vehicle node corresponding to the abnormal information , and sent to the vehicle application node that collected the abnormal information.

[0128] The vehicle application node that collects the abnormal information is based on the node of the vehicle node corresponding to the abnormal information. , locate the specific location of the vehicle node corresponding to the abnormal information, and carry out the corresponding fault handling process.

[0129] By constructing a collective public key and public private key for a group, when the vehicle application node and the vehicle node communicate, any node uses its own private key and public key to sign and send a signed message. Another node in the group can verify the signature using only the public key without any information related to the signer, which fully protects the privacy data of the node while ensuring the credibility of the source of the message and the integrity of the information. The vehicle application node no longer needs to collect certificate information with vehicle node identity identification for message security verification, that is, the vehicle node identity identification information and vehicle status information are isolated. In the scenario where the vehicle node needs to regularly report the vehicle location, status and other information to the vehicle application node, while realizing the vehicle node identity authentication and reporting data accuracy verification, the vehicle application node is prevented from drawing the vehicle trajectory through the information reported by the vehicle node, which fully protects the privacy information of the car owner.

[0130] The present application also provides a system for protecting vehicle privacy data based on collective signatures, which is used to execute any of the above methods for protecting vehicle privacy data based on collective signatures, comprising: Figure 2 It can be seen that the system includes:

[0131] Collective public key and public private key generation module: The management center generates a pair of public keys and private keys through a large prime number generation algorithm as the collective public key and public private key, and makes the public key public within the collective;

[0132] Node registration module: connected to the collective public key and public private key generation module. When a new node is added to the collective, the new node needs to perform node registration operation. Specifically, the management center generates the corresponding node’s own private key based on the node’s own public key and public private key. The management center stores the node used to represent the node identity. , the corresponding node’s own private key and its own public key;

[0133] Node message signature module: connected to the node registration module. When the vehicle application node and the vehicle node make a message request, the node message sent must be signed. Specifically, the sending node of the node message calculates the signature value of the node message through its own private key and public key, and sends the node message with the signature value.

[0134] Node message signature verification module; connected to the node message signature module, based on the public key and signature value, the receiving node of the node message verifies the received node message with the signature value, and performs corresponding message processing according to the node message after the signature verification is successful.

[0135] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0136] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0137] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A method for protecting vehicle privacy data based on collective signature, characterized in that: Used for communication between the management center and nodes in the same group; The nodes include a vehicle application node and a vehicle node, the vehicle application node collects vehicle status information of the vehicle node, and the vehicle application node and the vehicle node request and receive messages; the management center is used to generate and maintain the collective public key and public private key; The method for protecting vehicle privacy data based on collective signature comprises the following steps: Generate a public key and a public private key of the group: the management center generates a pair of public keys and private keys through a large prime number generation algorithm as the public key and public private key of the group, and discloses the public key within the group; The management center generates a pair of public and private keys through a large prime number generation algorithm, specifically including: The management center generates a node ID for identification G ; Randomly generate five different large prime numbers, namely p, q, k, u, and v; According to the five different large prime numbers, a secret key n is obtained, and n=p×q=(2k×u+1)×(2k×v+1); Let the large prime number k be the order of the group g; Select integers e and c such that ec = 1 mod f (n), where f (n) = (p-1) × (q-1), and gcd (e, f (n)) = 1; Select a hash function h; Select an integer c as the public private key d; The secret key n, integer e, group g, large prime number k, hash function h and node ID G As the public key, it is represented by (n, e, g, k, h, ID G ); Publicize the public key (n, e, g, k, h, ID) within the group G ); Node registration: When a new node is added to the collective, the new node needs to perform a node registration operation, specifically: the management center generates the corresponding node's own private key based on the node's own public key and the public private key, and the management center stores the node used to represent the node identity. , the corresponding node's own private key and its own public key, including: Newly added nodes generate nodes for identity identification ; Randomly generate a random number less than k , according to the The public key of the newly added node is calculated with the group g , the calculation formula is: ； The management center uses the node ID of the management center G , your own public key And the public private key generates the private key of the newly added node , the formula is as follows: ； As mentioned As the node's own private key; Management center storage node , the node's corresponding private key and public key, generating the node The corresponding relationship table with its own public and private keys; Node message signature: When a message is requested between a vehicle application node and a vehicle node, the node message sent must be signed. Specifically, the sending node of the node message calculates the signature value of the node message through its own private key and the public key, and sends the node message with the signature value. Node message signature verification: Based on the public key and signature value, the receiving node of the node message performs a signature verification operation on the received node message with the signature value. After the signature verification is successful, the corresponding message processing is performed according to the node message.

2. The method for protecting vehicle privacy data based on collective signature according to claim 1, characterized in that: The sending node of the node message calculates the signature value of the node message by using its own private key and the public key, including: The sending node of the node message randomly generates two random numbers k1 and k2 that are less than k; The signature value of the node message is calculated based on k1, k2, the private key and the public key. The formula is as follows: ； ； ； ； V represents a temporary parameter, r, s1, s2 are signature value 1, signature value 2, and signature value 3 respectively, and m represents a node message; The signature value of the node message is (r, s1, s2).

3. The method for protecting vehicle privacy data based on collective signature according to claim 2 is characterized in that: According to the public key and the signature value, the receiving node of the node message performs a signature verification operation on the received node message with the signature value, specifically: The receiving node of the node message obtains the node ID of the management center G ; The temporary parameter V is calculated based on g and n in the public key and the signature value of the node message. ` ,for: ； Judge r=h(V ` ,m) is true, if so, the signature verification is successful, and the receiving node of the node message performs corresponding message processing according to the node message; if not, the signature verification fails, and the receiving node of the node message does not process the node message.

4. The method for protecting vehicle privacy data based on collective signature according to claim 1, characterized in that: Management center storage node , the node's own private key and its own public key, and also stores the application download address of the newly added vehicle application node and the corresponding service vehicle node. The management center notifies the vehicle node of the corresponding service of the newly added vehicle application node of the new message of the vehicle application node.

5. The method for protecting vehicle privacy data based on collective signature according to claim 4 is characterized in that: The management center notifies the vehicle node corresponding to the newly added vehicle application node of the new vehicle application node: The management center uses the public private key d and the hash function h to calculate the signature value s' of the new message of the vehicle application node. The calculation formula is: s'=(h(m)) d fashionable; The management center notifies the vehicle node corresponding to the newly added vehicle application node of the newly added message and signature value s'.

6. The method for protecting vehicle privacy data based on collective signature according to claim 5, characterized in that: The vehicle node corresponding to the newly added vehicle application node performs a signature verification operation on the newly added message according to the hash function h in the public key, and the formula is as follows: ； If the above formula is established, the signature verification operation is successful, and the vehicle node corresponding to the newly added vehicle application node performs corresponding message processing on the newly added message; If the above formula is not true, the signature verification operation fails, and the vehicle node corresponding to the newly added vehicle application node does not perform corresponding message processing on the newly added message.

7. The method for protecting vehicle privacy data based on collective signature according to claim 3 is characterized in that: The receiving node of the node message performs corresponding message processing according to the node message. If the vehicle application node receives the node message sent by the vehicle node and determines that the vehicle status information in the collected node message is abnormal, the vehicle application node applies to the management center for node identification, specifically: The vehicle application node receives the node message sent by the vehicle node and performs a node message signature verification operation; After the signature verification is successful, the node message sent by the vehicle node is parsed and identified, and the vehicle status information in the node message is determined to be abnormal information; The vehicle application node sends the signature value corresponding to the abnormal information to the management center, and the management center obtains its own private key corresponding to the abnormal information according to the signature value; The management center The corresponding relationship table of its own public and private keys, combined with its own private key corresponding to the abnormal information, determines the node of the vehicle node corresponding to the abnormal information , and sent to the vehicle application node that collected the abnormal information; The vehicle application node that collects the abnormal information is based on the node of the vehicle node corresponding to the abnormal information. , locate the specific location of the vehicle node corresponding to the abnormal information, and carry out the corresponding fault handling process.

8. A system for protecting vehicle privacy data based on collective signature, characterized in that: The method for protecting vehicle privacy data based on collective signature according to any one of claims 1 to 7 is implemented, wherein the system comprises: Collective public key and public private key generation module: The management center generates a pair of public keys and private keys through a large prime number generation algorithm as the collective public key and public private key, and makes the public key public within the collective; The management center generates a pair of public and private keys through a large prime number generation algorithm, specifically including: The management center generates a node ID for identification G ; Randomly generate five different large prime numbers, namely p, q, k, u, and v; According to the five different large prime numbers, a secret key n is obtained, and n=p×q=(2k×u+1)×(2k×v+1); Let the large prime number k be the order of the group g; Select integers e and c such that ec = 1 mod f (n), where f (n) = (p-1) × (q-1), and gcd (e, f (n)) = 1; Select a hash function h; Select an integer c as the public private key d; The secret key n, integer e, group g, large prime number k, hash function h and node ID G As the public key, it is represented by (n, e, g, k, h, ID G ); Publicize the public key (n, e, g, k, h, ID) within the group G ); Node registration module: connected to the collective public key and public private key generation module. When a new node is added to the collective, the new node needs to perform node registration operation. Specifically, the management center generates the corresponding node’s own private key based on the node’s own public key and public private key. The management center stores the node used to represent the node identity. , the corresponding node's own private key and its own public key, including: Newly added nodes generate nodes for identity identification ; Randomly generate a random number less than k , according to the The public key of the newly added node is calculated with the group g , the calculation formula is: ； The management center uses the node ID of the management center G , your own public key And the public private key generates the private key of the newly added node , the formula is as follows: ； As mentioned As the node's own private key; Management center storage node , the node's corresponding private key and public key, generating the node The corresponding relationship table with its own public and private keys; Node message signature module: connected to the node registration module. When the vehicle application node and the vehicle node make a message request, the node message sent must be signed. Specifically, the sending node of the node message calculates the signature value of the node message through its own private key and public key, and sends the node message with the signature value. Node message signature verification module; connected to the node message signature module, based on the public key and signature value, the receiving node of the node message verifies the received node message with the signature value, and performs corresponding message processing according to the node message after the signature verification is successful.

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