WO2021088548A1

WO2021088548A1 - Smart contract based privacy data query method and apparatus

Info

Publication number: WO2021088548A1
Application number: PCT/CN2020/116990
Authority: WO
Inventors: 刘琦; 闫莺
Original assignee: 蚂蚁区块链科技(上海)有限公司
Priority date: 2019-11-08
Filing date: 2020-09-23
Publication date: 2021-05-14
Also published as: CN110580262A; CN110580262B

Abstract

One or more embodiments of the present description provide a smart contract based privacy data query method and apparatus. The method is applied to a blockchain node, and comprises: when receiving a query transaction for target privacy data initiated by a query party, reading a transaction identifier of a historical transaction relevant to the target privacy data and contained in the query transaction; obtaining the historical transaction according to the transaction identifier, and based on the historical transaction, determining a service contract called by the historical transaction; executing authority control codes defined in the service contract to determine a query authority of the query party for the target privacy data; and when the determined query authority is query allowed, obtaining the decoded target privacy data for viewing by the query party, the target privacy data being read into a trusted execution environment for decoding.

Description

Method and device for querying private data based on smart contract

Technical field

One or more embodiments of this specification relate to the field of blockchain technology, and in particular to a method and device for querying private data based on smart contracts.

Background technique

Blockchain technology is built on a transmission network (such as a peer-to-peer network). The network nodes in the transmission network use chained data structures to verify and store data, and use distributed node consensus algorithms to generate and update data.

At present, the two biggest challenges in enterprise-level blockchain platform technology are privacy and performance. It is often difficult to solve these two challenges at the same time. Most of the solutions are to lose performance in exchange for privacy, or do not consider privacy to pursue performance. Common encryption technologies that solve privacy problems, such as Homomorphic encryption and Zero-knowledge proof, are highly complex, have poor versatility, and may also cause serious performance losses.

Trusted Execution Environment (TEE) is another way to solve privacy issues. TEE can play the role of a black box in the hardware. Neither the code executed in the TEE nor the data operating system layer can be peeped, and only the pre-defined interface in the code can operate on it. In terms of efficiency, due to the black box nature of TEE, plaintext data is calculated in TEE instead of complex cryptographic operations in homomorphic encryption. There is no loss of efficiency in the calculation process. Therefore, the combination with TEE can achieve less performance loss. Under the premise, the security and privacy of the blockchain are greatly improved. At present, the industry is very concerned about the TEE solution. Almost all mainstream chip and software alliances have their own TEE solutions, including TPM (Trusted Platform Module) in software and Intel SGX (Software Guard Extensions) in hardware. , Software Protection Extension), ARM Trustzone (trust zone) and AMD PSP (Platform Security Processor, platform security processor).

Summary of the invention

In view of this, one or more embodiments of this specification provide a method and device for querying private data based on smart contracts.

In order to achieve the above objectives, one or more embodiments of this specification provide technical solutions as follows: According to the first aspect of one or more embodiments of this specification, a method for querying private data based on smart contracts is proposed, which is applied to the blockchain Node; the method includes: when receiving a query transaction for target private data initiated by the querying party, reading the transaction identifier of the historical transaction related to the target private data contained in the query transaction; according to the transaction Identify the acquisition of the historical transaction, and determine the business contract invoked by the historical transaction based on the historical transaction; execute the authority control code defined in the business contract to determine the query authority of the querying party for the target private data When the determined query authority is allowed to query, the decrypted target private data is obtained for viewing by the querying party, and the target private data is read into the trusted execution environment for decryption.

According to the second aspect of one or more embodiments of this specification, a device for querying private data based on smart contracts is proposed, which is applied to a blockchain node; the device includes: a transaction reading unit, which is initiated by the querying party when received During the query transaction for target privacy data, read the transaction identifier of the historical transaction related to the target privacy data contained in the query transaction; the contract determination unit obtains the historical transaction according to the transaction identifier, and based on the transaction identifier The historical transaction determines the business contract invoked by the historical transaction; the authority query unit executes the authority control code defined in the business contract to determine the query authority of the query party for the target private data; a data acquisition unit, When the determined query authority is query permission, the decrypted target private data is obtained for viewing by the querying party, and the target private data is read into a trusted execution environment for decryption.

According to a third aspect of one or more embodiments of this specification, an electronic device is proposed, including: a processor; a memory for storing executable instructions of the processor; wherein the processor runs the executable instructions In order to realize the method for querying private data as described in any of the above embodiments.

According to the fourth aspect of one or more embodiments of this specification, a computer-readable storage medium is provided, which stores computer instructions, which when executed by a processor, implements the method described in any of the above-mentioned embodiments. step.

Description of the drawings

Fig. 1 is a schematic diagram of creating a smart contract according to an exemplary embodiment.

Fig. 2 is a schematic diagram of invoking a smart contract provided by an exemplary embodiment.

Fig. 3 is a schematic diagram of invoking a business contract provided by an exemplary embodiment.

Fig. 4 is a flowchart of a method for querying private data based on smart contracts according to an exemplary embodiment.

Fig. 5 is a flowchart of another method for querying private data based on smart contracts provided by an exemplary embodiment.

Fig. 6 is a schematic structural diagram of a device provided by an exemplary embodiment.

Fig. 7 is a block diagram of a device for querying private data based on smart contracts according to an exemplary embodiment.

Detailed ways

The exemplary embodiments will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings indicate the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with one or more embodiments of this specification. Rather, they are merely examples of devices and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

It should be noted that in other embodiments, the steps of the corresponding method are not necessarily executed in the order shown and described in this specification. In some other embodiments, the method may include more or fewer steps than described in this specification. In addition, a single step described in this specification may be decomposed into multiple steps for description in other embodiments; and multiple steps described in this specification may also be combined into a single step in other embodiments. description.

Block chains are generally divided into three types: Public Blockchain, Private Blockchain and Consortium Blockchain. In addition, there are many types of combinations, such as private chain + alliance chain, alliance chain + public chain and other different combinations. Among them, the most decentralized one is the public chain. The public chain is represented by Bitcoin and Ethereum. Participants who join the public chain can read the data records on the chain, participate in transactions, and compete for the accounting rights of new blocks. Moreover, each participant (ie, node) can freely join and exit the network, and perform related operations. The private chain is the opposite. The write permission of the network is controlled by an organization or institution, and the data read permission is regulated by the organization. In simple terms, the private chain can be a weakly centralized system with strict restrictions and few participating nodes. This type of blockchain is more suitable for internal use by specific institutions. Consortium chain is a block chain between public chain and private chain, which can realize "partial decentralization". Each node in the alliance chain usually has a corresponding entity or organization; participants are authorized to join the network and form a stakeholder alliance to jointly maintain the operation of the blockchain.

Whether it is a public chain, a private chain or a consortium chain, it is possible to provide the function of a smart contract. A smart contract on the blockchain is a contract that can be triggered and executed by a transaction on the blockchain system. Smart contracts can be defined in the form of codes.

Taking Ethereum as an example, it supports users to create and call some complex logic in the Ethereum network. This is the biggest challenge that distinguishes Ethereum from Bitcoin blockchain technology. The core of Ethereum as a programmable blockchain is the Ethereum Virtual Machine (EVM), and every Ethereum node can run EVM. EVM is a Turing complete virtual machine, which means that various complex logic can be implemented through it. Users who publish and call smart contracts in Ethereum run on the EVM. In fact, what the virtual machine directly runs is the virtual machine code (virtual machine bytecode, hereinafter referred to as "byte code"). The smart contract deployed on the blockchain can be in the form of bytecode.

For example, as shown in Figure 1, after Bob sends a transaction containing the information to create a smart contract to the Ethereum network, the EVM of node 1 can execute the transaction and generate a corresponding contract instance. The "0x6f8ae93..." in Figure 1 represents the address of this contract, the data field of the transaction can be stored in bytecode, and the to field of the transaction is empty. After the nodes reach an agreement through the consensus mechanism, the contract is successfully created and can be called in the subsequent process. After the contract is created, a contract account corresponding to the smart contract appears on the blockchain and has a specific address, and the contract code will be stored in the contract account. The behavior of the smart contract is controlled by the contract code. In other words, smart contracts enable virtual accounts containing contract codes and account storage (Storage) to be generated on the blockchain.

As shown in Figure 2, still taking Ethereum as an example, after Bob sends a transaction for invoking a smart contract to the Ethereum network, the EVM of a certain node can execute the transaction and generate a corresponding contract instance. The from field of the transaction in Figure 2 is the address of the account of the transaction initiator (ie Bob), the "0x6f8ae93..." in the to field represents the address of the called smart contract, and the value field in Ethereum is the value of Ether , The method and parameters of calling the smart contract are stored in the data field of the transaction. The smart contract is executed independently on each node in the blockchain network in a prescribed manner. All execution records and data are stored on the blockchain. Therefore, when the transaction is completed, the blockchain will be stored on the blockchain that cannot be tampered with. Lost transaction certificate.

After the nodes in the blockchain network execute the transaction initiated by Bob, they will generate corresponding receipt data to record the receipt information related to the transaction. In this way, information about the execution result of the transaction can be obtained by querying the receipt of the transaction. Taking Ethereum as an example, the receipt data obtained by a node executing a transaction can include the following content: Result field, indicating the execution result of the transaction; Gas used field, indicating the gas value consumed by the transaction; Logs field, indicating the log generated by the transaction, and the log can be It further includes the From field, To field, Topic field, Log data field, etc. The From field represents the account address of the initiator of the call, the To field represents the account address of the called object (such as a smart contract), and the Topic field represents the subject of the log. The Log data field indicates log data; the Output field indicates the output of the transaction.

Generally, the receipt data generated after the transaction is executed is stored in plain text, and anyone can see the contents of the above-mentioned receipt fields contained in the receipt data, and there is no privacy protection setting and ability. In some solutions that combine blockchain and TEE, in order to achieve privacy protection, the entire content of the receipt data is stored on the blockchain as data that requires privacy protection. The block chain is a data set stored in a database of a node and organized by a specific logic. As described later, the physical carrier of the database may be a storage medium, such as a persistent storage medium. In fact, only part of the content of the receipt data may be sensitive, while other content is not sensitive. Only sensitive content needs to be protected for privacy, and other content can be disclosed. In some cases, it may even be necessary to perform retrieval of part of the content to drive The implementation of related operations, then the implementation of privacy protection for this part of the content will affect the implementation of retrieval operations.

The process of protecting user privacy can be shown in Figure 3: Step 302: User A creates a transaction for invoking a business contract, and sends the created transaction to the blockchain node.

User A can invoke the smart contract (ie, business contract) deployed on the blockchain by creating a transaction (including the account address of the called smart contract), so that the blockchain node executes the business contract to complete the corresponding business. For privacy protection, user A can use digital envelope encryption to encrypt the created transaction, which combines a symmetric encryption algorithm and an asymmetric encryption algorithm. Specifically, the transaction content is encrypted using a symmetric encryption algorithm (that is, the transaction content is encrypted using the symmetric key used by itself), and then the public key of the asymmetric encryption algorithm is used to encrypt the symmetric key.

Step 304, the blockchain node executes the business contract.

After receiving the encrypted transaction, the blockchain node reads the transaction into the TEE, first uses the private key of the asymmetric encryption algorithm to decrypt the symmetric key, and then uses the decrypted symmetric key to decrypt the transaction Obtain the transaction content, and then execute the business code of the business contract within the TEE.

In step 306, the blockchain node stores private data related to the transaction.

On the one hand, after receiving the transaction, the blockchain node (after passing the consensus) will publish the transaction (encrypted in the form of a digital envelope) to the blockchain for certification. On the other hand, after the blockchain node executes the transaction, it will also encrypt and store the relevant data obtained from the execution of the transaction (publish it on the blockchain for certification, or store it locally); among them, for the transaction corresponding to the transaction The receipt can be encrypted with the symmetric key used by user A, and the contract status data obtained in response to the execution of the business contract in response to the transaction can be encrypted with a specific symmetric key inside the TEE. In addition, data such as user A's account attribute information, business contract account attribute information, and business contract contract code can also be encrypted using a specific symmetric key inside the TEE. The data encrypted by these blockchain nodes above all belong to user A's private data on the blockchain.

In the above privacy protection scenario, the user may need to share the privacy data related to the business realized by the blockchain to some specific users for viewing, that is, these specific users can view the privacy related to the historical transactions initiated by the user. data. Then, the query authority can be set for the user's private data, so that other users who are allowed to query can view it. The following describes the private data query scheme of this specification in conjunction with FIG. 4.

Please refer to FIG. 4, which is a flowchart of a method for querying private data based on smart contracts according to an exemplary embodiment. As shown in FIG. 4, the method is applied to a blockchain node and may include the following steps 402 to 408.

Step 402: When receiving a query transaction for target privacy data initiated by the querying party, read the transaction identifier of the historical transaction related to the target privacy data included in the query transaction.

In this embodiment, the initiator invokes the business contract that has been deployed on the blockchain to execute the corresponding business code through the historical transaction, thereby completing the corresponding business. When developing the business contract, in addition to defining the business code corresponding to the business in the business contract, it is also necessary to define the authority control code of the privacy data related to the transaction that invokes the business contract in the business contract to determine Whether the inquirer of this private data is allowed to inquire. By defining the permission control code in the business contract, the private data can be associated with the permission control code that controls the query permission of the private data, so that each business contract can control the private data related to the transaction calling itself.

The development and deployment of business contracts can be completed by roles such as blockchain users, blockchain members, and blockchain administrators. Take the consortium chain as an example. Blockchain members (or blockchain users, administrators) with accounting authority set up authority control rules, and define the authority control rules in the form of authority control codes in the business contract (also Defined the business code). After completing the development of the business contract, the blockchain member can publish the business contract to the alliance chain through any node device in the alliance chain, and the business contract is specified by the member node device in the alliance chain. (For example, several authoritative node devices with accounting authority designated in the consortium chain) After completing the consensus, they are included in the distributed database (ie, distributed ledger) of the consortium chain. Based on the above method of deploying a business contract, the deploying party of the business contract (i.e., ordinary users or ordinary members with accounting authority) can control whether others are allowed to inquire about and send transactions to the business contract (that is, the transaction that calls the business contract). ) Related privacy data.

Among them, the consensus algorithms supported in the blockchain can include: the first type of consensus algorithm, that is, the consensus algorithm that node devices need to compete for the accounting right of each round of accounting cycle; for example, Proof of Work (POW) ), Proof of Stake (POS), Delegated Proof of Stake (DPOS) and other consensus algorithms; the second type of consensus algorithm, that is, pre-election of accounting nodes for each round of accounting cycle (no need to compete Accounting rights) consensus algorithms; for example, practical Byzantine Fault Tolerance (PBFT) and other consensus algorithms.

In the blockchain network using the first type of consensus algorithm, all node devices that compete for the right to bookkeeping can execute the transaction after receiving the transaction. Among the node devices competing for the right to bookkeeping, one node device may win this round of contention for the right to bookkeeping and become the bookkeeping node. The accounting node can package the received transaction with other transactions to generate the latest block, and send the generated latest block or the block header of the latest block to other node devices for consensus.

In the blockchain network using the second type of consensus algorithm, the node device with the right to book accounts has been agreed before this round of bookkeeping. Therefore, after the node device receives the transaction, if it is not the billing node of this round, it can send the transaction to the billing node. For this round of accounting nodes, the transaction can be executed during or before the process of packaging the transaction with other transactions to generate the latest block. After the accounting node generates the latest block, it can send the latest block or the block header of the latest block to other node devices for consensus.

As mentioned above, no matter which consensus algorithm shown above is adopted by the blockchain, the accounting node of this round can package the received transaction to generate the latest block, and the generated latest block or the latest block The header of the block is sent to other node devices for consensus verification. If other node devices receive the latest block or the block header of the latest block, and there is no problem after verification, the latest block can be appended to the end of the original blockchain to complete the accounting process of the blockchain. In the process of verifying the new block or block header sent by the accounting node, other nodes can also execute the transaction contained in the block.

Based on the above method of deploying business contracts for controlling query authority, each business contract only controls the query authority of private data related to the transaction that invokes itself. Therefore, when a user (as a query party) initiates a query transaction for target private data related to a historical transaction (initiated by any other user), the blockchain node needs to determine the business that controls the query authority of the target private data Contract, and then the business contract can be invoked to achieve permission control.

For blockchain nodes to call business contracts to achieve permission control, a distribution contract can be deployed on the blockchain in advance to identify whether the transaction received by the blockchain node is a query transaction, and when the received transaction is When querying a transaction, the corresponding business contract is further called to execute the authority control code (it can be understood as distributing the query transaction to the corresponding business contract). Specifically, the distribution code can be defined in the distribution contract, and the distribution code is used to call the business contract to execute the permission control code defined in the business contract. Therefore, the query transaction created by the querying party is a transaction for invoking the distribution contract. Then, when any transaction received by the blockchain node is used to call the distribution contract, any transaction can be used as a query transaction.

Step 404: Obtain the historical transaction according to the transaction identifier, and determine the business contract invoked by the historical transaction based on the historical transaction.

In this embodiment, the transaction identifier of the historical transaction can be obtained by offline sharing between the initiator and the inquiring party of the historical transaction, or by any other means. Taking Ethereum as an example, when a querying party creates a query transaction, it can record the hash value (as a transaction identifier) of the historical transaction notified by the initiator of the historical transaction in the data field of the query transaction. Then, when the blockchain node receives the query transaction, it can obtain the historical transaction stored on the blockchain through the hash value, and then according to the to field of the historical transaction (used to record the contract address of the called smart contract) Determine the business contract invoked by this historical transaction.

Step 406: Execute the authority control code defined in the business contract to determine the query authority for the target private data.

In this embodiment, after the blockchain node determines that the received transaction is a query transaction and determines the business contract called by the historical transaction, it calls the distribution contract to execute the distribution code defined in the distribution contract, thereby calling the determined business Contract execution authority control code.

Based on the role of the distribution contract as a "distribution query transaction", the distribution contract can be designed as a system-level smart contract. Therefore, the development and deployment of the distribution contract can be completed by the administrator of the blockchain. Also taking the alliance chain as an example, an administrator with management authority develops the distribution logic (calls the business contract based on the contract address of the business contract called by the historical transaction recorded in the query transaction), and distributes the logic in the form of code distribution Defined in the distribution contract. After completing the development of the distribution contract, the administrator can publish the distribution contract to the alliance chain for deployment (similar to the above-mentioned process of deploying smart contracts).

Among them, in one case, the distribution contract can be deployed through the genesis block of the blockchain, that is, the distribution contract is deployed when the blockchain is built, and the contract code of the distribution contract is recorded in the genesis block. In another case, the distribution contract can be deployed in the subsequent process of building the blockchain; for example, the administrator wants to increase the permission query function in the subsequent use process. Then, the administrator can initiate a transaction to create a distribution contract to deploy the distribution contract on the blockchain. Among them, the to field of the transaction is an empty string, and the binary code for initializing the contract is specified in the data field. When the contract is called later, the execution result of the code will be the contract code.

In the technical solution of this specification, in addition to the above-mentioned deployment of the distribution contract to call the business contract to achieve permission control, the above-mentioned distribution logic can also be solidified into the chain code in the form of distribution code, and released together with the chain code. The administrator needs to deploy later, and the contract code is solidified in the chain code, making the contract code controllable and effectively improving security. In other words, the operation of distributing the query transaction to the corresponding business contract is completed by the blockchain node itself, rather than by calling a smart contract.

It should be noted that the type of request initiated on the blockchain by a user who accesses the blockchain may specifically refer to a transaction used in a traditional blockchain. Of course, the type of request initiated on the blockchain by a user who accesses the blockchain can also be other than a transaction, other forms of instructions, messages, etc. with a standard data structure, one or more embodiments of this specification It is not particularly limited. In the following embodiments, the request initiated on the blockchain by the user accessing the blockchain is taken as an example for description.

In this embodiment, the permission control rules defined in the form of permission control codes in the business contract can be flexibly set according to actual needs; of course, one or more embodiments of this specification do not limit the specific content of the permission control rules. In one case, the identity information of the inquiring party can be used as the basis for authority control. Correspondingly, when the inquiring party creates the inquiry transaction, the inquiry transaction should contain the inquiring party's identity information. For example, the identity information of the inquiring party is the account ID (ie account address) of the inquiring party, and the account ID may be recorded in the from field of the inquiry transaction. Further, the permission control rule can be set to allow the querying party to query corresponding private data when the identity information of the querying party meets specific conditions. For example, when the inquiring party belongs to a pre-designated set of inquiring users, the inquiry authority of the inquiring party can be determined to allow the inquiry, or when the inquiring party's credit score exceeds the preset credit threshold, the inquiry authority of the inquiring party can be determined to be allowed Query and so on. Therefore, when determining the query authority of the querying party, the authority control code defined in the business contract can be executed to determine the querying party's query authority for the target private data according to the identity information of the querying party.

In another case, the identity information of the inquiring party and the identity information of the initiator of the historical transaction can be used together as the basis for permission control, then the permission control rules can be set as the identity information of the inquiring party and the identity of the initiator When the information meets specific conditions, the query party is allowed to query the corresponding private data. For example, the query group and the queried group are recorded in the permission control rules, and members belonging to the query group are allowed to view the private data of the members of the queried group; or, the permission control rules directly record the correspondence of which other users each user can view; or When the inquiry party and the initiator belong to the same team, the inquiry authority of the inquiry party can be determined to allow inquiry and so on. Therefore, when determining the query authority of the inquiring party, the identity information of the initiator of the historical transaction can be obtained based on the historical transaction, and then the authority control code defined in the business contract is executed, so as to be based on the identity information of the inquiring party and the identity of the initiator. The information determines the querying authority of the querying party for the target private data.

In another case, the identity information of the initiator of the historical transaction can be used as the basis for permission control. Then, the permission control rules can be set to allow the inquiring party to query the corresponding information when the initiator’s identity information meets specific conditions. Privacy data. For example, when the initiator belongs to a pre-designated set of users that can be queried, the query authority of the inquiring party can be determined to allow the query, or when the credit score of the initiator exceeds the preset credit threshold, the query authority of the inquiring party can be determined to be allowed Query and so on. Therefore, when determining the query authority of the inquirer, the identity information of the initiator of the historical transaction can be obtained based on the historical transaction, and then the authority control code defined in the business contract is executed to determine that the inquirer is targeting the target according to the identity information of the initiator. Query permissions for private data.

Step 408: When the determined query authority is allowed to query, obtain the decrypted target private data for viewing by the querying party, and the target private data is read into a trusted execution environment for decryption.

In this embodiment, for the above-mentioned protection of user privacy data, the privacy data is encrypted and stored. Therefore, when it is determined that the query authority of the querying party is allowed to query, the target private data is obtained and the obtained target private data is read into the trusted execution environment for decryption, so as to be obtained by the querying party. For example, the target privacy data can be obtained according to the transaction identification. Depending on the type of data contained in the target private data, the decryption method used is also different (because the encryption method is different).

When the target privacy data includes historical transactions and/or transaction receipts of historical transactions, it can be seen from the embodiment shown in Figure 3 that both historical transactions and transaction receipts of historical transactions are encrypted with the symmetric key used by the initiator of the historical transaction . Therefore, after obtaining the historical transaction and/or the transaction receipt of the historical transaction, the symmetric key used by the initiator (user A in the embodiment shown in FIG. 3) can be obtained first, and then the symmetric key can be passed in the TEE. The key decrypts historical transactions and/or transaction receipts of historical transactions. For the acquisition of the symmetric key used by the initiator, the symmetric key used to encrypt historical transactions can be obtained first (the symmetric key is encrypted by the public key used by the initiator, that is, the digital envelope is used in the embodiment shown in FIG. 3). Encryption), the symmetric key is decrypted in the TEE through the private key corresponding to the public key used by the initiator to obtain the decrypted symmetric key. It should be noted that, when the target privacy data is a historical transaction, the process of obtaining historical transactions and decrypting historical transactions is performed when step 404 is performed, that is, obtaining historical transactions according to the transaction identifier, and decrypting historical transactions to obtain plaintext transaction content, thereby Determine the business contract called by the historical transaction based on the content of the plaintext transaction. Therefore, when it is determined that the query permission is allowed to query, (no need to perform the operations of obtaining historical transactions and decrypting historical transactions) directly obtain the decrypted historical transactions for the querying party to view.

Among them, the symmetric key used by the initiator can be generated by the initiator through a symmetric encryption algorithm, or obtained through negotiation between the initiator and the blockchain node, or sent by the key management server. As for the symmetric encryption algorithm, for example, it may be the DES algorithm, the 3DES algorithm, the TDEA algorithm, the Blowfish algorithm, the RC5 algorithm, the IDEA algorithm, and so on. The public key used by the initiator is sent to the initiator by the key management server through remote certification, the TEE of the blockchain node is established by the SGX architecture, and the private key corresponding to the public key is sent to the blockchain by the key management server through remote certification Enclave of nodes (enclave, also called enclave). The asymmetric encryption algorithm used to generate the public key and the private key can be, for example, RSA, Elgamal, knapsack algorithm, Rabin, D-H, ECC (elliptic curve encryption algorithm), etc.

When the target privacy data includes at least one of the account attribute information of the initiator of the historical transaction, the account attribute information of the business contract, the contract code of the business contract, and the contract status data of the business contract, it can be seen from the embodiment shown in FIG. 3 that these Private data is encrypted with a specific symmetric key inside the TEE. Therefore, after obtaining these private data, the private data can be decrypted by the specific symmetric key of the blockchain node in the TEE. For the specific symmetric key inside the TEE, the SGX structure of the blockchain node is sent by the key management server after remote certification, or it is negotiated between the blockchain node and other blockchain nodes.

In this embodiment, similar to the above-mentioned way of encrypting historical transactions to protect privacy, when the querying party initiates a query transaction, it can also use the symmetric key used by itself to encrypt the created query transaction, and use its own symmetric key to encrypt the created query transaction. The public key encrypts the symmetric key. Therefore, after receiving the query transaction, the blockchain node first decrypts the symmetric key of the encrypted query transaction through the private key corresponding to the public key used by the querying party in the TEE, and then queries the transaction through the symmetric key pair obtained by decryption Decryption is performed to obtain the transaction content contained in the query transaction. After obtaining the target private data and decrypting the target private data, the blockchain node can encrypt the decrypted target private data with the symmetric key of the querying party, so that the querying party can use the symmetric key pair used by itself. The target private data is decrypted and viewed, thereby avoiding the target private data from being leaked.

Among them, the sources of the symmetric key, public key, and private key used for privacy protection of the query party are similar to those described above, and will not be repeated here. Of course, the asymmetric keys (public key and private key) used in this process can be the asymmetric keys used for the privacy protection of the initiator as described above.

In this embodiment, when it is determined that the inquiry authority of the inquiry party is to prohibit inquiry, a contract receipt indicating that the inquiry party prohibits inquiry of the target private data may be generated to be viewed by the inquiry party.

For ease of understanding, the following describes the process of the querying party viewing the target private data with reference to FIG. 5.

As shown in Figure 5, following the scenario of Figure 3 above, after user A initiates a transaction invoking the business contract, user A can share privacy data related to the transaction (in this scenario as a historical transaction) to user B, or User B has a need to view the private data. Then, the process of user B as the inquiring party inquiring the target private data may include the following steps.

In step 502, the user B creates a query transaction by using the client terminal.

In this embodiment, the to field of the query transaction records the contract address of the distribution contract, and the hash value (ie transaction ID) of the historical transaction can also be recorded in the data field (or other fields) of the query transaction. Among them, the hash value of historical transactions can be obtained by offline sharing between user B and user A, or obtained by any other means.

In step 504, the user B uses the digital envelope encryption to query the transaction through the client.

Step 506: User B initiates a query transaction to the blockchain node through the client.

In step 508, the blockchain node decrypts the query transaction in the TEE.

TEE is a secure extension based on CPU hardware and a trusted execution environment that is completely isolated from the outside. TEE was first proposed by Global Platform to solve the security isolation of resources on mobile devices, and parallel to the operating system to provide a trusted and secure execution environment for applications. ARM's Trust Zone technology is the first to realize the real commercial TEE technology. With the rapid development of the Internet, security requirements are getting higher and higher. Not only mobile devices, cloud devices, and data centers have put forward more demands on TEE. The concept of TEE has also been rapidly developed and expanded. Compared with the originally proposed concept, the TEE referred to now is a more generalized TEE. For example, server chip manufacturers Intel, AMD, etc. have successively introduced hardware-assisted TEE and enriched the concept and characteristics of TEE, which has been widely recognized in the industry. The TEE mentioned now usually refers more to this kind of hardware-assisted TEE technology. Different from the mobile terminal, cloud access requires remote access, and the end user is invisible to the hardware platform. Therefore, the first step in using TEE is to confirm the authenticity of TEE. Therefore, the current TEE technology has introduced a remote certification mechanism, which is endorsed by hardware manufacturers (mainly CPU manufacturers) and through digital signature technology to ensure that users can verify the state of the TEE. At the same time, security needs that can't be met by only secure resource isolation, further data privacy protection has also been proposed. Commercial TEEs including Intel SGX and AMD SEV also provide memory encryption technology to limit the trusted hardware to the CPU, and the data on the bus and memory are ciphertexts to prevent malicious users from snooping. For example, TEE technologies such as Intel’s Software Protection Extensions (SGX) isolate code execution, remote attestation, secure configuration, secure storage of data, and trusted paths for code execution. The applications running in TEE are protected by security and are almost impossible to be accessed by third parties.

Taking Intel SGX technology as an example, SGX provides a circle, that is, an encrypted trusted execution area in the memory, and the CPU protects data from being stolen. Take the SGX-supported CPU used by the blockchain node as an example. With the newly added processor instructions, a part of the area EPC (Enclave Page Cache, Enclave Page Cache, Enclave Page Cache) can be allocated in the memory through encryption in the CPU. The engine MEE (Memory Encryption Engine) encrypts the data in it. The encrypted content in EPC will be decrypted into plain text only after entering the CPU. Therefore, in SGX, users can distrust the operating system, VMM (Virtual Machine Monitor), and even BIOS (Basic Input Output System). They only need to trust the CPU to ensure that private data will not leakage.

In practical applications, the key of the asymmetric encryption algorithm can be generated by the key management server. Through remote certification, the key management server sends the private key to the blockchain node, specifically, it can be passed into the circle of the blockchain node. Blockchain nodes can contain multiple enclosures, and the above private key can be passed into the security enclosures in these enclosures; for example, the security enclosure can be a QE (Quoting Enclave) enclosure instead of AE (Application Enclave) ) Encircle the circle. For asymmetrically encrypted public keys, they can be sent by the key management server to the user's client. Then, the client can use the symmetric encryption algorithm to encrypt the created transaction, that is, use the symmetric key of the symmetric encryption algorithm to encrypt the transaction content, and use the asymmetric encryption algorithm to encrypt the symmetric key used in the symmetric encryption algorithm. Generally, the public key of the asymmetric encryption algorithm is used to encrypt the symmetric key used in the symmetric encryption algorithm. The above encryption method is called digital envelope encryption. After the blockchain node receives the encrypted transaction, it can first use the private key of the asymmetric encryption algorithm to decrypt, obtain the symmetric key of the symmetric encryption algorithm, and then use the symmetric encryption algorithm Decrypt the symmetric key to get the transaction content.

In step 510, the blockchain node determines that the received transaction is a query transaction for invoking the distribution contract.

In this embodiment, after receiving any transaction, the blockchain node reads the content of the to field of the transaction. When the content of the to field is the contract address of the distribution contract, it means that the transaction is used to call the distribution contract, and then it can be determined that the transaction is a query transaction.

Step 512: The blockchain node reads the hash value contained in the query transaction.

In step 514, the blockchain node obtains the from field and to field of the historical transaction according to the hsah value.

In this embodiment, the content of the from field of the historical transaction is the address of the initiator of the historical transaction (in this embodiment, the identity information of the initiator), and the content of the to field of the historical transaction is the contract of the business contract invoked by the historical transaction address.

In step 516, the blockchain node sends the from field and to field of the historical transaction to the distribution contract.

Step 518: The distribution contract determines the business contract invoked by the historical transaction according to the to field of the historical transaction.

Step 520, the distribution contract calls the business contract.

Step 522: The business contract determines the query authority of user B according to the from field of the query transaction and the from field of the historical transaction.

In this embodiment, the identity information of the inquiring party and the initiator of the historical transaction are jointly used as the basis for permission control as an example. For example, the permission control rules (defined in the business contract in the form of permission control codes) record the query group and the queried group, and members belonging to the query group are allowed to view the private data of the queried group members; or, directly record in the permission control rules Each user can view the corresponding relationship of which other users. Among them, the account address is used as the user's identity information. Then, the blockchain node executes the authority control code defined in the business contract to determine according to the account address of the querying party (the content of the from field of the query transaction) and the account address of the initiator of the historical transaction (the content of the from field of the historical transaction) User B's query authority.

Step 524: The business contract returns the query authority of user B to the blockchain node.

Step 526: When the query permission of user B is allowed to query, the blockchain node obtains the target private data.

In this embodiment, the blockchain node can obtain the target private data according to the hash value of the historical transaction. When the business contract is used to determine that user B's query authority is forbidden to query, a contract receipt regarding user B's forbidden to query the target private data can be generated for user B to view. Or, the blockchain node returns to user B a query-forbidden receipt to inform user B that the query permission is forbidden to query.

In step 528, the blockchain node reads the target privacy data into the TEE for decryption.

In this embodiment, it can be seen from the embodiment shown in FIG. 3 that, for the purpose of privacy protection, private data is encrypted and stored. At the same time, depending on the type of data contained in the private data, the encryption method used is also different. Therefore, after obtaining the target private data according to the hash value of the historical transaction, the obtained target private data is read into the trusted execution environment for decryption, so as to be obtained by the querying party.

When the target privacy data includes historical transactions and/or transaction receipts of historical transactions, it can be seen from the embodiment shown in Figure 3 that both historical transactions and transaction receipts of historical transactions are encrypted with the symmetric key used by the initiator of the historical transaction . Therefore, after obtaining the historical transaction and/or transaction receipt of the historical transaction, the symmetric key used by user A can be obtained first, and then the transaction receipt of the historical transaction and/or historical transaction can be decrypted by the symmetric key in the TEE . For the acquisition of the symmetric key used by the initiator, the symmetric key used to encrypt historical transactions (the symmetric key is encrypted by the public key used by user A) can be obtained first, and the public key used with user A can be used in the TEE The corresponding private key decrypts the symmetric key to obtain the decrypted symmetric key.

It should be noted that when the target privacy data is a historical transaction, the process of obtaining historical transactions and decrypting historical transactions is executed when step 514 is performed, that is, obtaining historical transactions according to the hash value of historical transactions, and decrypting historical transactions to obtain historical transactions The clear text transaction content of the transaction, so as to read the from field and to field of historical transactions. Therefore, in this case, when it is determined that the query permission is allowed to query, (no need to perform the operations of obtaining historical transactions and decrypting historical transactions) directly obtain the decrypted historical transactions for the querying party to view.

When the target privacy data includes at least one of user A's account attribute information, business contract account attribute information, business contract contract code, business contract contract status data, the specific symmetric key of the blockchain node can be passed in the TEE Decrypt these private data.

For example, the specific symmetric key can be a seal (Simple Encrypted Arithmetic Library) key, which can be sent to the blockchain node by the key management server after being remotely attested, or it can be between each blockchain node After negotiation, the blockchain node uses the seal key to encrypt and decrypt private data. Of course, after remote certification, the key management server sends the symmetric key to the blockchain node, or the symmetric key negotiated between the various blockchain nodes may not be the above-mentioned seal key, but the root key (root key). ), and the above-mentioned seal key may be a derived key of the root key. For example, the root key can irreversibly derive several versions of derived keys in turn, and any two adjacent keys can irreversibly derive a low version key from a higher version key, thereby forming a chained key Derivative structure. For example, if you need to derive 256 versions of keys with version numbers ranging from 0 to 255, you can use the root key and the version factor 0xFF (the decimal value is 255, that is, the version number of the key that needs to be generated; of course, You can also use other values) for hash calculation to obtain the key key-255 with the version number 255; by hashing the key key-255 and the version factor 0xFE, the key key- with the version number 254 is obtained. 254; ... By hashing the key key-1 and the version factor 0x00, the key key-0 with the version number of 0 is obtained. Due to the characteristics of the hash algorithm, the calculation between the high version key and the low version key is irreversible. For example, the key key-0 can be calculated from the key key-1 and the version factor 0x00, but the key cannot be passed through the key. -0 and version factor 0x00 deduces the key key-1.

Then, a certain version of the derived key can be designated as the above-mentioned seal key to encrypt private data. Further, the seal key can also be version updated, and based on the above-mentioned features, it should be updated from the lower version key to the higher version key, so that even if the lower version key is leaked, the higher version key cannot be reversed. Version key to ensure sufficient data security.

In step 530, the blockchain node uses the user B's symmetric key to encrypt the target private data.

Step 532: User B views the target privacy data.

In one embodiment, after the blockchain node encrypts the target private data, it can generate an event containing the target private data and store it in the blockchain log. Then, user B can use the client to call back through the blockchain Mechanism to obtain the event, so as to view the target privacy data. After obtaining the target private data, user B uses the symmetric key used by the client to decrypt the target private data to obtain the private data of the plaintext content.

In another embodiment, after the blockchain node encrypts the target private data, it can directly return the encrypted target private data to the client used by the user B. In the same way, user B uses the symmetric key used by the client to decrypt the target private data to obtain the private data of the plaintext content.

It can be seen that through the private data query scheme of this manual, user A does not need to share the symmetric key used by himself with user B, and can realize the sharing of private data between user A and user B, thereby improving security and convenience.

Corresponding to the above method embodiment, this specification also provides an embodiment of a private data query device based on a smart contract.

The embodiment of the privacy data query device based on smart contract in this specification can be applied to electronic equipment. The device embodiments can be implemented by software, or can be implemented by hardware or a combination of software and hardware. Taking software implementation as an example, as a logical device, it is formed by reading the corresponding computer program instructions in the non-volatile memory into the memory through the processor of the electronic device where it is located.

From a hardware perspective, please refer to FIG. 6, which is a schematic structural diagram of a device provided by an exemplary embodiment. As shown in FIG. 6, at the hardware level, the device includes a processor 602, an internal bus 604, a network interface 606, a memory 608, and a non-volatile memory 610. Of course, it may also include hardware required for other services. The processor 602 reads the corresponding computer program from the non-volatile memory 610 to the memory 608 and then runs it to form a smart contract-based privacy data query device at the logical level. Of course, in addition to the software implementation, one or more embodiments of this specification do not exclude other implementations, such as logic devices or a combination of software and hardware, etc. That is to say, the execution subject of the following processing flow is not limited to each The logic unit can also be a hardware or a logic device.

Please refer to FIG. 7. In the software implementation, the query device is applied to a blockchain node and may include the following units.

The transaction reading unit 701, when receiving a query transaction for target private data initiated by the querying party, reads the transaction identifier of the historical transaction related to the target private data included in the query transaction.

The contract determining unit 702 obtains the historical transaction according to the transaction identifier, and determines the business contract invoked by the historical transaction based on the historical transaction

The authority query unit 703 executes the authority control code defined in the business contract to determine the query authority of the query party for the target private data.

The data obtaining unit 704 obtains the decrypted target private data for viewing by the inquiring party when the determined query authority is allowed to query, and the target private data is read into the trusted execution environment for decryption.

Optionally, when any transaction received is used to invoke a distribution contract, the any transaction is regarded as the query transaction; the device further includes: a contract invocation unit 705, which executes the distribution defined in the distribution contract Code to call the business contract to execute the permission control code.

Optionally, the target privacy data includes at least one of the following: the historical transaction, a transaction receipt corresponding to the historical transaction, the account attribute information of the initiator of the historical transaction, and the account attribute information of the business contract , The contract code of the business contract, and the contract status data of the business contract.

Optionally, the target privacy data includes the historical transaction and/or the transaction receipt; the target privacy data is decrypted in the following manner: the symmetric key used by the initiator is obtained; The target private data is decrypted by the symmetric key in the execution environment.

Optionally, the data obtaining unit 704 is further configured to: obtain a symmetric key used to encrypt the historical transaction, the symmetric key being encrypted by the public key used by the initiator; in the trusted execution environment The private key corresponding to the public key used by the initiator is used to decrypt the symmetric key to obtain the decrypted symmetric key.

Optionally, the public key used by the initiator is sent to the initiator by the key management server through remote certification, and the trusted execution environment of the blockchain node is established by the SGX architecture, and corresponds to the public key The private key is sent to the circle of blockchain nodes by the key management server through remote certification.

Optionally, the target privacy data includes at least one of account attribute information of the initiator of the historical transaction, account attribute information of the business contract, contract code of the business contract, and contract status data of the business contract 1. Decrypt the target privacy data in the following ways:

The target private data is decrypted through the specific symmetric key of the blockchain node in the trusted execution environment.

Optionally, the trusted execution environment of the blockchain node is established by the SGX architecture, and the specific symmetric key is sent by the key management server after the SGX architecture of the blockchain node is remotely certified, or is It is obtained through negotiation between the blockchain node and other blockchain nodes.

Optionally, the authority query unit 703 is specifically configured to execute the authority control code defined in the business contract to determine the query authority of the query party for the target private data according to the identity information of the query party; Alternatively, the device further includes: an identity obtaining unit 706, which obtains the identity information of the initiator of the historical transaction based on the historical transaction; the authority query unit 703 is specifically configured to: execute the authority control defined in the business contract Code to determine the query authority of the query party for the target private data according to the identity information of the query party and the identity information of the initiator; or, execute the authority control code defined in the business contract to The identity information of the initiator determines the query authority of the querying party for the target private data.

Optionally, the symmetric key used to encrypt the query transaction is encrypted by the public key used by the query party.

After receiving the query transaction, the device further includes: a transaction decryption unit 707, which encrypts the symmetry of the query transaction in the trusted execution environment through a private key corresponding to the public key used by the query party Key decryption: decrypt the query transaction using the symmetric key obtained by decryption to obtain the transaction content contained in the query transaction; after decrypting the target private data, the device further includes: a data encryption unit 708, The decrypted target private data is encrypted by the symmetric key of the inquiring party.

Optionally, it further includes: a privacy processing unit 709, when the determined query authority is query prohibition, generate a contract receipt indicating that the query party prohibits querying the target private data for viewing by the query party.

The systems, devices, modules, or units explained in the above embodiments may be implemented by computer chips or entities, or implemented by products with certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cell phone, a camera phone, a smart phone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or Any combination of these devices.

For the convenience of description, when describing the above device, the functions are divided into various units and described separately. Of course, when implementing this specification, the functions of each unit can be implemented in one or more software and/or hardware.

Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

The present invention is described with reference to flowcharts and/or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are generated It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

This specification may be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. This specification can also be practiced in distributed computing environments. In these distributed computing environments, tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram. In a typical configuration, the computer includes one or more processors (CPU), input/output interfaces, network interfaces, and memory.

The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash memory (flash RAM). Memory is an example of computer readable media.

Computer-readable media include permanent and non-permanent, removable and non-removable media, and information storage can be realized by any method or technology. The information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, CD-ROM, digital versatile disc (DVD) or other optical storage, Magnetic cassettes, disk storage, quantum memory, graphene-based storage media or other magnetic storage devices or any other non-transmission media can be used to store information that can be accessed by computing devices. According to the definition in this article, computer-readable media does not include transitory media, such as modulated data signals and carrier waves.

It should also be noted that the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or equipment including a series of elements not only includes those elements, but also includes Other elements that are not explicitly listed, or they also include elements inherent to such processes, methods, commodities, or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, commodity, or equipment that includes the element.

The foregoing describes specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps described in the claims may be performed in a different order than in the embodiments and still achieve desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or sequential order shown in order to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

The terms used in one or more embodiments of this specification are only for the purpose of describing specific embodiments, and are not intended to limit one or more embodiments of this specification. The singular forms "a", "said" and "the" used in one or more embodiments of this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and/or" as used herein refers to and includes any or all possible combinations of one or more associated listed items.

It should be understood that, although the terms first, second, third, etc. may be used to describe various information in one or more embodiments of this specification, the information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of one or more embodiments of this specification, the first information may also be referred to as second information, and similarly, the second information may also be referred to as first information. Depending on the context, the word "if" as used herein can be interpreted as "when" or "when" or "in response to determination".

The foregoing descriptions are only preferred embodiments of one or more embodiments of this specification, and are not intended to limit one or more embodiments of this specification. All within the spirit and principle of one or more embodiments of this specification, Any modification, equivalent replacement, improvement, etc. made should be included in the protection scope of one or more embodiments of this specification.

Claims

A method for querying private data based on smart contracts, applied to a blockchain node, and the method includes:

When receiving a query transaction for target privacy data initiated by the querying party, read the transaction identifier of the historical transaction related to the target privacy data contained in the query transaction;

Acquiring the historical transaction according to the transaction identifier, and determining the business contract invoked by the historical transaction based on the historical transaction;

Execute the authority control code defined in the business contract to determine the query authority of the query party for the target private data;

When the determined query authority is query permission, the decrypted target private data is obtained for viewing by the querying party, and the target private data is read into a trusted execution environment for decryption.
The method according to claim 1, when any transaction received is used to invoke a distribution contract, the any transaction is regarded as the query transaction; the method further comprises:

Execute the distribution code defined in the distribution contract to call the business contract to execute the permission control code.
The method according to claim 1, wherein the target privacy data includes at least one of the following:

The historical transaction, the transaction receipt corresponding to the historical transaction, the account attribute information of the initiator of the historical transaction, the account attribute information of the business contract, the contract code of the business contract, the contract of the business contract Status data.
The method according to claim 3, wherein the target private data includes the historical transaction and/or the transaction receipt; the target private data is decrypted in the following manner:

Acquiring the symmetric key used by the initiator;

The target private data is decrypted through the symmetric key in the trusted execution environment.
The method according to claim 4, said obtaining the symmetric key used by the initiator comprises:

Obtaining a symmetric key used to encrypt the historical transaction, the symmetric key being encrypted by the public key used by the initiator;

In the trusted execution environment, the symmetric key is decrypted by the private key corresponding to the public key used by the initiator to obtain the decrypted symmetric key.
According to the method of claim 5, the public key used by the initiator is sent to the initiator by the key management server through remote certification, and the trusted execution environment of the blockchain node is established by the SGX architecture, and The private key corresponding to the public key is sent to the circle of blockchain nodes by the key management server through remote certification.
The method according to claim 1, wherein the target privacy data includes account attribute information of the initiator of the historical transaction, account attribute information of the business contract, contract code of the business contract, and contract of the business contract At least one of the status data; decrypt the target private data in the following manner:

The target private data is decrypted through the specific symmetric key of the blockchain node in the trusted execution environment.
According to the method of claim 7, the trusted execution environment of the blockchain node is established by the SGX architecture, and the specific symmetric key is certified by the key management server after the SGX architecture of the blockchain node is remotely certified Sent, or negotiated between the blockchain node and other blockchain nodes.
According to the method of claim 1,

The executing the authority control code defined in the business contract to determine the query authority for the target private data of the query party includes: executing the authority control code defined in the business contract to determine the authority control code defined in the business contract according to the query party The identity information of determines the query authority of the querying party for the target private data;

Alternatively, the method further includes: obtaining the identity information of the initiator of the historical transaction based on the historical transaction; and executing the authority control code defined in the business contract to determine that the inquiring party is directed to the target privacy The data query authority includes: executing the authority control code defined in the business contract to determine the query authority of the query party for the target private data according to the identity information of the query party and the identity information of the initiator Or, execute the authority control code defined in the business contract to determine the query authority of the query party for the target private data according to the identity information of the initiator.
The method according to claim 1, wherein the symmetric key used to encrypt the query transaction is encrypted by the public key used by the query party;

After receiving the query transaction, the method further includes: decrypting the symmetric key that encrypts the query transaction by using a private key corresponding to the public key used by the query party in the trusted execution environment, and The decrypted symmetric key decrypts the query transaction to obtain the transaction content included in the query transaction;

After decrypting the target private data, the method further includes: encrypting the decrypted target private data with the symmetric key of the querying party.
The method according to claim 1, further comprising:

When the determined query authority is query prohibition, a contract receipt indicating that the query party prohibits the query of the target private data is generated to be viewed by the query party.
A privacy data query device based on smart contract, applied to a blockchain node, and the device includes:

The transaction reading unit, when receiving a query transaction for target privacy data initiated by the querying party, reads the transaction identifier of the historical transaction related to the target privacy data contained in the query transaction;

A contract determining unit, acquiring the historical transaction according to the transaction identifier, and determining the business contract invoked by the historical transaction based on the historical transaction;

An authority query unit, which executes the authority control code defined in the business contract to determine the query authority of the query party for the target private data;

The data obtaining unit obtains the decrypted target private data for viewing by the inquiring party when the determined query authority is allowed to query, and the target private data is read into a trusted execution environment for decryption.
The device according to claim 12, when any transaction received is used to invoke a distribution contract, the any transaction is regarded as the query transaction; the device further comprises:

The contract calling unit executes the distribution code defined in the distribution contract to call the business contract to execute the permission control code.
The device according to claim 12, the target privacy data includes at least one of the following:

The historical transaction, the transaction receipt corresponding to the historical transaction, the account attribute information of the initiator of the historical transaction, the account attribute information of the business contract, the contract code of the business contract, the contract of the business contract Status data.
The device according to claim 14, wherein the target privacy data includes the historical transaction and/or the transaction receipt; the target privacy data is decrypted in the following manner:

Acquiring the symmetric key used by the initiator;

The target private data is decrypted through the symmetric key in the trusted execution environment.
The device according to claim 15, obtaining the symmetric key used by the initiator in the following manner:

Obtaining a symmetric key used to encrypt the historical transaction, the symmetric key being encrypted by the public key used by the initiator;

In the trusted execution environment, the symmetric key is decrypted by the private key corresponding to the public key used by the initiator to obtain the decrypted symmetric key.
The device according to claim 16, wherein the public key used by the initiator is sent to the initiator by the key management server through remote certification, and the trusted execution environment of the blockchain node is established by the SGX architecture, and is The private key corresponding to the public key is sent to the circle of blockchain nodes by the key management server through remote certification.
The device according to claim 12, wherein the target privacy data includes account attribute information of the initiator of the historical transaction, account attribute information of the business contract, contract code of the business contract, and contract of the business contract At least one of the status data; decrypt the target private data in the following manner:

The target private data is decrypted through the specific symmetric key of the blockchain node in the trusted execution environment.
The device according to claim 18, wherein the trusted execution environment of the blockchain node is established by the SGX architecture, and the specific symmetric key is certified by the key management server after the SGX architecture of the blockchain node is remotely certified Sent, or negotiated between the blockchain node and other blockchain nodes.
The device according to claim 12,

The authority query unit is specifically configured to execute the authority control code defined in the business contract to determine the query authority of the query party for the target private data according to the identity information of the query party;

Alternatively, the device further includes: an identity obtaining unit, which obtains the identity information of the initiator of the historical transaction based on the historical transaction; the authority query unit is specifically configured to execute the authority control code defined in the business contract, To determine the query authority of the query party for the target private data according to the identity information of the query party and the identity information of the initiator; or execute the authority control code defined in the business contract to The identity information of the initiator determines the query authority of the querying party for the target private data.
The device according to claim 12, wherein the symmetric key used to encrypt the query transaction is encrypted by the public key used by the query party;

After receiving the query transaction, the device further includes: a transaction decryption unit, which encrypts the symmetric secret of the query transaction through a private key corresponding to the public key used by the query party in the trusted execution environment Key decryption, decrypt the query transaction using the symmetric key obtained by decryption, to obtain the transaction content contained in the query transaction;

After decrypting the target private data, the device further includes: a data encryption unit, which encrypts the decrypted target private data by the symmetric key of the querying party.
The device according to claim 12, further comprising:

The privacy processing unit, when the determined query authority is query prohibition, generates a contract receipt indicating that the query party prohibits querying the target private data for viewing by the query party.
An electronic device including:

processor;

A memory for storing processor executable instructions;

Wherein, the processor implements the method according to any one of claims 1-11 by running the executable instruction.
A computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implements the steps of the method according to any one of claims 1-11.