WO2020244295A1

WO2020244295A1 - Distributed ledger technology-based sensor network security management method and security system

Info

Publication number: WO2020244295A1
Application number: PCT/CN2020/082417
Authority: WO
Inventors: 沈国锋; 周明拓
Original assignee: 中国科学院上海微系统与信息技术研究所
Priority date: 2019-06-06
Filing date: 2020-03-31
Publication date: 2020-12-10
Also published as: CN110445827A; CN110445827B

Abstract

A distributed ledger technology-based sensor network security management method and security system. The method comprises: selecting a top layer server and a regional server as alliance chain nodes to build an alliance chain and store a distributed ledger; generating an asymmetric key for a sensor node and a sink node of a lower layer of the regional server, solidifying a private key in a memory, and writing a public key into the alliance chain; uploading data collected by the sensor node to the regional server by means of the sink node, and after passing verification, storing a data set in a database under a chain of the regional server, encrypting same, calculating a hash value of the data set and writing same into the alliance chain as a storage certificate; and decrypting the data set and calculating the hash value thereof, then comparing to the storage certificate to verify the correctness thereof, and returning a uniform resource locator. The security management method provides a centralized and effective device management mechanism and data security verification for large-scale sensor networks, and solves the problem of data sharing access control.

Description

Security management method and security system of sensor network based on distributed ledger technology

Technical field

The invention belongs to the technical field of the Internet of Things, and specifically relates to a security management method and a security system of a sensor network based on distributed ledger technology.

Background technique

Wireless sensor network technology plays an important role in environmental monitoring and governance. Wireless Sensor Network (Wireless Sensor Network, WSN) refers to the use of a group of widely distributed dedicated sensors to monitor and record the physical information of the environment, and to process the collected data in a central location [Sun Hanlin, Zhang Peng, Yan Zheng, Etc. A wireless sensor network architecture based on cloud computing[J]. Computer Application Research, 2013,30(12):3720-3723]. The wireless sensor network is composed of nodes as the basic unit, which is divided into sensor nodes and sink nodes. Among them, the sensor node is equipped with one or more sensors, including a radio transceiver and a microcontroller, and is powered by a battery or an integrated energy harvester (such as a photovoltaic power generation panel). The sink node is responsible for collecting the data of the sensor nodes in the area and sending the data to the back-end server through the wide area network.

There are equipment management and data security issues in large-scale deployment of sensor networks. The network first needs to verify legal data input devices to resist malicious devices; during the process of data collection, transmission, and storage, the supervisor and the supervised party in the environmental monitoring network may cause damage to the sensing equipment due to conflicts of interest. Subject to human tampering, data security mechanisms need to be adopted to ensure data credibility. At the same time, the privacy protection of monitoring data is also a challenge. In addition, the wide distribution of the sensor network also increases the difficulty of management and maintenance to a certain extent. For example, the patent document with the application number CN201710265307.8 discloses a method for controlling the authority of alliance chain based on digital certificate and CA certification system. Taking water environment monitoring as an example, most local-level water quality monitoring sites entrust third-party companies to plan The design lacks a unified standard, especially the monitoring points of the sewage outlets of the enterprises, which are checked and accepted by the government after the enterprises install them. In terms of system structure, the collected monitoring data is uploaded to the computer room of the Water Affairs Bureau through the public network. The data between different regions and between the superior and the subordinate is isolated from each other, and the original data is insufficient in sharing and auditing. At the same time, the local self-built water monitoring system has potential risks of data tampering and falsification, which greatly reduces the credibility of data and makes it difficult to maximize the supervision and governance role of the automatic monitoring network.

The nodes in wireless sensor networks (such as environmental monitoring sensor networks) are widely distributed geographically. Large-scale monitoring networks often involve multi-layer supervision relationships. Therefore, how to implement large-scale equipment management to ensure that data is collected, transmitted, and Security in storage and protecting data privacy while supporting data sharing are several major difficulties.

An existing technology is to use the traditional centralized CA mechanism and cloud storage. For example, the patent document with application number CN201710132078.2 discloses a distributed storage system and method for massive heterogeneous sensor data in the Internet of Things, and the patent document with application number CN201810138502.9 discloses a cloud-based computing And wireless sensor network mountain torrent disaster monitoring system. The environmental monitoring sensor network deployed based on private cloud technology allows managers to obtain centralized control, but there are deficiencies in performance and cost. In this mode, the sensor data is collected after being encrypted and directly transmitted to the cloud computer room for processing and storage, which can effectively prevent data tampering and forgery. However, it is necessary to ensure reliable network connection to transmit data scattered in geographical locations to the cloud computing center; cloud computing servers that support large-scale sensor node access also require a large cost investment, so transmission in the existing large-scale environment In the sensor network, it is difficult to strike a balance between data security and efficiency costs using cloud computing. In addition, the use of centralized servers to implement security mechanisms such as node authentication, node management, and access control has the risk of a single point of failure, and cloud servers may also become clear targets.

Another existing technology is a sensor network managed by region. For example, the patent document with application number CN201210569403.9 discloses a distributed wireless sensor network, which adopts regional autonomous deployment by setting up distributed servers in various places The method can balance network traffic, reduce construction costs, and eliminate the risk of single points of failure. However, the management authority is also decentralized, which introduces the risk of data tampering. Therefore, there are also deficiencies in global control, data sharing, and data reliability, which makes intensive monitoring of data It is difficult to maximize the benefits [Zhao Kuo, Xing Yongheng, "Summary of Internet of Things Security Research Driven by Blockchain Technology", Information Network Security, 2017(5): 1-6. and Wang Chuanzheng, "Wireless Sensor Network Data Storage and Visiting Technology Research, Nanjing University of Posts and Telecommunications, 2012.].

In summary, the use of cloud computing mode to deploy sensor networks has cost defects and single-point failure risks, while regional autonomous sensor networks have insufficient data security and manageability.

Among them, distributed ledger technology is a data recording method that does not need to be stored or confirmed by any centralized entity. The consortium chain in distributed ledger technology has the characteristics of decentralization, autonomy, and information that cannot be tampered with. In the single-node perspective, data is encrypted by an asymmetric key and stored in the consortium chain, which is connected end to end in the form of a Hash chain, so historical data is encrypted and stored and cannot be tampered with; from the overall point of view, the consortium chain is a private network , Each node participates in data recording after permission, and builds a consistent and credible data record on the basis of no trust through the consensus mechanism. Introducing distributed ledger technology as a supporting technology into the wireless sensor network can effectively reduce the risk of data tampering, solve data privacy issues, and ensure data security compared to the traditional database and certificate authority (CA) scheme. The smart contract in QQ provides a flexible and effective means for data sharing and auditing. However, in the actual application process, there is no custom-designed blockchain network deployment and smart contract (chain code) writing for achieving security enhancement. Therefore, the existing sensor network using alliance chain technology cannot achieve security enhancement or provide a controllable data sharing function.

Summary of the invention

The present invention aims to provide a security management method and security system for a sensor network based on distributed ledger technology, thereby providing a centralized and effective device management mechanism for a large-scale sensor network, providing data security verification, and solving data sharing access control The problem.

In order to achieve the above objective, the present invention provides a security management method for a sensor network based on distributed ledger technology, including:

S1: Select a top-level server and multiple regional servers as alliance chain nodes to build the alliance chain, and store distributed ledgers on it;

S2: Generate a pair of asymmetric keys for each sensor node and sink node in the lower layer of the regional server, solidify the private key in the memory of the sink node and the sensor node, and write the public key and its address To the alliance chain;

S3: The sensor node collects data, uploads the data collected by the sensor node to the sink node and obtains the data set of the sink node, and then uploads it to the regional server for data verification. After the verification is passed, the data of the sink node The set is stored in the off-chain database of the regional server and encrypted. At the same time, the hash value of the data set of the sink node is calculated and written into the alliance chain as a proof;

S4: Decrypt a shared data set in the off-chain database and calculate the hash value of the shared data set, then compare the hash value with the evidence in step S3 to verify the correctness of the shared data set, and Return the uniform resource locator of the shared data set to realize data sharing.

Preferably, the security management method of the sensor network based on distributed ledger technology further includes step S31: in the process of data verification in step S3, if an abnormality is found, the abnormal information is written into the alliance chain.

In the step S1, the consortium chain is divided into multiple independent side chains with different parameters according to the security services running on the consortium chain.

In the step S1, the top-level server and the regional server are authorized to be selected as alliance chain nodes, and each alliance chain node adopts a consensus algorithm to realize the consensus of the distributed ledger.

The consensus algorithm is a lightweight algorithm.

In the step S2, the writing the public key and its address into the consortium chain includes:

S21: The user uses the identity management smart contract to enter the public key and address of the sink node that is permitted to join in the sensor network, the sink node goes online and registers the identity with the regional server;

S22: Step S22: Each sink node reads its surrounding sensor nodes, and the sensor nodes wake up and access the sink node.

In step S21, the registration identity includes: the sink node first sends an encrypted request registration information to the regional server, and the encrypted request registration information is encrypted with the sink node's private key as the message payload, and the payload is signed hash value and verify the identity of the sender, then, the regional server verifies the authenticity of the requested registration information according to the entered public key of the sink node, and completes the registration identity when the verification is passed;

In the step S22, the access to the sink node includes: the sensor node sends an encrypted identity verification request to the sink node, and the encryption method of the identity verification request is the same as the encryption method of the requested registration information; The node verifies the authenticity of the identity verification request, and enables the sensor node to access the sink node when the verification passes.

In the step S3, the data verification of the sink node is used to verify the source and integrity of the data collected by the sensor node, and after the verification is passed, the sink node's data is obtained by signing the digest of the data load with its own private key. data set.

In the step S3, the operations of data verification, hash value calculation, and writing to the blockchain all run in a trusted execution environment on the regional server.

The step S4 is implemented by a data sharing smart contract, and the scope, time limit, and visitor identity of the data sharing can be preset by using the data sharing smart contract.

On the other hand, the present invention also provides a sensor network security system based on distributed ledger technology. The sensor network includes a bottom-up hierarchical structure of sensor nodes, aggregation nodes, regional servers, and top-level servers. Including the alliance chain and the device trust transfer function module, the safe storage function module, and the data access control function module deployed on the alliance chain;

The alliance chain includes alliance chain nodes and a blockchain network established between the alliance chain nodes, and the alliance chain nodes are selected top-level servers and regional servers;

The device trust transfer function module includes an asymmetric key generator and an identity management smart contract. The asymmetric key generator is set to generate a pair of unique asymmetric keys for each sensor node and sink node in the lower layer of the regional server. The identity management smart contract is set to write the public keys and addresses of the sink node and the sensor node into the alliance chain;

The secure storage function module includes a data upload module, which is configured to upload the data collected by the sensor node to the sink node and obtain the data set of the sink node, and then upload it to the regional server to verify the data. Then the data set of the sink node is stored in the off-chain database of the regional server and encrypted, and the hash value of the data set of the sink node is calculated and written into the alliance chain as a proof;

The data access control function module is configured to decrypt a shared data set in the off-chain database and calculate the hash value of the shared data set, and then compare the hash value with the certificate in step S3 to verify the sharing Correctness of the data set, and return the uniform resource locator of the shared data set to realize data sharing.

The safe storage function module also includes an abnormality reporting module, which is configured to write the information into the alliance chain if an abnormality is found during the data verification process of the data upload module.

The alliance chain is divided into multiple independent side chains with different parameters.

The identity management smart contract includes a sink node identity registration module and a sensor node identity verification module. The sink node identity registration module is set to enter into the sensor network the public key and address of the sink node that is permitted to join, and make the sink node in When going online, register the identity with the regional server; the sensor node identity verification module is configured to enable each sink node to read its surrounding sensor nodes, and make the sensor node access the sink node when it wakes up.

The sink node identity registration module is further configured to: make the sink node first send an encrypted request registration information to the regional server, and the encrypted request registration information is encrypted with the sink node's private key as the message payload and signed Load the hash value and verify the identity of the sender, the regional server verifies the authenticity of the requested registration information according to the entered public key of the sink node, and completes the registration identity when the verification passes;

The sink node identity registration module is further configured to: cause the sensor node to send an encrypted identity verification request to the sink node, the encryption method of the identity verification request is the same as the encryption method of the requested registration information, and the sink node verifies that The authenticity of the identity verification request is described, and the sensor node is connected to the sink node when the verification is passed.

The present invention introduces distributed ledger technology on the basis of regional autonomous deployment of sensor networks, generates asymmetric keys for the convergence node and sensor nodes, solidifies the private key in the node memory, and writes the public key to the blockchain, and Use identity management smart contracts to establish a trust transfer chain from regional managers to aggregation nodes and then to sensor nodes to transfer trusted identities, solve the problem of centralized management in distributed IoT organizations, and ensure data transmission security; After the data is signed and encrypted, it is stored in the regional server, and the data summary is written into the alliance chain as a storage certificate, thereby providing data security verification; with the help of distributed ledger technology, the barriers to data sharing between different regions are eliminated, through a Data sharing smart contracts allow data owners to flexibly set data access permissions, sharing scope and time limit, which solves data sharing access control, and uses deposit certificates to verify shared data to ensure data credibility. During the data upload process, key operations on the regional server run in a trusted execution environment to ensure that the code and data are not tampered with.

Description of the drawings

Figure 1 is a schematic diagram of a typical sensor network.

Fig. 2 is a flowchart of a security management method for a sensor network based on distributed ledger technology according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a sensor network security system based on distributed ledger technology according to an embodiment of the present invention.

Detailed ways

Hereinafter, in conjunction with the accompanying drawings, the preferred embodiments of the present invention are given and described in detail, so as to better understand the functions and characteristics of the present invention.

Before describing the specific content of the invention, first explain the composition of the sensor network system. In a large-scale sensor network, it includes but is not limited to the following elements: sensor nodes, aggregation nodes, regional servers and regional managers, top-level servers and global managers, and alliance chains.

Figure 1 shows a typical sensor network, which shows the network topology and components of the sensor network. The sensor network is basically consistent with the existing layered sensor network structure, including the following The upper layered architecture has multiple sensor nodes Sen_i, multiple sink nodes Sink_j, multiple regional servers Org_k, and a top-level server Adm. Among them, the sensor node Sen_i is the data producer, which directly perceives the variables of the physical world through the sensor, and is generally designed for low power consumption and low cost; the aggregation node collects the data of the sensor node and forwards it to the background processing center. The node has more abundant energy and computing power; the regional server is responsible for receiving and processing the sensor data of some areas in the large-scale sensor network, and it is maintained and managed by the regional manager (that is, the actual management organization or personnel) of the corresponding regional server Sensor network facilities in this area; the top-level server is a server set up by the higher-level organizational department. It does not actually participate in the processing and storage of sensor data, but runs related supervision services. The global manager uses the top-level server owned by it to supervise and operate the business. Review the complete sensor network, leadership and regional managers. In addition, a consortium chain can be set up between multiple regional servers Org_k and a top-level server Adm, which has the characteristics of decentralization and non-tampering information.

The present invention proposes a sensor network security management method based on distributed ledger technology, which is used to implement sensor network device management and data access control functions. The security management method of the sensor network based on distributed ledger technology is shown in Figure 2, which specifically includes the following steps:

Step S1: Consortium chain deployment. Select a top-level server and multiple regional servers as alliance chain nodes to build the alliance chain, and store distributed ledgers on it.

Among them, the alliance chain includes alliance chain nodes and a blockchain network established between alliance chain nodes (that is, a dedicated high-speed network, generally high-speed Ethernet or cellular network), which is divided into security services running on the alliance chain Multiple independent side chains (channels) with different parameters to adapt to business characteristics, such as device management chain to realize device management mechanism, data storage chain to realize the storage of sensor data summary, and data sharing chain to realize data access control. The consortium chain adopts an access permission mechanism, so the top-level server and regional server are authorized to be selected as consortium chain nodes. Each alliance chain node participates in the construction process of the distributed ledger, and adopts a consensus algorithm to realize the consensus of the distributed ledger. The consensus of the distributed ledger means that the data of the distributed ledger reaches a consensus on multiple nodes. The nodes are stored as multiple consistent ledgers. Since the consortium chain uses an admission permission mechanism to make each consortium chain node relatively credible, the consensus algorithm used does not need to be a proof of work (PoW) mechanism, but can be a lightweight algorithm such as Byzantine Fault Tolerance (PBFT). Then reduce the requirements for system hardware.

In addition, the step S1 also includes: deploying a smart contract on the consortium chain for operating the data of the distributed ledger on the blockchain. The smart contract includes an identity management smart contract and a data sharing smart contract, which are respectively used for The initialization and identity verification and data sharing of the sensor network below.

Step S2: Identity identification, initialization and identity verification of the sensor network.

A pair of asymmetric keys is generated for each sensor node and sink node in the lower layer of the selected area server to use for the identity of these sensor nodes and sink nodes in the alliance chain; the private key is fixed in the sink In the memory of nodes and sensor nodes, it is used as secret, unique and unchangeable identity verification information to prove the identity of the holder, and only the program of the sink node and the sensor node can read it; and the public key and its The address is written into the consortium chain, where the address is a unique identification code calculated based on the public key. The public key and its address are disclosed as the identification of the sink node and the sensor node and used to manage the sensor node and the sink node; new After the deployed sensor network node wakes up, it requests identity verification, performs identity verification step by step by comparing the node information on the alliance chain, registers as a legal node, and completes the initialization of the sensor network.

The writing of the public key and its address into the consortium chain is realized through an identity management smart contract, and a cryptographic identity verification method is adopted to realize the trust transfer of user-sink node-sensor node, which specifically includes:

Step S21: The user (ie, the area manager) uses the identity management smart contract to enter the public key and address of the sink node that is permitted to join in the sensor network, the sink node goes online and registers the identity with the area server. In this way, the interaction between users, aggregation nodes and identity management smart contracts is realized.

In step S21, the sensor network is generally designed as a limited, low-rate, multi-hop wireless network. The user uses the identity management smart contract of the corresponding business authority through the respective user key, wherein the business authority is preset by the global server.

The registration identity includes: the sink node first sends an encrypted request registration information to the regional server, the encrypted request registration information is encrypted with the sink node's private key as the message payload, and the hash value of the message payload is signed. The signature operation on the hash value of the message payload is used to verify the integrity of the information and verify the identity of the sender. The message payload also includes a timestamp to prevent replay attacks; then, the regional server is based on the entered aggregation node The public key verifies the authenticity of the requested registration information, and completes the registration identity when the verification passes.

Step S22: Each sink node reads its surrounding sensor nodes, and the sensor nodes wake up and access the sink node.

In step S22, each sink node interacts with a smart contract to query the data on the alliance chain to read its surrounding sensor nodes.

The access to the sink node includes: the sensor node sends an encrypted identity verification request to the sink node, and the encryption method of the identity verification request is the same as the encryption method of the registration information request sent by the sink node to the regional server; The sink node verifies the authenticity of the identity verification request, and enables the sensor node to access the sink node when the verification passes, so that the sensor node can perform data forwarding tasks. In addition, if the verification fails, the address of the sensor node will be blacklisted after multiple failed attempts, and the connection will be refused again. Thus, the identity verification of the sensor node is completed, and the joining of malicious nodes is resisted according to the identity verification.

In this embodiment, the encrypted registration request information is:

Sign _{Sink_j} (Hash(data))|E _{pri_Sink_k} (data)|Add _{sink_j} ,data=Add _{sink_j} |registerRequest|TimeStamp

Among them, Sign _{sink_j} () is the signature operation of the sink node sink_j, Hash(·) is the hash operation; data is the message payload; E _{pri_sink_j} (·) is encryption using the private key of the sink node sink_j; Add _{sink_j} is the sink node sink_j Address identification; registerRequest is the request registration information, Timestamp is the timestamp.

The encrypted identity verification request is:

Sign _{Sen_i} (Hash(data))|E _{pri_Sink_j} (data)|Add _{Sen_i} ,data=Add _{Sen_i} |Authentication Request|TimeStamp,

Among them, Sign _{sen_i} () is the signature operation of the sensor node sen_i, Hash (·) is the hash operation; data is the message payload; E _{pri_sen_i} (·) is the encryption using the private key of the sensor node sen_i; Add _{sen_i} is the sensor The address identifier of the node sen_i; Authentication Request is the authentication request, and Timestamp is the timestamp. The following table shows the symbols and their meanings used in this embodiment.

Table 1 Symbols used in the embodiments and their meanings

Step S3: Data upload. The sensor node collects data, uploads the data collected by the sensor node to the sink node for data verification, and obtains the data set of the sink node, and then uploads it to the regional server for data verification. After the verification is passed, the data set of the sink node is stored It is encrypted in the off-chain database of the regional server, and the hash value of the data set of the sink node is calculated and written into the alliance chain as a proof.

Among them, the data verification of the sink node is used to verify the source and integrity of the data collected by the sensor node, and after the verification is passed, the data set of the sink node is obtained by signing the digest of the data load with its own private key. The data verification of the regional server is used to verify the validity of the data set of the sink node. The off-chain database is encrypted with a database password.

Therefore, the above main communication messages and operations are expressed as:

Among them, the data set of the sensor node passed to the sink node is:

Sen_i->sink_j:Sign _{Sen_i} (Hash(data_sen_i|TimeStamp))|data_sen_i|TimeStamp,

The data set of the sink node routed to the regional server is:

Sink_j->Org_k:Sign _{Sink_j} (Hash(data_sink_j|TimeStamp))|data_sink_j|TimeStamp,

The hash value sent by the regional server to the alliance chain is:

Org_k->Chian:Sign _{Org_k} (Hash([Sign _{sink_k} (Hash(data_sink_j|TimeStamp))])),

The data set of the sink node stored in the off-chain database of the regional server is:

Org_k->Database:E _symKey ([Hash(data_sink_j|TimeStamp)|data_sink_j|TimeStamp]).

The meaning of each symbol mark is shown in Table 1.

In this step S3, the confidentiality and integrity of the data transmission process are protected by external transmission protocols (such as HTTPS, MQTT) encryption, and no additional consideration is required in the security mechanism of the present invention.

In this embodiment, the interval granularity of the deposit may be divided according to the actual situation, according to the time interval or according to the data size. In order to ensure the credibility of the operating results of the regional server, the operations of data verification, hash value calculation and writing to the blockchain all run in a trusted execution environment on the regional server, and the hardware level ensures that the code and data have not been tampered with. The trusted execution environment refers to the hardware-level security technology provided by the regional server processor, which can provide an isolated operating space for programs and data to ensure the credibility of execution results. For example, Intel SGX is an available trusted execution environment technology. It can ensure that the code and data are not violated at the hardware level.

In addition, the step S3 further includes a step S31: abnormal report. In the process of data verification in step S3, if an abnormality is found, such as data being tampered with, a certain node is offline, etc., the abnormal information is written into the alliance chain, and then transmitted to the entire network for fault handling services deal with.

As a result, in the event of an abnormal situation such as data being tampered with, a node is offline, etc., the regional server can write the abnormal situation to the alliance chain in time and pass it to the entire alliance chain for the sensor network operation and maintenance department to receive the message in time Survey and maintenance.

Step S4: Data access control. Decrypt a shared data set in the off-chain database and calculate the hash value of the shared data set, then compare the hash value with the evidence in step S3 to verify the correctness of the shared data set, and return to all The uniform resource locator of the shared data set is described to realize data sharing.

Specifically, the shared data set is [data_sink_j|TimeStamp], and the decryption is specifically implemented by performing D _symKey ([Hash(data_sink_j|TimeStamp)|data_sink_j|TimeStamp]) operation, where D _symKey (·) is a Symmetric key symKey decryption, Hash(·) is a hash operation, Data_Sink_j is the data set of sink node j, and Timestamp is a timestamp.

Further, the step S4 is implemented through a data sharing smart contract, and the scope, time limit and visitor identity of the data sharing can be preset by using the data sharing smart contract to achieve the purpose of maintaining data ownership, and The operation of obtaining the shared data set itself will also leave a record in the blockchain, which gives the data sharing security and traceability.

In practical applications, the sharing of the shared data set can be actively disclosed by the data owner, or the user (ie, the global manager or other regional managers) can initiate an access request. No matter what the motivation is, the data owner can specify the scope, time limit and visitor identity of the data sharing through the above data sharing smart contract. Users with access rights use the data sharing smart contract to trigger the data reading program on the corresponding regional server. Since the off-chain database on the regional server is encrypted with a password, the data reading program will be accessed from the regional management server when it starts normally. Obtain the password, so the data reading program obtains the read permission of the off-chain database in the S4, and then obtains the shared data set, and uses the data digest stored on the chain to verify the integrity and credibility of the data, and send it to the data The requester returns the uniform resource locator of the shared data set.

The present invention also proposes a sensor network security system for realizing the above-mentioned security management method, including: alliance chain, and device trust transfer function module 2 deployed on the alliance chain, safe storage function module 3, and data access control Function module 4, as shown in Figure 3.

The alliance chain 1 includes alliance chain nodes and a blockchain network established between the alliance chain nodes and adopting an access permission mechanism. The alliance chain nodes are selected regional servers and top-level servers. The alliance chain 1 is divided into multiple channels according to security services. It uses distributed ledger technology to store distributed ledger. In addition, the alliance chain adopts a lightweight data consensus algorithm to reduce the consumption of hardware resources. As a result, the alliance chain, with its decentralization and non-tamperable characteristics of information, serves as the trusted basis of the security system of the sensor network of the present invention, and then supports other modules in the system, providing it with functions such as information storage and information sharing. .

The device trust transfer module 2 includes an asymmetric key generator and an identity management smart contract, which is used to manage sensor nodes and sink nodes.

The asymmetric key generator is set to generate a pair of unique asymmetric keys for each sensor node and sink node in the lower layer of the regional server, wherein the private key is solidified in the memory, and the public key and its address are used as The identities of sensor nodes and sink nodes are disclosed, and the address is a unique identification code calculated based on the public key.

The identity management smart contract is configured to write the public keys and addresses of the sink node and the sensor node into the consortium chain, which includes the sink node identity registration module and the sensor node identity verification module.

The sink node identity registration module is configured to enter the public key and address of the sink node that is permitted to join into the sensor network, and make the sink node register its identity with the regional server when it goes online. Among them, the sensor network is generally designed as a limited, low-rate, multi-hop wireless network. The identity management smart contract contains user keys corresponding to its multiple service permissions, and the service permissions are preset by the global server.

The sink node identity registration module is further configured to: make the sink node first send an encrypted request registration information to the regional server, and the encrypted request registration information is encrypted with the sink node's private key as the message payload and signed The hash value of the payload. The signature operation of the hash value of the message payload is used to verify the integrity of the message and verify the identity of the sender. The message payload also includes a timestamp to prevent replay attacks; subsequently, the regional server is based on the input The public key of the sink node verifies the authenticity of the requested registration information, and completes the registration identity when the verification passes.

The sensor node identity verification module is configured to enable each sink node to read its surrounding sensor nodes and enable the sensor nodes to access the sink node when they wake up. The sink node identity registration module is further configured to: make the sensor node send an encrypted identity verification request to the sink node, and the encryption method of the identity verification request is similar to the request registration information sent by the sink node to the regional server above ; The sink node verifies the authenticity of the identity verification request. If the verification is passed, the sink node performs the data forwarding task for the sensor node; if the sensor node address is not in the sink node's list, the sensor node network address will be blacklisted after repeated attempts and refused to connect again.

Therefore, through the above-mentioned device trust transfer function module, the sink node first registers its identity with the regional server after it goes online, and then accepts the access of the sensor node and verifies its identity. Through the device trust transfer function module, the trust of the device is transferred from the regional server to the sink node, and then to the sensor node.

The safe storage function module 3 includes a data uploading module and an abnormality reporting module.

Among them, the data upload module corresponds to step S3 above. It is set to upload the data collected by the sensor node to the sink node for data verification to obtain the data set of the sink node, and then upload it to the regional server for data verification. After passing, the data set of the sink node is stored in the off-chain database of the regional server and encrypted, and the hash value of the data set of the sink node is calculated and written into the alliance chain as a proof. Wherein, the operations of data verification, hash value calculation, and writing to the blockchain all run in a trusted execution environment on the regional server, and the hardware level ensures that the code and data have not been tampered with. The trusted execution environment refers to the hardware-level security technology provided by the regional server processor, which can provide an isolated operating space for programs and data, and ensure the credibility of execution results.

The abnormality reporting module is connected to the data uploading module, which corresponds to step S31 above, and is set to write the information to the alliance chain if an abnormality is found during the data verification process of the data uploading module and transmit it to the entire network , For troubleshooting business processing.

As a result, the data of the wireless sensor network is encrypted and stored on the regional server, and the summary of the data is written into the alliance chain to maintain the data security and credibility of the distributed data storage. At the same time, in the process of data verification between the convergence node and the regional server, if an abnormal situation is found, the secure storage function module writes the abnormal information into the blockchain network and transmits it to the entire network for on-site inspection and survey by the maintenance department.

The data access control function module 4 corresponds to the step S4 mentioned above, and is configured to decrypt a shared data set in the off-chain database and calculate the hash value of the shared data set, and then compare the hash value with all the data. The certificate in step S3 is used to verify the correctness of the shared data set, and the uniform resource locator of the shared data set is returned to realize data sharing. Preferably, the data access control function module is a data sharing smart contract, and the data sharing scope, time limit and visitor identity can be preset by using the data sharing smart contract to achieve the purpose of maintaining data ownership. As a result, it is possible to share data with other alliance chain nodes with legal identities in the alliance chain.

The foregoing descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Various changes can be made to the foregoing embodiments of the present invention. That is to say, all simple and equivalent changes and modifications made in accordance with the claims of the present invention and the content of the description fall within the protection scope of the patent of the present invention. What is not described in detail in the present invention is conventional technical content.

Claims

A security management method for a sensor network based on distributed ledger technology, which is characterized in that it includes:

Step S1: Select a top-level server and multiple regional servers as alliance chain nodes to build the alliance chain, and store distributed ledgers on it;

Step S2: Generate a pair of asymmetric keys for each sensor node and sink node in the lower layer of the regional server, solidify the private key in the memory of the sink node and the sensor node, and write the public key and its address Enter into the alliance chain;

Step S3: The sensor node collects data, uploads the data collected by the sensor node to the sink node and obtains the data set of the sink node, and then uploads it to the regional server to verify its data. After the verification is passed, the data set of the sink node The data set is stored in the off-chain database of the regional server and encrypted, and the hash value of the data set of the sink node is calculated and written into the alliance chain as a proof;

Step S4: Decrypt a shared data set in the off-chain database and calculate the hash value of the shared data set, and then compare the hash value with the evidence in step S3 to verify the correctness of the shared data set, And return the uniform resource locator of the shared data set to realize data sharing.
The security management method of a sensor network based on distributed ledger technology according to claim 1, characterized in that it further comprises step S31: in the process of data verification in step S3, if an abnormality is found, the The exception information is written into the alliance chain.
The security management method of a sensor network based on distributed ledger technology according to claim 1, characterized in that, in the step S1, the alliance chain is divided into a plurality of different parameters according to the security services running on the alliance chain The independent side chain.
The security management method of a sensor network based on distributed ledger technology according to claim 1, characterized in that, in the step S1, the top-level server and the regional server are authorized to be selected as alliance chain nodes , Each alliance chain node adopts a consensus algorithm to realize the consensus of the distributed ledger.
The security management method of a sensor network based on distributed ledger technology according to claim 4, wherein the consensus algorithm is a lightweight algorithm.
The security management method of a sensor network based on distributed ledger technology according to claim 1, characterized in that, in the step S2, the writing the public key and its address into the consortium chain includes:

Step S21: The user uses the identity management smart contract to enter the public key and address of the sink node that is permitted to join in the sensor network, the sink node goes online and registers the identity with the regional server;

Step S22: Step S22: Each sink node reads its surrounding sensor nodes, and the sensor nodes wake up and access the sink node.
The security management method of a sensor network based on distributed ledger technology according to claim 6, characterized in that, in step S21, the registration identity comprises: the sink node first sends an encrypted registration request information to the regional server The encrypted request registration information is encrypted using the private key of the sink node as the message payload, and the hash value of the payload is signed, and the identity of the sender is verified. Then, the regional server according to the entered public key of the sink node, Verify the authenticity of the requested registration information, and complete the registration identity when the verification is passed;

In the step S22, the access to the sink node includes: the sensor node sends an encrypted identity verification request to the sink node, and the encryption method of the identity verification request is the same as the encryption method of the requested registration information; The node verifies the authenticity of the identity verification request, and enables the sensor node to access the sink node when the verification passes.
The security management method of a sensor network based on distributed ledger technology according to claim 1, characterized in that, in the step S3, the data verification of the sink node is used to verify the source of the data collected by the sensor node and After the verification is passed, the data set of the sink node is obtained by signing the digest of the data load with its own private key.
The security management method of a sensor network based on distributed ledger technology according to claim 1, characterized in that, in the step S3, the operations of data verification, hash value calculation and writing to the blockchain all run the In a trusted execution environment on the regional server.
The security management method of a sensor network based on distributed ledger technology according to claim 1, wherein the step S4 is implemented by a data sharing smart contract, and the scope, time limit and visitor identity of the data sharing It can be preset by using the data sharing smart contract.
A security system for a sensor network based on distributed ledger technology. The sensor network includes a bottom-up hierarchical structure of sensor nodes, aggregation nodes, regional servers, and top-level servers, and is characterized in that it includes an alliance chain ( 1) And the device trust transfer function module (2), the secure storage function module (3), and the data access control function module (4) deployed on the alliance chain (1);

The alliance chain includes alliance chain nodes and a blockchain network established between the alliance chain nodes, and the alliance chain nodes are selected top-level servers and regional servers;

The device trust transfer function module (2) includes an asymmetric key generator and an identity management smart contract. The asymmetric key generator is set to generate a pair of unique non-symmetric key generators for each sensor node and sink node in the lower layer of the regional server. A symmetric key, the identity management smart contract is set to write the public keys and addresses of the sink node and the sensor node into the alliance chain;

The safe storage function module (3) includes a data upload module, which is configured to upload the data collected by the sensor node to the sink node for data verification to obtain the data set of the sink node, and then upload it to the regional server for data verification. After the verification is passed, the data set of the sink node is stored in the off-chain database of the regional server and encrypted, and the hash value of the data set of the sink node is calculated and written into the alliance chain as a proof;

The data access control function module (4) is configured to decrypt a shared data set in the off-chain database and calculate the hash value of the shared data set, and then compare the hash value with the evidence in step S3 Verify the correctness of the shared data set, and return the uniform resource locator of the shared data set to realize data sharing.
The sensor network security system based on distributed ledger technology according to claim 11, characterized in that the security storage function module (3) further comprises an abnormality reporting module, which is set to perform data verification in the data upload module In the process, if an abnormality is found, the information will be written into the alliance chain.
The security system of a sensor network based on distributed ledger technology according to claim 11, characterized in that the alliance chain (1) is divided into a plurality of independent side chains with different parameters.
The sensor network security system based on distributed ledger technology according to claim 11, wherein the identity management smart contract includes a sink node identity registration module and a sensor node identity verification module, and the sink node identity registration module is set To enter into the sensor network the public key and address of the sink node that is permitted to join, and to make the sink node register its identity with the regional server when it goes online; the sensor node identity verification module is set to make each sink node read its Surrounding sensor nodes, and enable sensor nodes to access the sink node when they wake up.
The sensor network security system based on distributed ledger technology according to claim 14, wherein the sink node identity registration module is further configured to: make the sink node first send an encrypted registration request to the regional server The encrypted request registration information is encrypted with the private key of the sink node as the message payload, and the hash value of the payload is signed, and the identity of the sender is verified. The regional server verifies according to the entered public key of the sink node The authenticity of the requested registration information, and the registration identity is completed when the verification is passed;

The sink node identity registration module is further configured to: make the sensor node send an encrypted identity verification request to the sink node, the encryption method of the identity verification request is the same as the encryption method of the requested registration information, and the sink node verifies The authenticity of the identity verification request is described, and the sensor node is connected to the sink node when the verification is passed.