Power blockchain system based on trusted computing

Abstract

The present invention relates to the technical field of trusted authentication, and provides an electric power blockchain system based on trusted computing, including an authorization service chain, a log service chain, and a remote proof chain; a trusted chip is provided in the blockchain nodes of the authorization service chain, the log service chain, and the remote proof chain; the log service chain measures the reputation value of the acquisition layer terminal in real time through a malicious node detection mechanism based on a smart contract, promptly discovers the terminal and removes it from the network, and prevents the malicious terminal from publishing malicious data; the log service chain and the remote verification chain perform remote integrity verification on the terminal requesting access to the system through a trusted chip; the authorization service chain performs policy verification on the terminal requesting access to the system. The system detects the access rights of the visitor through integrity proof and access policy verification, ensures the credibility of the access terminal, comprehensively maintains the safe and reliable operation of the electric power blockchain system, and protects the privacy data in the electric power blockchain.

Description

Technical Field

[0001] The present invention relates to the field of trusted authentication technology, and in particular to a power blockchain system based on trusted computing. Background Art

[0002] The decentralized technology of blockchain provides a reliable solution to the problems of massive data and high concurrency in the power Internet of Things. However, since blockchain mostly runs in an open and transparent environment, it is vulnerable to malicious attacks, leading to the leakage of sensitive data.

[0003] The Chinese patent with patent number 2019108105818 discloses a ubiquitous power Internet of Things data transmission system, and provides a power grid data transmission solution architecture that combines blockchain technology with edge computing technology. It can provide local network data transmission security for the ubiquitous power Internet of Things, that is, through blockchain technology, it effectively avoids the hidden dangers of data tampering during power grid communication transmission. Considering that the system architecture based on blockchain requires considerable computing power resources and storage resources, in order to better adapt to the decentralized design of the blockchain architecture and the computing power and storage resources required in the use of smart contract technology, an edge computing solution is also introduced to realize distributed computing and storage networks, reduce network congestion, accelerate network response, and enable more full utilization of resources and enhance the disaster recovery capability of the entire power communication network.

[0004] Although this solution eliminates the hidden dangers of centralization and reduces the risk of data tampering through blockchain, and edge computing technology reduces response delays, it does not take into account the security issues of access terminals and cannot determine in real time whether the terminal is trustworthy, posing serious security risks.

[0005] The Chinese patent with the patent number of 2019100116814 discloses a blockchain-based power Internet of Things terminal identity authentication method, which uses the decentralized characteristics of blockchain to improve the existing state of centralized data storage and centralized Internet of Things structure, reduces the excessive dependence of the power Internet of Things on the central structure, and prevents the entire power Internet of Things from being paralyzed due to damage to the central structure. Although the invention realizes a low-cost terminal access system for the power Internet of Things, the traditional blockchain consensus mechanism consumes a lot of time and computing power, and is not applicable in scenarios with high real-time requirements. At the same time, if the blockchain node works in an open network environment, if the blockchain node is maliciously attacked, it will bring serious privacy leakage problems.

[0006] The Chinese patent with the patent number of 2019112566060 discloses a method for lightweight identity authentication of perception terminals. The technical problem to be solved by this invention is to overcome the problem that the perception terminals of the power Internet of Things in the prior art have counterfeit access and the traditional PKI (public key infrastructure) authentication system is not applicable. Combined with the actual application of perception terminal access in the power Internet of Things business scenario, a method suitable for secure access of power perception terminals is designed, and a method for lightweight identity authentication of perception terminals of the power Internet of Things is provided. Although this invention realizes lightweight authentication based on a certain security level, there is a hidden danger of centralization in the edge authentication server. If the edge server is paralyzed or attacked by malicious visitors, the authentication system will be paralyzed.

[0007] Therefore, how to maintain the blockchain network environment and the security of private data in the blockchain while ensuring the efficiency of power blockchain services is an issue that technical personnel in this field urgently need to solve. Summary of the invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of insufficient security of the above-mentioned existing blockchain network environment and privacy data in the blockchain, and provide an electric power blockchain system based on trusted computing, which maintains the security of the blockchain network environment and privacy data in the blockchain while ensuring the efficiency of the electric power blockchain service.

[0009] To achieve the above-mentioned purpose, the present invention is implemented through the following technical solutions: an electric power blockchain system based on trusted computing, including an authorization service chain, a log service chain and a remote proof chain; a trusted chip is provided in the blockchain nodes of the authorization service chain, the log service chain and the remote proof chain; the log service chain detects the collection terminals in real time through a malicious node detection scheme based on a smart contract, and eliminates suspicious terminals with low credibility values; the authorization service chain can perform policy verification on terminals accessing the system; the remote verification chain can perform remote integrity verification on access terminals.

[0010] A further preferred solution of the present invention is: the terminal requesting access to the system is configured with a trusted chip, and the signature verification keys in the trusted chip of the terminal requesting access to the system are bound one by one to its trusted chip and stored in the remote certification chain; when the remote certification chain verifies the authenticity of the key, it issues a certificate to the terminal requesting access to the system.

[0011] A further preferred solution of the present invention is: when the system is initialized, the trusted chip will perform static integrity measurement on the system before all applications are run and generate an integrity value; when the system is running, the trusted chip will measure the integrity of the running status of each application and module, and store the generated integrity measurement value in the trusted register in the TPM, and record all steps in the integrity measurement process through log tracking.

[0012] A further preferred solution of the present invention is that the trusted chip contains a dedicated key pair for integrity message signature and signature verification for remote integrity certification; the process of remote integrity certification is as follows:

[0013] 1) The requester extracts the integrity measurement log information, signs it with the signature key, and provides the signed message to the verifier.

[0014] ISM=Sign Isk (M Log ,Pval)

[0015] The message is signed by ISM, Isk is the signature key, and M Log is a partial integrity message in the TPM log, Pval is the integrity measurement value of the requester; to ensure the real-time nature of the message, the requester needs to attach timestamp information, and the final message sent is {ISM, Ts};

[0016] 2) After receiving the message, the verifier first verifies the real-time nature of the message based on its own clock information. The system sets a timeout threshold T res , if T-Ts is satisfied <T res , then the verifier starts verification;

[0017] M Log ,Pval=Ver Ivk (ISM)

[0018] Where Ivk is the verification key; the verifier uses the integrity verification module-IVM to re-check the log message M of the log requester Log To verify integrity,

[0019] val′=IVM(M Log )

[0020] Compare Pval′ with the received Pval to see if they are consistent. If they are consistent, the verification succeeds, otherwise the verification fails.

[0021] A further preferred solution of the present invention is: the authorization service chain includes a trusted CA server, the log service chain includes a trusted server, and the remote certification chain includes a trusted verification server; each trusted server in the authorization service chain, the log service chain and the remote certification chain generates its own public and private key pair through a trusted chip using a symmetric encryption algorithm, and stores the public key information in the blockchain.

[0022] A further preferred solution of the present invention is that the authorization service chain randomly selects a node to generate a blockchain master key pair (ASC MPUK ,ASC MPrK ) and synchronized to the blockchain network;

[0023] The log service chain randomly selects a node to generate a blockchain master key pair (LSC MPUK ,LSC MPrK ) and synchronized to the blockchain network; the remote proof chain randomly selects a node to generate a blockchain master key pair (ROC MPUK ,ROC MPrK ) and synchronized to the blockchain network; the authorization service chain needs to set parameters L = (p, a, b, G, n) for the system to determine the elliptic curve E in the finite field GF (p) in order to systematically encrypt communication;

[0024] The authorization service chain negotiates a session key with the remote attestation chain and the log service chain.

[0025] A further preferred solution of the present invention is that the log service chain uses a malicious node detection method based on a smart contract to evaluate the credibility of the terminals at the collection layer in real time, and promptly checks the terminals with low credibility values ​​to maintain the credibility of the system operating environment.

[0026] A further preferred solution of the present invention is: the smart contract structure used in the malicious node detection method based on smart contracts is as follows:

[0027] SC-ASC=(LS, ES, Sen, θ, P, σ, Loc, Tim)

[0028] Among them, LS is the leader trusted server, responsible for issuing smart contracts; ES is the contract execution server, Sen is the collection terminal to be detected, and σ is the evaluation index (PLR, MDR, CDR, HBR T ), P is the reputation score, σ is the threshold, and Loc is the location of the node to be detected.

[0029] A further preferred embodiment of the present invention is as follows: the malicious node detection method based on smart contracts comprises:

[0030] Step 1: ES first checks the timestamp information of the message forwarded by the terminal to be detected to verify whether the message is outdated. If the message is outdated, the data packet is discarded;

[0031] The system records the timeout records of each node, and the system sets the threshold σ T , when the ratio of timeout messages of a node within a certain period of time exceeds the initial threshold σ T , then the node is directly judged as a malicious node;

[0032] Step 2: LS then detects the location information in the message. If the location information is seriously distorted, the current communication is directly judged as malicious communication, and the malicious data packet is recorded and discarded. The system also sets a threshold σ Loc , when the ratio of the node’s position distortion messages exceeds the initial threshold σ within a certain period of time Loc , then the node is directly judged as a malicious node;

[0033] Step 3: After verifying the timestamp information and location information, the system preliminarily determines that the current communication is normal. The system receives the data packet and evaluates the trustworthiness score of the current communication by calculating the packet loss rate, message delay rate, communication delay rate, and historical behavior.

[0034] Step 4: Eliminate terminals whose trustworthiness scores are lower than the threshold.

[0035] A further preferred solution of the present invention is: the calculation standard of the packet loss rate Packet Loss Rate is as follows:

[0036]

[0037] Where n recv is the number of successfully received data packets, n send For all packets sent in the current time interval;

[0038] The calculation standard of the message delay rate Message Delay Rate is as follows:

[0039] Malicious nodes will increase the delay when processing data. To ensure the real-time nature of the data, the system records the time taken by the current collection terminal from collecting data to forwarding data, and sets the time interval T d , calculate the message delay rate

[0040]

[0041] The calculation standard of the communication delay rate is as follows:

[0042] Malicious nodes have a longer response time than ordinary nodes. The system records the complete time from when the detected node receives the request to when the requester receives the response within a certain time interval. This delay is mainly for the message on the communication link.

[0043] CDR=(T hd +T td ) / T e

[0044] T td =Ms / Nb+pd / ts

[0045] Where T hd is the processing time, T td is the message propagation time, Ms is the current message size, Nb is the network bandwidth, pd is the propagation distance, ts is the propagation speed, and Te is the preset time interval;

[0046] The calculation criteria for the historical behavior are as follows:

[0047] Malicious nodes tend to communicate continuously within a certain interval. The system calculates the ratio of malicious information to normal information of the node to be detected within a certain time interval.

[0048] HBR T =Num MB / Num NB +Num MB

[0049] Where Num MB Indicates the number of malicious communications, Num NB is the number of normal communications, T is the set time interval;

[0050] The Communication Score (CS) of the node to be detected is:

[0051] CS=λ1*PLR+λ2*MDR+λ3*CDR+λ4HBR T

[0052] Satisfies λ1+λ2+λ3+λ4=1;

[0053] The system sets a threshold K. If CS≤K, the current communication is normal communication, otherwise it is malicious communication;

[0054] The total communication reputation of the node to be detected, P, is determined by the number of malicious communications of the node, N. MB And the normal communication times N NB Decide;

[0055]

[0056] The system sets a threshold σ. When P≤σ, the collection terminal is recorded as a malicious terminal.

[0057] LS uses a consensus mechanism to announce malicious node information to the entire network and kicks it out of the trusted network.

[0058] In summary, the present invention has the following beneficial effects: The present invention combines the characteristics of blockchain and power Internet of Things to propose a power blockchain security mechanism based on trusted computing. A trusted platform module (trusted chip) is introduced into the blockchain node server to ensure the trustworthiness of the server operating environment. An algorithm for real-time monitoring of malicious collection terminals based on credibility is designed at the collection layer to prevent malicious terminals from publishing malicious data. At the same time, the system detects the access rights of visitors through integrity proof and access policy verification, ensuring the trustworthiness of the access terminal, comprehensively maintaining the safe and reliable operation of the power blockchain system, and protecting the privacy data in the power blockchain. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a framework diagram of the power blockchain system based on trusted computing. DETAILED DESCRIPTION

[0060] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0061] This embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to this embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

[0062] like Figure 1 As shown, the present invention provides an electric power blockchain system based on trusted computing, and the overall architecture includes three blockchains: authorization service chain, log service chain and remote proof chain. A trusted chip is provided in the blockchain nodes of the authorization service chain, log service chain and remote proof chain, so that each node has strong identity authentication, and a trusted Internet of Things working environment is created through the trusted chip and malicious node detection. At the same time, the system requires that the user terminal connected to the network contains a trusted chip, and the visitor must undergo dual tests of access policy and integrity proof when accessing the network, which avoids malicious terminals from illegally accessing system resources and ensures the trustworthiness of the networked terminals.

[0063] Specifically, the log service chain measures the reputation of the collection layer terminals in real time through a malicious node detection mechanism based on smart contracts, promptly discovers the terminals and removes them from the network. The log service chain and the remote verification chain perform remote integrity verification on the terminals requesting access to the system through a trusted chip; the authorization service chain performs policy verification on the terminals accessing the system.

[0064] The trusted chip (TPM) integrates a variety of cryptographic algorithms and encapsulated keys, and can provide a variety of trusted computing functions, such as measuring platform integrity, verifying integrity information, encrypting sensitive messages, and signing. These functions can be implemented inside the TPM chip and separated from other parts of the system, so malicious code that tampers with the system cannot affect the execution environment inside the TPM.

[0065] TPM remote authentication: The system requires all terminals requesting access to the system to contain a TPM chip. The signature verification key in each TPM chip is bound to the TPM chip and stored in a trusted third party (remote attestation chain). The remote attestation chain can verify the authenticity of the key. Only when the signature verification key is authentic and exists in the TPM will the remote attestation chain issue a certificate for it.

[0066] The TPM integrity measurement process is as follows:

[0067] When the system is initialized, the TPM will perform static integrity measurement on the system before all applications are run and generate an integrity value. Then, when the application starts running, the integrity measurement program measures the running status of each application and module at the top, and stores the generated integrity measurement value in the trusted register (PCR) in the TPM. Since the PCR cannot be obtained from the outside, the integrity measurement value in the PCR can be considered safe to use.

[0068] To verify the integrity measurement value, the TPM records the PCR log, which tracks all the steps in the integrity measurement process. The verifier can quickly calculate the PCR value through the log and compare it with the original value to verify the legitimacy of the integrity proof process.

[0069] TPM can also provide remote integrity proof. TPM contains a dedicated key pair for integrity message signing and signature verification. These keys can be certified by the TPM authority. Since the keys are stored in hardware, the security of the key generation process is guaranteed. At the same time, external malicious users cannot steal private key information, preventing signature forgery.

[0070] The process of remote integrity proof is as follows:

[0071] 1) The requester extracts the integrity measurement log information, signs it with the signing key, and provides the signed message to the verifier.

[0072] ISM=Sign Isk (M Log ,Pval)

[0073] The message is signed by ISM, Isk is the signature key, and M Logis the partial integrity message in the TPM log, and Pval is the integrity measurement value of the requester. To ensure the real-time nature of the message, the requester needs to attach timestamp information, and the final message sent is {ISM, Ts}.

[0074] 2) After receiving the message, the verifier first verifies the real-time nature of the message based on its own clock information. The system sets a timeout threshold T res , if T-Ts is satisfied <T res , the verifier starts verification.

[0075] M Log ,Pval=Ver Ivk (ISM)

[0076] Where Ivk is the verification key. The verifier uses the integrity verification module (IVM) to re-verify the log requester's log message M Log Perform integrity verification.

[0077] Pval′=IVM(M Log )

[0078] Compare Pval′ with the received Pval to see if they are consistent. If they are consistent, the verification succeeds, otherwise the verification fails.

[0079] Before using the power blockchain system based on trusted computing provided by the present invention, the system is initialized. The system defaults to the ECC algorithm for symmetric encryption, the 128-bit AES algorithm for asymmetric encryption, and the 256-bit ECDSA algorithm for signature.

[0080] The system initialization steps are as follows:

[0081] 1) Each trusted server in the authorization service chain, log service chain and remote proof chain generates its own public and private key pair through a trusted chip and stores the public key information in the blockchain.

[0082] 2) The authorization service chain randomly selects a node to generate a blockchain master key pair (ASC MPUK ,ASC MPrK ) and synchronized to the blockchain network. The log service chain and remote proof chain generate key pairs in the same way. (LSC MPUK ,LSC MPrK , ROC MPUK ,ROC MPrK ).

[0083] 3) ASC needs to set parameters L = (p, a, b, G, n) for the system, which is used to determine the elliptic curve E in the finite field GF (p). It is used for systematic encrypted communication.

[0084] 4) ASC negotiates session keys with ROC and LSC.

[0085] Since symmetric encryption is much more efficient than asymmetric encryption, communication between blockchains uses symmetric encryption, which requires exchanging keys before communication.

[0086] The key negotiation process between ASC and LSC is as follows:

[0087] 1) The authorized service chain selects a leader node, and the leader node's TPM generates a random number A, a basic key (BasicKey), and a timestamp information package using a private key ASC MPrK After encryption, they are sent to LSC.

[0088] 2) After receiving the message, LSC uses the ASC public key to verify the validity of the message. After successful verification, the Basic Key and random number A are stored, and random number B is generated in the same way, and B is stored using the private key LSC. MPrK The encrypted data is sent to ASC.

[0089] 3) After receiving the LSC message, ASC uses the LSC public key LSC MPUK Decrypt the message to obtain the random number B, and use TPM to combine the random numbers A, B and BasicKey to generate the session key SK AL At the same time, the negotiation completion message is encrypted using the session key and sent to the LSC.

[0090] 4) LSC combines random numbers A, B and BasicKey using the same algorithm to generate the session key SK AL′ , after receiving the ASC message, use SK AL′ The message is decrypted. If the decryption is successful, the key negotiation is completed. The LSC feeds back to the ASC a message indicating that the session key negotiation is successful.

[0091] 5) After ASC receives the message, the negotiation is completed.

[0092] The negotiation process between ASC and ROC is consistent with the above process.

[0093] Before requesting to access the system, the (user) terminal needs to register. The terminal that the user uses to access the Internet of Things contains a TPM that can be verified in the remote proof chain. The TPM can provide functions such as secure storage, integrity measurement, and trusted cryptographic services.

[0094] 1) The user provides personal identification and TPM public key information (UTpm puk ) is encrypted with ASC and sent to ASC. ASC randomly elects a leader node to process the user request. ASC reviews the user information and sends a remote public key verification request to the trusted TPM verification third party after the review is successful.

[0095] 2) After receiving the verification request, ROC verifies whether the public key is credible and sends the result Res u Feedback to ASC. Use the master private key (R mprik ) is signed and sent to ASC. To verify the real-time nature of the message, a timestamp will be added to the message. The final message sent is Msg = {Sign roc ,Ts roc}, where Ts roc It is the timestamp information.

[0096] Res u =Ver TPM (UTpm puk )

[0097]

[0098] 3) After receiving the feedback result, ASC uses its own timestamp information Ts ASC Verify,the real-time nature of the received message and discard the message if it,times out.

[0099] ASC uses the ROC public key to verify the ROC signature. If the verification is successful, the user terminal's trusted TPM can be verified.

[0100]

[0101] 4) At this point, the system determines that the registered terminal is trustworthy, and the TPM chip in the leader node generates a random number A by combining the user identity information, and generates a trusted key based on this.

[0102] U pub ,U pri =Gen(A)

[0103] After generating the user key, the leader node generates a random integrity evidence (RIE) for the user to detect the integrity of the user's communication. The leader node uses its own private key (LN pri ) signature key and integrity evidence are published to the blockchain network.

[0104] 5) After receiving the signature message from the leader node, other nodes in the blockchain verify the authenticity of the signature. After a certain number of nodes have successfully verified the signature, the user key can be deemed valid.

[0105] 6) ASC sends the key information to the user through a secure channel.

[0106] The legitimate device owner can authorize other legitimate users, and ASC writes the authorization rules into the blockchain to provide LSC with legitimate access policy authentication.

[0107] In order to ensure the credibility of the operating environment of the power Internet of Things data collection equipment, the system uses a combination of hardware and software to maintain the equipment. LSC uses a malicious node detection technology based on smart contracts to conduct real-time terminal credibility assessment, promptly check for terminals with low credibility, and maintain the credibility of the system operating environment.

[0108] The structure of a smart contract is as follows:

[0109] SC-ASC=(LS, ES, Sen, θ, P, σ, Loc, Tim)

[0110] Among them, LS is the leader trusted server responsible for issuing smart contracts, ES is the contract execution server, Sen is the collection terminal to be detected, and σ is the evaluation index (PLR, MDR, CDR, HBR T ), P is the reputation score, σ is the threshold, and Loc is the location of the node to be detected.

[0111] The detailed process of malicious node detection is as follows:

[0112] ES first checks the timestamp information of the message forwarded by the terminal to be detected to verify whether the message is outdated. If the message is outdated, the data packet is discarded. The system records the timeout record of each node and sets the threshold σ T , when the ratio of timeout messages of a node within a certain period of time exceeds the initial threshold σ T , the node is directly judged as a malicious node. Then LS detects the location information in the message. If the location information is seriously distorted, the current communication is directly judged as malicious communication, and the malicious data packet is recorded and discarded. The system also sets the threshold σ Loc , when the ratio of the node’s position distortion messages exceeds the initial threshold σ within a certain period of time Loc , then the node is directly judged as a malicious node.

[0113] After verifying the timestamp information and location information, the system preliminarily determines that the current communication is normal communication. The system receives the data packet and calculates the credibility score value of the current communication.

[0114] The calculation criteria are as follows:

[0115] Packet Loss Rate: Since malicious nodes and unreliable links can increase the node packet loss rate, the packet loss rate can be used as one of the criteria for measuring malicious nodes.

[0116]

[0117] Where n recv is the number of successfully received data packets, n send All packets sent during the current time interval.

[0118] Message Delay Rate: Since malicious nodes will increase the delay when processing data, in order to ensure the real-time nature of the data, the system records the time taken by the current collection terminal from collecting data to forwarding data, and sets the time interval T d , calculate the message delay rate.

[0119]

[0120] Communication Delay Rate: Malicious nodes have a longer response time than ordinary nodes. The system records the complete time from when the detected node receives a request to when the requester receives a response within a certain time interval. This delay is mainly for messages on the communication link.

[0121] CDR=(T hd +T td ) / T e

[0122] T td =Ms / Nb+pd / ts

[0123] Where T hd is the processing time, T td is the message propagation time, Ms is the current message size, Nb is the network bandwidth, pd is the propagation distance, ts is the propagation speed, T e The preset time interval.

[0124] Historical behavior: Malicious nodes tend to communicate continuously within a certain interval. The system calculates the ratio of malicious information to normal information of the node to be detected within a certain time interval as one of the reference standards for the reputation value.

[0125] HBR T =Num MB / Num NB +Num MB

[0126] Where Num MB Indicates the number of malicious communications, Num NB is the number of normal communications, and T is the set time interval.

[0127] The current communication score (Communication Score, CS) of the node to be detected is:

[0128] CS=λ1*PLR+λ2*MDR+λ3*CDR+λ4HBR T

[0129] The ratio of each factor can be adjusted according to different scenarios, and must satisfy λ1+λ2+λ3+λ4=1.

[0130] The system sets a threshold K. If CS≤K, the current communication is normal communication, otherwise it is malicious communication.

[0131] The total communication reputation of the node to be detected, P, is determined by the number of malicious communications of the node (N MB ) and the number of normal communications (N NB )Decide

[0132]

[0133] The system sets a threshold σ. When P≤σ, the collection terminal is recorded as a malicious terminal. LS publishes malicious node information to the entire network through a consensus mechanism and kicks it out of the trusted network.

[0134] The Internet of Things has very high requirements for the real-time nature of messages. The traditional blockchain adopts the proof-of-work mechanism (PoW). Since the blockchain works in a completely open environment, the only way for an attacker to control the blockchain is to occupy more than 51% of the computing power of the entire network, and the cost of the attack is too high. However, the PoW mechanism consumes a lot of computing power and cannot meet the requirements in the power Internet of Things scenario. Since the server containing the TPM chip has a strong identity certificate that cannot be forged, the system has established a trusted verification chain (TVC) in the ASC that is specifically responsible for verification. Since each node in the TVC is highly trusted, the system can randomly assign accounting nodes without using the traditional consensus mechanism of proof of work, thereby improving the efficiency of system operation. The present invention designs a trusted verification mechanism based on a trusted server in the log recording chain, which is used to efficiently verify user access rights and improve the efficiency of system operation.

[0135] The system sets the parameter N, which is the number of trusted servers that need to participate in the verification. It can be adjusted according to different scenarios. In this paper, it is set to 12. To ensure the verification efficiency, the TVC stores the cache of the verification strategy in the ASC.

[0136] The process of TVC trusted verification is as follows:

[0137] 1) Randomly select a verification node from N nodes and establish communication with the visitor. Here, assume that node 1 is selected.

[0138] 2) Set the TVC accounting node at this time to node 2. Node 2 anonymizes the visitor's integrity information and verifies the authenticity of the integrity information with the ROC. If the ROC verification fails, the visitor's access request is rejected. If successful, proceed to step 3.

[0139] 3) Node 2 verifies whether the visitor's access policy and integrity evidence exist in the ASC cache. If the visitor's information does not exist in the cache, execute step 4. If it does, execute step 5.

[0140] 4) Node 2 requests ASC to update cache data. After the update is completed, it queries the blockchain again to see if there is any visitor information. If so, it executes step 5. If not, the visitor's access request is rejected.

[0141] 5) Node 2 verifies whether the integrity evidence in the blockchain is the same as the evidence provided by the visitor. If they are the same, it proves that the information has not been modified. Otherwise, the verification fails.

[0142] 6) Node 2 determines whether the visitor's access request meets the requirements based on the access policy in the ASC, and writes the judgment result into the blockchain system.

[0143] 7) Node 2 returns the verification result to the visitor and writes the verification process into the blockchain system for other verification nodes to check.

[0144] The power Internet of Things is the application of the Internet of Things in the smart grid. By interconnecting the data collection, authority control, and status monitoring of key links in the power grid system, such as power generation, transmission, transformation, distribution, and consumption, it realizes the interconnection of all things in each link of the power system and human-computer interaction, and forms an intelligent service system with the characteristics of comprehensive status perception, efficient information processing, and convenient and flexible application.

[0145] The data collected by various smart meters in ASC are stored in the ASC blockchain. The trusted server can verify the reputation value of each terminal in real time to prevent malicious terminals from uploading malicious data. The specific operation process of the trusted power Internet of Things system based on blockchain is as follows:

[0146] 1) If visitor A wants to access the data in the power Internet of Things, the visitor's trusted terminal collects its own integrity status information through the TPM integrity collection module, and encrypts the integrity status information, the resource information requested for access (Requ), and the integrity evidence (RIE) obtained during registration with the private key and sends them to TVC.

[0147] 2) TVC queries the visitor's public key information through the ASC cache and decrypts the visitor's request packet.

[0148] 3) TVC randomly selects nodes to perform access policy verification and integrity verification on the visitor through a trusted remote verification strategy to determine whether the access terminal is trustworthy and whether the access terminal has legal access rights to the requested data.

[0149] 4) If the verification is successful, LSC randomly selects a leader node to record the visitor's access behavior, obtains the power data information requested by the visitor in the blockchain, signs it with the blockchain private key, and then uses the visitor's public key to encrypt the message and signature and feed it back to the visitor.

[0150] 5) After receiving the message, the visitor uses his own private key to decrypt the message and uses the blockchain public key to verify the authenticity of the source of the message. If the verification is successful, it is considered successful.

[0151] The combination of blockchain and power Internet of Things greatly reduces the risk of central server paralysis under high concurrency conditions. At the same time, the system separates various permissions into different blockchains, solving the problem of over-centralization of policy decision-making in traditional Internet of Things systems and being more in line with the actual network operating environment.

Claims

1. The power blockchain system based on trusted computing includes an authorization service chain, a log service chain, and a remote proof chain; its characteristics are: A trusted chip is provided in the blockchain nodes of the authorization service chain, the log service chain, and the remote proof chain; The log service chain detects the collection terminals in real time through a malicious node detection solution based on smart contracts, and removes suspicious terminals with low credibility values; The authorization service chain can perform policy verification on terminals accessing the system; The remote attestation chain can perform remote integrity verification on the access terminal; When the system is initialized, the trusted chip will perform static integrity measurement on the system before all applications are run and generate an integrity value; When the system is running, the trusted chip measures the integrity of the operation of each application and module, and stores the generated integrity measurement value in the trusted register in the trusted chip, and records all steps in the integrity measurement process through log tracking; The trusted chip contains a dedicated key pair for integrity message signature and signature verification, which is used for remote integrity certification. The process of remote integrity certification is as follows: 1) The requester extracts the integrity measurement log information, signs it with the signing key, and provides the signed message to the verifier. Among them, ISM is the signed message, Isk is the signing key, is a partial integrity message in the trusted chip log, Pval is the integrity measurement value of the requester; to ensure the real-time nature of the message, the requester needs to attach timestamp information, and the final message sent is { ,Ts}; 2) After receiving the message, the verifier first verifies the real-time nature of the message based on its own clock information, and the system sets a timeout threshold , if satisfied , then the verifier starts verification; Among them, Ivk is the verification key; the verifier uses the integrity verification module-IVM to re-check the log message of the log requester To verify integrity, Compare With received Are they consistent? If they are consistent, the verification is successful, otherwise the verification fails; The log service chain uses a malicious node detection method based on smart contracts to evaluate the reputation of the terminals at the collection layer in real time, and promptly checks the terminals with low reputation values ​​to maintain the credibility of the system operating environment; The authorization service chain includes a trusted CA server, the log service chain includes a trusted server, and the remote proof chain includes a trusted verification server; each trusted server in the authorization service chain, the log service chain, and the remote proof chain generates its own public and private key pair using a symmetric encryption algorithm through a trusted chip, and stores the public key information in the blockchain; The authorization service chain randomly selects a node to generate a blockchain master key pair ( ) and synchronized to the blockchain network; The log service chain randomly selects a node to generate a blockchain master key pair And synchronize to the blockchain network; The remote proof chain randomly selects a node to generate a blockchain master key pair And synchronize to the blockchain network; The authorization service chain needs to set parameters L = (p, a, b, G, n) for the system to determine the elliptic curve E in the finite field GF (p) in order to systematically encrypt the communication; The authorization service chain negotiates a session key with the remote certification chain and the log service chain; The system sets the parameter N, where N is the number of trusted servers that need to participate in the verification. To ensure verification efficiency, the trusted verification chain stores the cache of the verification policy in the ASC. The trusted verification process of the trusted verification chain is as follows: Step 1), randomly select a verification node from N nodes and establish communication with the visitor. Here, we assume that node 1 is selected; Step 2), set the trusted verification chain accounting node at this time to node 2, node 2 anonymizes the visitor's integrity information and verifies the authenticity of the integrity information to ROC. If the ROC verification fails, the visitor's access request is rejected. If successful, continue to step 3; Step 3), Node 2 verifies whether the visitor's access policy and integrity evidence exist in the ASC cache. If the visitor's information does not exist in the cache, it executes step 4. If it does, it executes step 5. Step 4), Node 2 requests ASC to update cache data. After the update is completed, it queries ASC again to see if there is visitor information. If so, it executes step 5. If not, the visitor's access request is rejected. Step 5), Node 2 verifies whether the integrity evidence in the blockchain is the same as the evidence provided by the visitor. If they are the same, it proves that the information has not been modified, otherwise the verification fails; Step 6), Node 2 determines whether the visitor's access request meets the requirements based on the access policy in the ASC, and writes the judgment result into the blockchain system; Step 7), Node 2 returns the verification result to the visitor and writes the verification process into the blockchain system for other verification nodes to check.

2. The power blockchain system based on trusted computing according to claim 1 is characterized in that: The terminal requesting access to the system is configured with a trusted chip, and the signature verification keys in the trusted chip of the terminal requesting access to the system are bound one by one to its trusted chip and stored in the remote certification chain; when the remote certification chain verifies the authenticity of the key, it issues a certificate to the terminal requesting access to the system.

3. The power blockchain system based on trusted computing according to claim 1 is characterized in that: The smart contract structure used in the malicious node detection method based on smart contracts is as follows: SC-ASC=(LS,ES,Sen, ,P, ,Loc,Tim) Among them, LS is the leader trusted server, responsible for issuing smart contracts; ES is the contract execution server, and Sen is the collection terminal to be detected. is the evaluation index, P is the credit score, is the threshold, and Loc is the location of the node to be detected.

4. The power blockchain system based on trusted computing according to claim 3 is characterized in that: The malicious node detection method based on smart contracts includes: Step 1: ES first checks the timestamp information of the message forwarded by the terminal to be detected to verify whether the message is outdated. If the message is outdated, the data packet is discarded; The system records the timeout records of each node and sets the threshold , when the ratio of timeout messages of a node exceeds the initial threshold within a certain period of time , then the node is directly judged as a malicious node; Step 2: LS then detects the location information in the message. If the location information is seriously distorted, it directly determines that the current communication is malicious communication, records and discards the malicious data packet. The system also sets a threshold , when the ratio of the node's position distortion messages exceeds the initial threshold within a certain period of time , then the node is directly judged as a malicious node; Step 3: After verifying the timestamp information and location information, the system preliminarily determines that the current communication is normal. The system receives the data packet and evaluates the trustworthiness score of the current communication by calculating the packet loss rate, message delay rate, communication delay rate, and historical behavior. Step 4: Eliminate terminals whose trustworthiness scores are lower than the threshold.

5. The power blockchain system based on trusted computing according to claim 4 is characterized in that: The calculation standard of the packet loss rate Packet Loss Rate is as follows: in is the number of successfully received data packets, For all packets sent in the current time interval; The calculation standard of the message delay rate Message Delay Rate is as follows: Malicious nodes will increase the delay when processing data. To ensure the real-time nature of the data, the system records the time taken by the current collection terminal from collecting data to forwarding data, and sets the time interval T d, Calculating message delay rate The calculation standard of the communication delay rate is as follows: Malicious nodes have a longer response time than ordinary nodes. The system records the complete time from when the detected node receives the request to when the requester receives the response within a certain time interval. This delay is for messages on the communication link. in For processing time, is the message propagation time, Ms is the current message size, Nb is the network bandwidth, pd is the propagation distance, ts is the propagation speed, is a preset time interval; The calculation criteria for the historical behavior are as follows: Malicious nodes tend to communicate continuously within a certain interval. The system calculates the ratio of malicious information to normal information of the node to be detected within a certain time interval. in Indicates the number of malicious communications, is the number of normal communications, T is the set time interval; The Communication Score (CS) of the node to be detected is: satisfy ; The system sets a threshold K. If CS≤K, the current communication is normal communication, otherwise it is malicious communication; The total communication reputation P of the node to be detected is determined by the number of malicious communications of the node And the normal communication times Decide; System Setting Threshold , when P≤ When the collection terminal is detected, the terminal is recorded as a malicious terminal; LS uses a consensus mechanism to announce malicious node information to the entire network and kicks it out of the trusted network.

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