CN116011033A - Personal data transaction method and system based on blockchain - Google Patents

Abstract

The invention discloses a block chain-based personal data transaction method, which belongs to the fields of block chain, data transaction and data right confirmation; the method includes: the data holder encrypts the original data, obtains the encrypted data and uploads it to the data agent Node; data buyers upload data collection requirements to data proxy nodes; data proxy nodes generate candidate data lists, and send candidate data lists and data scores to data buyers; data buyers purchase data based on candidate data lists and data scores, Generate purchase information; data holders generate data set encryption keys based on purchase information; data buyers download original data according to data set encryption keys. The invention also discloses a blockchain-based personal data transaction system. The invention can guarantee the confidentiality of the data, the integrity of the data, the autonomy of the data transaction and the fairness of the data transaction.

Description

A blockchain-based personal data transaction method and system

technical field

The present invention relates to the fields of block chain, data transaction, data right confirmation, etc., and in particular to a method and system for personal data transaction based on block chain.

Background technique

Under the innovation of information technology and new industrial transformation, data has been listed as production factors like land, labor, capital, etc., and data is known as the "oil" in today's data economy era, just like oil in the industrialization era. With the development of society, data will also drive the development of the information and intelligence era, and play an increasingly important role in economic and social development; therefore, the commodity attribute of data is also becoming increasingly prominent.

With the popularization of the Internet, the amount of data generated by individuals is growing explosively, and the value of personal data is increasing. Many companies are collecting user data, storing massive amounts of data in centralized databases, and using these data to optimize AI algorithms. Tap potential users, analyze the user market, and improve the corresponding service quality to obtain relevant benefits. In addition, users are paying more and more attention to personal privacy and information security, and there are many hidden dangers in storing personal data on third-party platforms to achieve data sharing and transactions; such as loss of user information, privacy leaks, and the proliferation of false information. The trading platform is not completely credible, and data holders lack control over data trading rights. To sum up, in order to fundamentally solve these problems, it is urgent to use transformative technology to solve them, build a decentralized data trading platform, let users master the sovereignty of data, protect personal data privacy and realize data realization.

As personal data is a special trading commodity, there are many hidden dangers in storing personal data in third-party platforms to achieve data sharing and transactions. Such as: lack of transaction transparency, lack of control over data transactions, user data leakage, and the proliferation of false information.

Contents of the invention

The purpose of the present invention is to provide a block chain-based personal data transaction method and system that can ensure the confidentiality of data, the integrity of data, the autonomy of data transactions, and the fairness of data transactions.

In order to solve the above technical problems, the present invention provides a blockchain-based personal data transaction method, comprising the following steps:

The present invention provides a block chain-based personal data transaction method, comprising the following steps:

The data holder encrypts the original data, obtains the encrypted data and uploads it to the data proxy node;

Data buyers upload data collection requirements to data broker nodes;

The data proxy node generates a candidate data list according to the data collection requirements and encrypted data, and sends the candidate data list and data scoring to the data buyer;

Data buyers purchase data according to the candidate data list and data scoring, generate purchase information, and send it to the corresponding data holder through the data proxy node;

According to the purchase information, the data holder generates download information and sends it to the corresponding data purchaser through the data proxy node;

The data buyer downloads the encrypted data from the data proxy node according to the download information and decrypts it to obtain the original data.

Preferably, the data holder encrypts the original data, obtains the encrypted data and uploads it to the data proxy node, which specifically includes the following steps:

The data holder generates the data holder key Key _i , encrypts the original data through the data holder key Key _i , obtains encrypted data, and generates data summary information;

The data holder uploads the encrypted data and data summary information to the data broker node.

Preferably, the data summary information is:

是数据持有者提供的数据签名。Among them: DS is the data summary information, hash(D _i ) is the hash value of the original data, des is the information describing the data, ac _i is the account of the data holder, type is the data set type,

It is the data signature provided by the data holder.

Preferably, after the data holder uploads the encrypted data, the following steps are further included:

Perform security checks on encrypted data;

After the security check is passed, compare the hash value of the original data in the data summary information with the hash value of the existing data information on the data proxy node;

Refuse to upload encrypted data if the same data exists;

If the same data does not exist, the upload is successful, and then according to the corresponding encrypted data, a unique identifier DID _i and a storage certificate are generated.

Preferably, the proof of storage is:

是唯一标识DID_i的存储证明，hash(D_i)是原始数据的hash值，用于和数据集的摘要信息DS关联；

是使用数据代理节点的私钥对DID_i进行签名，

是数据集的访问位置；In the formula:

is the storage certificate that uniquely identifies DID _i , and hash(D _i ) is the hash value of the original data, which is used to associate with the summary information DS of the data set;

is to use the private key of the data proxy node to sign DID _i ,

is the access location of the dataset;

The data collection requirements are:

DR＝(type,num,cnum,des,ac _j ,dl,s,r)

In the formula: DR indicates the data collection requirement, type indicates the type of data to be collected, num indicates the amount of data required by the data buyer, cnum indicates the maximum number of candidates for this data collection, generally speaking cnum≥num, des indicates the use description, dl indicates the deadline for this data collection, ac _j is the account of the data buyer, s indicates the lowest data quality score, and r indicates that the data holder can get paid after the data collection is completed.

Preferably, the data proxy node generates a list of candidate data according to data collection requirements and encrypted data, and sends the list of candidate data and data scores to data buyers, specifically including the following steps:

The data proxy node sends the data collection request to the data holder;

According to the data collection requirements, the data holder decides whether to add the corresponding unique identifier DID _i and the storage certificate of the encrypted data to the candidate certificate data list;

After the candidate data list reaches the limited number or the specified time limit, the data proxy node obtains the corresponding data summary information and data scoring according to the unique identifier DID _i and the storage certificate in the candidate data list, and adds it to the candidate data summary list;

The data proxy node sends the candidate data summary list to the data buyer as the candidate data list.

Preferably, the data holder generates download information according to the purchase information and sends it to the corresponding data purchaser through the data proxy node, which specifically includes the following steps:

According to the purchase information, the data holder obtains the data holder's key Key _i as the data set encryption key

进行加密，得到加密后数据集加密密钥

以加密后数据集加密密钥

作为下载信息通过数据代理节点发送给数据购买者。The data holder encrypts the data set key according to the data purchaser public key PK _j in the purchase information

Encrypt to get the encrypted data set encryption key

Encryption key with encrypted data set

As download information, it is sent to the data buyer through the data proxy node.

Preferably, the data buyer downloads the encrypted data from the data proxy node according to the download information and decrypts it to obtain the original data, which specifically includes the following steps:

进行解密，得到数据集加密密钥

The data buyer encrypts the encrypted data set encryption key in the downloaded information through the data buyer's public key PK _j

Decrypt to get the data set encryption key

从数据代理节点下载相应的加密数据并进行解密，得到原始数据。The data buyer encrypts the key according to the data set

Download the corresponding encrypted data from the data proxy node and decrypt it to obtain the original data.

Preferably, the following steps are also included:

The data buyer evaluates the data quality of the purchased raw data, gets the data score and uploads it to the data proxy node.

The present invention also provides a blockchain-based personal data transaction system, including:

The data encryption upload module is used for the data holder to encrypt the original data, obtain the encrypted data and upload it to the data proxy node;

The demand upload module is used for data buyers to upload data collection demands to the data agent node;

The list generation module is used for the data proxy node to generate a candidate data list according to the data collection requirements and encrypted data, and send the candidate data list and data scoring to the data buyer;

The purchase module is used for data purchasers to purchase data according to the candidate data list and data scoring, generate purchase information, and send it to the corresponding data holder through the data proxy node;

The download information generation module is used for data holders to generate download information according to the purchase information and send it to the corresponding data purchaser through the data proxy node;

The download module is used for the data buyer to download encrypted data from the data agent node according to the download information and decrypt it to obtain the original data.

Compared with prior art, the beneficial effect of the present invention is:

The present invention aims to use block chain technology to construct a personal data transaction method:

1) To ensure the confidentiality of data. Except for data holders and data buyers, no one will have access to the original data.

2), to ensure the integrity of the data. Once the data holder submits the data set to the transaction system, the data will not be modified during the transaction.

3) Guarantee the autonomy of data transactions. The decision whether to trade with data buyers is already in the hands of data traders. Data holders need to understand the flow of their data.

4) To ensure the fairness of data transactions. Data holders may price data sets unreasonably, and should ensure that data sets with higher data quality can get more rewards.

5) Dishonest data holders may publish multiple data copies of redundant data or meaningless data sets to the data trading platform to obtain data rewards. The rights of data buyers need to be ensured.

6) Dishonest data purchases may avoid paying for data transactions, and data buyers may also resell data on trading platforms. Fully protect the rights and interests of data holders.

Description of drawings

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a block diagram of a block chain-based personal data transaction system of the present invention;

Fig. 2 is a schematic flow chart of a personal data transaction method based on blockchain in the present invention;

Fig. 3 is a schematic diagram of the data storage process.

Detailed ways

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar extensions without violating the connotation of the present invention, so the present invention is not limited by the specific implementations disclosed below.

Terms used in one or more embodiments of this specification are for the purpose of describing specific embodiments only, and are not intended to limit one or more embodiments of this specification. As used in one or more embodiments of this specification and the appended claims, the singular forms "a", "the", and "the" are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and/or" used in one or more embodiments of the present specification 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, etc. may be used to describe various information in one or more embodiments of the present specification, the information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, the first may also be referred to as the second, and similarly, the second may also be referred to as the first without departing from the scope of one or more embodiments of the present specification. Depending on the context, the word "if" as used herein may be interpreted as "at" or "when" or "in response to a determination."

Below in conjunction with accompanying drawing, the present invention is described in further detail:

The present invention provides a block chain-based personal data transaction method, comprising the following steps:

The data holder encrypts the original data, obtains the encrypted data and uploads it to the data proxy node;

Data buyers upload data collection requirements to data broker nodes;

The data proxy node generates a candidate data list according to the data collection requirements and encrypted data, and sends the candidate data list and data scoring to the data buyer;

Data buyers purchase data according to the candidate data list and data scoring, generate purchase information, and send it to the corresponding data holder through the data proxy node;

According to the purchase information, the data holder generates download information and sends it to the corresponding data purchaser through the data proxy node;

The data buyer downloads the encrypted data from the data proxy node according to the download information and decrypts it to obtain the original data.

Preferably, the data holder encrypts the original data, obtains the encrypted data and uploads it to the data proxy node, which specifically includes the following steps:

The data holder generates the data holder key Key _i , encrypts the original data through the data holder key Key _i , obtains encrypted data, and generates data summary information;

The data holder uploads the encrypted data and data summary information to the data broker node.

Preferably, the data summary information is:

是数据持有者提供的数据签名。Among them: DS is the data summary information, hash(D _i ) is the hash value of the original data, des is the information describing the data, ac _i is the account of the data holder, type is the data set type,

It is the data signature provided by the data holder.

Preferably, after the data holder uploads the encrypted data, the following steps are further included:

Perform security checks on encrypted data;

After the security check is passed, compare the hash value of the original data in the data summary information with the hash value of the existing data information on the data proxy node;

Refuse to upload encrypted data if the same data exists;

If the same data does not exist, the upload is successful, and then according to the corresponding encrypted data, a unique identifier DID _i and a storage certificate are generated.

Preferably, the proof of storage is:

是唯一标识DID_i的存储证明，hash(D_i)是原始数据的hash值，用于和数据集的摘要信息DS关联；

是使用数据代理节点的私钥对DID_i进行签名，

是数据集的访问位置；In the formula:

is the storage certificate that uniquely identifies DID _i , and hash(D _i ) is the hash value of the original data, which is used to associate with the summary information DS of the data set;

is to use the private key of the data proxy node to sign DID _i ,

is the access location of the dataset;

The data collection requirements are:

DR＝(type,num,cnum,des,ac _j ,dl,s,r)

In the formula: DR indicates the data collection requirement, type indicates the type of data to be collected, num indicates the amount of data required by the data buyer, cnum indicates the maximum number of candidates for this data collection, generally speaking cnum≥num, des indicates the use description, dl indicates the deadline for this data collection, ac _j is the account of the data buyer, s indicates the lowest data quality score, and r indicates that the data holder can get paid after the data collection is completed.

Preferably, the data proxy node generates a list of candidate data according to data collection requirements and encrypted data, and sends the list of candidate data and data scores to data buyers, specifically including the following steps:

The data proxy node sends the data collection request to the data holder;

According to the data collection requirements, the data holder decides whether to add the corresponding unique identifier DID _i and the storage certificate of the encrypted data to the candidate certificate data list;

After the candidate data list reaches the limited number or the specified time limit, the data proxy node obtains the corresponding data summary information and data scoring according to the unique identifier DID _i and the storage certificate in the candidate data list, and adds it to the candidate data summary list;

The data proxy node sends the candidate data summary list to the data buyer as the candidate data list.

Preferably, the data holder generates download information according to the purchase information and sends it to the corresponding data purchaser through the data proxy node, which specifically includes the following steps:

According to the purchase information, the data holder obtains the data holder's key Key _i as the data set encryption key

进行加密，得到加密后数据集加密密钥

以加密后数据集加密密钥

作为下载信息通过数据代理节点发送给数据购买者。The data holder encrypts the data set key according to the data purchaser public key PK _j in the purchase information

Encrypt to get the encrypted data set encryption key

Encryption key with encrypted data set

As download information, it is sent to the data buyer through the data proxy node.

Preferably, the data buyer downloads the encrypted data from the data proxy node according to the download information and decrypts it to obtain the original data, which specifically includes the following steps:

进行解密，得到数据集加密密钥

The data buyer encrypts the encrypted data set encryption key in the downloaded information through the data buyer's public key PK _j

Decrypt to get the data set encryption key

从数据代理节点下载相应的加密数据并进行解密，得到原始数据。The data buyer encrypts the key according to the data set

Download the corresponding encrypted data from the data proxy node and decrypt it to obtain the original data.

Preferably, the following steps are also included:

The data buyer evaluates the data quality of the purchased raw data, gets the data score and uploads it to the data proxy node.

The present invention also provides a blockchain-based personal data transaction system, including:

The data encryption upload module is used for the data holder to encrypt the original data, obtain the encrypted data and upload it to the data proxy node;

The demand upload module is used for data buyers to upload data collection demands to the data agent node;

The list generation module is used for the data proxy node to generate a candidate data list according to the data collection requirements and encrypted data, and send the candidate data list and data scoring to the data buyer;

The purchase module is used for data purchasers to purchase data according to the candidate data list and data scoring, generate purchase information, and send it to the corresponding data holder through the data proxy node;

The download information generation module is used for data holders to generate download information according to the purchase information and send it to the corresponding data purchaser through the data proxy node;

The download module is used for the data buyer to download encrypted data from the data agent node according to the download information and decrypt it to obtain the original data.

In order to better illustrate the technical effects of the present invention, the present invention provides the following specific examples to illustrate the above technical process:

Embodiment 1. Aiming at the problems existing in the traditional centralized data transaction platform, the present invention provides a method for personal data transaction based on blockchain. The transaction method mainly consists of four entities, as shown in Figure 1, including:

Data holders: Data holders can be individual users or organizations, and they can decide whether to sell the data they hold according to the data transaction needs of data buyers.

Data buyers: Data buyers can also be individual users or organizations. They can start smart contracts and obtain the data sets they need from data holders.

Data proxy node: The data proxy node is a node with computing and storage, mainly responsible for data storage, re-encrypting the data set of the data holder, verifying the data set and data transaction information, and adding the corresponding data information to the blockchain .

Key distribution center: Responsible for issuing certificates for data holders and data buyers.

The present invention divides the blockchain-based personal data transaction method into the following parts: registering and storing data, publishing data requirements, participating in data collection, data screening, quality scoring and reward distribution. The specific process interaction is shown in Figure 2:

1. Data holders and data buyers can obtain anonymous identities through the registration procedure provided by the system. Generate a pair of asymmetric keys (PK _i , SK _i ) by using the ECC algorithm, and apply for a certificate from the key issuing center, and then perform a hash operation on the data holder's public key PK _i to obtain the user's account ac _i , That is, ac _i =hash(PK _i ). This account will be used as an account to get paid for participating in data transactions in the future;

The public key is open to all users in the system, and there will be public key certificates of data holders and data buyers in the key distribution center during the user registration phase.

2. Before storing the personal data set, the data holder needs to generate a data holder key Key _i locally to encrypt the uploaded data to ensure the data security of the data holder. When uploading data, it is necessary to fill in the corresponding data summary information to describe the data, and use the private key SK _i of the data holder to sign the data set. The format of the data summary information required by the present invention is specifically as follows:

是数据持有者提供的数据签名。Where hash(D _i ) is the hash value of the original data, des is the information describing the data, ac _i is the account of the data holder, type is the type of data set,

It is the data signature provided by the data holder.

3. After the data proxy node receives the information uploaded by the data holder, as shown in Figure 3, it will first perform a security test to ensure that the data does not contain information that endangers the system. Then compare the hash(D _i ) with the existing data information on the blockchain. If the same data exists, it means that the same data already exists in the trading platform, and the data holder will be rejected for this data storage. request. In view of the fact that the current data is easy to copy and spread as a virtual asset, the data is easily copied and traded, causing great losses to the data holders. Therefore, this step of detection is very necessary. At the same time, while uploading data, the data holder pays a certain storage fee, which is related to the occupied storage space.

4. After the data comparison is passed, the data agent will generate a unique identifier DID _i for the received data set, and generate a storage certificate. The storage proof format that uniquely identifies DID _i is defined as follows:

是使用数据代理节点的私钥对DID_i进行签名，

是数据集访问地址。针对区块链上区块大小容量有限的问题，本发明只把数据的摘要信息和存储证明

上链储存，而对于原始的数据信息则存放在链下的数据库中。当数据被上链储存之后，数据持有者会收到唯一标识DID_i的存储证明

并在智能合约上注册自己的唯一标识DID_i，方可参与数据交易。hash(D _i ) is the hash value of the original data, which is used to associate with the summary information DS of the data set.

is to use the private key of the data proxy node to sign DID _i ,

is the data set access address. Aiming at the problem of limited block size and capacity on the block chain, the present invention only uses the summary information and storage certificate of the data

It is stored on the chain, and the original data information is stored in the database under the chain. When the data is stored on the chain, the data holder will receive a storage certificate that uniquely identifies DID _i

And register your own unique ID DID _i on the smart contract before you can participate in data transactions.

5. As a data buyer, the smart contract on the trading platform can publish its own data collection requirements to the data holders in the trading platform. The format of the data collection requirements required by the present invention is defined as follows:

DR＝(type,num,cnum,des,ac _j ,dl,s,r)

type indicates the type of data to be collected, num indicates the amount of data required by the data buyer, cnum indicates the maximum number of candidates for this data collection, generally speaking cnum≥num, des indicates the purpose description, and dl indicates the deadline for this data collection , ac _j is the account of the data buyer, s means the lowest data quality score, and r means that after the data collection is completed, the data holder can get paid.

6. When the data demand contract item of the data buyer is published on the data trading platform, the platform will push a message to the data holders in the platform, and inform them immediately. In addition, data holders can also perform data retrieval on the trading platform to browse the current unfinished data solicitation demand.

添加到数据购买者发布的数据需求合约项的候选数据标识列表中。7. Data holders can check the relevant data collection requirements DR _i , and can judge whether the data type type is in compliance, how many participation quotas are currently available, whether the data use des is acceptable, and whether it is still too late before the deadline dl, And many factors such as whether the r reward remuneration meets one's expectations and so on should be considered whether to sell one's own data. When the data holder decides to sell his own data set, he will send the unique identifier DID _i and storage certificate of the data to be sold

Added to the candidate data identification list of the data demand contract item released by the data buyer.

检索到存储在区块链上的相应数据摘要信息，将返回给数据购买者一个候选数据摘要列表。8. When the amount of data received by the candidate data identification list for a certain data collection requirement reaches the quantity limited by cnum, or reaches the time limit specified by dl. The smart contract will be based on the unique identifier DID _i in the candidate data identifier list and storage proof

After retrieving the corresponding data abstract information stored on the blockchain, a list of candidate data abstracts will be returned to the data buyer.

9. After the data buyer receives the data set summary list, they will check the relevant information of the data, mainly looking at the data summary and data evaluation. For data sets that have never participated in data transactions before, data buyers can decide whether to purchase this data by consulting the data summary information. For the data set with previous data score S(DID _i ), the data buyer can decide whether to buy this data according to the score.

10. When the data buyer determines the data to be purchased from the candidate data set, he will return the list of the data sets to be accessed to the data agent, requesting to consult the original data set information, and the data set access request is defined as:

request(datalist{DID _i ,ac _i })

(数据集加密密钥

即为数据持有者密钥Key_i)，之后用数据购买者公钥PK_j加密，将加密公钥

返回给数据代理。The datalist is the list of data that the data buyer requests to access. The data agent will arrange DID _i and send it to the corresponding data holder of ac _i . After the data holder receives the DID _i of the relevant data set, it will retrieve the relevant data set encryption key

(dataset encryption key

It is the data holder’s key Key _i ), and then encrypted with the data buyer’s public key PK _j , and the encrypted public key

Returned to the data agent.

When the data agent initiates a key authorization application to the data holder, it means that the data holder has participated in the data collection issued by a data buyer ac _{j and} has been hired, and the data holder can obtain the data from the public key certificate If the public key PK _j of the purchaser ac _j has expired, the public key certificate can also be obtained from the key distribution center.

数据购买者使用自己的私钥SK_j对

解密，得到对应数据集DID_i的数据集加密密钥

并在相应的数据集访问地址

下载加密数据，通过数据持有者的公钥PK_i进行解密，得到原始数据。期间保证数据代理不会访问到数据的明文，确保数据的机密性。11. The data agent summarizes the feedback from all data holders and delivers the aggregated information to the data buyers. Data buyers get data access lists

Data buyers use their own private key SK _j pair

Decrypt to get the data set encryption key corresponding to data set DID _i

And access the address in the corresponding dataset

Download the encrypted data and decrypt it with the data holder's public key PK _i to get the original data. During this period, it is guaranteed that the data agent will not access the plaintext of the data to ensure the confidentiality of the data.

12. When data buyers access and use the collected data, they need to evaluate the data quality of the received data. The data quality assessment will also be recorded on the blockchain to provide data reference for subsequent data buyers. Quality assessment mainly evaluates _data quality from three main aspects: data integrity S _{i ,} accuracy S _a , _and availability Su . S _u ) ∈ ((-s, s), (-s, s), (-s, s)), where s is the threshold for abnormal evaluation given by malicious data buyers. Therefore, the cumulative data score of a certain data set DID _i is:

S(DID _i ) is the mean of the accumulated data scores.

13. After the data buyer completes the scoring of the data set, the transaction contract will distribute rewards, and the purchased data set can be linked to the account address ac _i of the corresponding data holder through DID _i . The reward r prepaid by the data buyer in the data demand is distributed. The specific reward distribution calculation formula is defined as follows:

where N _i represents the amount of data submitted by the data holder.

A block chain-based personal data transaction method of the present invention can achieve the following advantages:

1. Before the data transaction, confirm the data rights of the data holder and generate the corresponding data storage certificate to prevent the data from being resold on the platform. Data storage needs to be encrypted to ensure that only the parties to the transaction can obtain the plaintext.

2. As the data holder who provides the data, he has the absolute right to know and control whether the data will be involved in the transaction. Data holders decide for themselves whether their data sets will be traded with those data buyers.

3. Data buyers are required to pay in advance when publishing data solicitation to ensure that data holders can get paid.

4. An optional purchase method is designed for data buyers, providing enough data options to ensure that data buyers can obtain data sets with better data quality.

5. Data buyers are required to evaluate the data quality of the received data and provide data reference for subsequent data buyers.

In the present invention, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present invention, however, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, in which computer-readable program codes are carried. Such propagated data signals may take many forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. . Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the foregoing.

In the several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the modules, modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units , modules or components may be combined or may be integrated into another device, or some features may be omitted, or not implemented.

The units may or may not be physically separated, and a component displayed as a unit may be one physical unit or multiple physical units, that is, it may be located in one place, or may be distributed to multiple different places. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

In particular, according to the disclosed embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product, which includes a computer program carried on a computer-readable medium, where the computer program includes program codes for executing the methods shown in the flowcharts. In such an embodiment, the computer program can be downloaded and installed from a network via the communication part, and/or installed from a removable medium. When the computer program is executed by a central processing unit (CPU), the above-mentioned functions defined in the method of the present invention are performed. It should be noted that the computer-readable medium mentioned above in the present invention may be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or device, or any combination thereof.

The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, program segment, or portion of code that contains one or more logical functions for implementing specified executable instructions. It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or they may sometimes be executed in the reverse order, depending upon the functionality involved. It should also be noted that each block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by a dedicated hardware-based system that performs the specified functions or operations , or may be implemented by a combination of dedicated hardware and computer instructions.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or replacements within the technical scope disclosed in the present invention shall be covered within the protection scope of the present invention . Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. A block chain-based personal data transaction method, characterized in that, comprising the following steps: The data holder encrypts the original data, obtains the encrypted data and uploads it to the data proxy node; Data buyers upload data collection requirements to data broker nodes; The data proxy node generates a candidate data list according to the data collection requirements and encrypted data, and sends the candidate data list and data scoring to the data buyer; Data buyers purchase data according to the candidate data list and data scoring, generate purchase information, and send it to the corresponding data holder through the data proxy node; According to the purchase information, the data holder generates download information and sends it to the corresponding data purchaser through the data proxy node; The data buyer downloads the encrypted data from the data proxy node according to the download information and decrypts it to obtain the original data. 2. The personal data transaction method based on blockchain according to claim 1, wherein the data holder encrypts the original data, obtains the encrypted data and uploads it to the data agent node, specifically comprising the following steps: The data holder generates the data holder key Key _i , encrypts the original data through the data holder key Key _i , obtains encrypted data, and generates data summary information; The data holder uploads the encrypted data and data summary information to the data broker node. 3. The personal data transaction method based on block chain according to claim 2, characterized in that: The data summary information is:

Among them: DS is the data summary information, hash(D _i ) is the hash value of the original data, des is the information describing the data, ac _i is the account of the data holder, type is the data set type,

It is the data signature provided by the data holder. 4. The personal data transaction method based on blockchain according to claim 3, characterized in that, after the data holder uploads the encrypted data, the following steps are further included: Perform security checks on encrypted data; After the security check is passed, compare the hash value of the original data in the data summary information with the hash value of the existing data information on the data proxy node; Refuse to upload encrypted data if the same data exists; If the same data does not exist, the upload is successful, and then according to the corresponding encrypted data, a unique identifier DID _i and a storage certificate are generated. 5. The personal data transaction method based on block chain according to claim 4, characterized in that: Said proof of storage is:

In the formula:

is the storage certificate that uniquely identifies DID _i , and hash(D _i ) is the hash value of the original data, which is used to associate with the summary information DS of the data set;

It is to use the private key of the data proxy node to sign the unique ID DID _i ,

is the data set access address. 6. The personal data transaction method based on blockchain according to claim 5, characterized in that: the data proxy node generates a candidate data list according to data collection requirements and encrypted data, and sends the candidate data list and data scoring to the data Buyers, specifically include the following steps: The data proxy node sends the data collection request to the data holder; According to the data collection requirements, the data holder decides whether to add the corresponding unique identifier DID _i and the storage certificate of the encrypted data to the candidate certificate data list; After the candidate data list reaches the limited number or the specified time limit, the data proxy node obtains the corresponding data summary information and data scoring according to the unique identifier DID _i and the storage certificate in the candidate data list, and adds it to the candidate data summary list; The data proxy node sends the candidate data summary list to the data buyer as the candidate data list. 7. The blockchain-based personal data transaction method according to claim 6, wherein the data holder generates download information according to the purchase information and sends it to the corresponding data buyer through the data proxy node, specifically including the following step: According to the purchase information, the data holder obtains the data holder's key Key _i as the data set encryption key

The data holder encrypts the data set key according to the data purchaser public key PK _j in the purchase information

Encrypt to get the encrypted data set encryption key

Encryption key with encrypted data set

As download information, it is sent to the data buyer through the data proxy node. 8. The personal data transaction method based on blockchain according to claim 7, wherein the data buyer downloads the encrypted data from the data agency node according to the download information and decrypts it to obtain the original data, which specifically includes the following steps: The data buyer encrypts the encrypted data set encryption key in the downloaded information through the data buyer's public key PK _j

Decrypt to get the data set encryption key

The data buyer encrypts the key according to the data set

Download the corresponding encrypted data from the data proxy node and decrypt it to obtain the original data. 9. The blockchain-based personal data transaction method according to claim 8, further comprising the following steps: The data buyer evaluates the data quality of the purchased raw data, gets the data score and uploads it to the data proxy node. 10. A blockchain-based personal data transaction system for realizing the personal data transaction method according to any one of claims 1-9, characterized in that it includes: The data encryption upload module is used for the data holder to encrypt the original data, obtain the encrypted data and upload it to the data proxy node; The demand upload module is used for data buyers to upload data collection demands to the data agent node; The list generation module is used for the data proxy node to generate a candidate data list according to the data collection requirements and encrypted data, and send the candidate data list and data scoring to the data buyer; The purchase module is used for data purchasers to purchase data according to the candidate data list and data scoring, generate purchase information, and send it to the corresponding data holder through the data proxy node; The download information generation module is used for data holders to generate download information according to the purchase information and send it to the corresponding data purchaser through the data proxy node; The download module is used for the data buyer to download encrypted data from the data agent node according to the download information and decrypt it to obtain the original data.

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