CN116633522A - Two-party privacy intersection method and system based on blockchain - Google Patents

Abstract

The application relates to a block chain-based two-party privacy intersection method and a system, wherein the method comprises the following steps: the server encrypts the own data by using a private key, and uploads the public key and the encrypted data to the blockchain so as to be convenient for sharing; the service side initiates an intelligent contract and signs an intelligent contract with the inquiring side and the arbitrating side; performing intersection calculation between the inquiring party and the service party, performing Hash calculation on the intermediate calculation result, and uploading the intermediate calculation result to a blockchain for certification; the inquiring party verifies the final calculation result, and confirms or applies arbitration to the arbitrating party according to whether the result is correct or not; the arbitrator verifies according to the certificate on the chain, judges whether the inquirer has fraudulent behaviors or not, and makes corresponding decisions; the inquiring party or the arbitrating party invokes the signed intelligent contract to carry out signature confirmation, thereby giving rewards to the service party or punishing the service party. Compared with the prior art, the application has the advantage of high safety.

Description

A blockchain-based two-party privacy seeking intersection method and system

technical field

The present invention relates to the fields of block chain and privacy computing, in particular to a method and system for seeking intersection of privacy between two parties based on block chain.

Background technique

In today's data sharing field, on the one hand, data holders are reluctant to share data, because the data needs to sign various contracts with relevant institutions before using the data, which not only has high operating costs, but also makes it difficult to sue malicious parties in the event of disputes. On the other hand, due to the current data security regulations, data holders are not sure about the security of the data during use, so they dare not share data easily.

However, the current security negotiation protocol mainly uses the cloud server as the third party to perform the negotiation on the encrypted sets of both parties. Although this improves the efficiency, its security depends heavily on the credibility of the third-party server. When the third-party When the server colludes with one of the parties, the information of the other parties can be easily leaked. At the same time, when the third-party server is attacked by DDoS, the entire system may be paralyzed, and the reliability is not high.

Contents of the invention

The purpose of the present invention is to provide a highly secure block chain-based two-party privacy interrogation method and system in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

According to a second aspect of the present invention, there is provided a blockchain-based two-party privacy seeking intersection method, the method comprising:

The service party encrypts its own data with a private key, and uploads the public key and encrypted data to the blockchain for easy sharing;

The service party initiates a smart contract and signs a smart contract with the query party and the arbitrator;

Intersection calculations are performed between the querying party and the server, and the intermediate calculation results are hashed and uploaded to the blockchain for storage;

The inquiring party verifies the final calculation result, confirms whether the result is correct or applies to the arbitrator for arbitration;

The arbitrator conducts verification based on the evidence stored on the chain, determines whether the inquiring party has committed fraud, and makes a corresponding ruling;

The inquiring party or the arbitrator invokes the signed smart contract for signature confirmation, thus rewarding or punishing the service party.

Preferably, the service party encrypts its own data with a private key, and uploads the public key and encrypted data to the blockchain for easy sharing, including:

Generate a key pair (E, D, N) using an encryption algorithm;

Use the private key (D, N) to encrypt the plaintext to obtain the ciphertext C1;

Upload the public key (E, N) and ciphertext C1 to the blockchain for disclosure.

Preferably, the encryption algorithm is RSA encryption algorithm.

Preferably, the service party initiates a smart contract and signs a smart contract with the query party and the arbitrator, including:

The service initiates a request to the blockchain and publishes a smart contract to the blockchain;

The arbitrator receives the blockchain notification and signs it after confirming that the contract is legal;

The inquiring party receives the block chain notification, and after verifying that the contract has been signed by the arbitrator, if it accepts the reward and punishment mechanism stipulated in the smart contract, it will sign on the smart contract.

Preferably, the intersecting calculation is performed between the querying party and the service party, and the intermediate calculation result is hash calculated and then uploaded to the block chain for depositing evidence, including:

The query party randomly selects a random number for each element in its own data set, encrypts the random number with the public key (E, N) of the server, and then multiplies it with the hash value of the corresponding element to obtain the blinded Data C_Enc, and then send the blinded data to the service party, and upload the blinded data to the blockchain platform for deposit after hash calculation;

The service party receives the blinded data sent by the query party, decrypts it with its own private key (D, N) to obtain the decrypted data C_Dec, then sends the decrypted data to the query party, and uploads the decrypted data to the block after hash calculation Chain platform for deposit certificate;

The inquiring party receives the decrypted data sent by the service party and divides it by the random number selected during the blinding process to obtain the unblinded data C2;

The query party downloads the encrypted data of the service party from the blockchain platform, and calculates the encrypted data provided by the service party and the unblinded data to obtain the intersection of the two parties.

Preferably, the inquiring party verifies the final calculation result, confirms whether the result is correct or applies to the arbitrator for arbitration, including:

The query party can encrypt the data decrypted by the service party again with the public key of the service party to obtain the data before the decryption by the service party, perform hash calculation on these data, and store the certificate with the previous one on the blockchain platform The inquiring party adds the blind data hash value to compare, and then it can be judged whether the server is calculating according to the agreement;

If the service party does not have fraudulent behavior, it will sign on the smart contract, and give corresponding rewards to the service party according to the provisions of the contract;

If the service provider is found to be fraudulent, it will apply to the arbitrator for arbitration and refuse to sign on the smart contract.

Preferably, the arbitrator conducts verification based on the evidence stored on the chain, determines whether the inquiring party has fraudulent behavior, and makes a corresponding ruling, including:

Compare the storage certificates on the blockchain during the calculation process of the service party and the query party on the blockchain:

If the service party does have fraudulent behavior, it will sign and confirm on the smart contract, and the service party will be punished according to the pre-signed smart contract, and the arbitrator can also choose to disclose the malicious behavior of the service party to the entire network;

If there is no fraudulent behavior by the service party, the smart contract will be signed, and the service party will be rewarded accordingly according to the provisions of the smart contract.

According to the second aspect of the present invention, a two-party privacy interrogation system based on blockchain is provided, which is characterized in that it includes a server, an inquiring party, an arbitrator, and a blockchain module. Ask for privacy.

According to a third aspect of the present invention, an electronic device is provided, including a memory and a processor, the memory stores a computer program, and the processor implements any one of the methods when executing the program.

According to a fourth aspect of the present invention, there is provided a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, any one of the methods described in the present invention is implemented.

Compared with the prior art, the present invention has the following advantages:

1) For the inquiring party, in the process of encrypting the server, since the set is encrypted with the server’s own private key, and the inquiring party only knows the public key of the server, since it is impossible to deduce from the public key Private key, so the query party cannot get the original data of the service party.

2) For the server, in the process of blinding the query, although the public key of the server is used for encryption, since the query multiplies a random number for each element, even if the server can use The private key is used to decrypt, and the obtained data will also contain random numbers randomly generated by the querying party, so the server cannot know the original data of the querying party.

3) If the service party does not abide by the implementation of the agreement, the query party can find out through comparison, and at the same time apply to the arbitrator for arbitration, and the arbitrator can trace back the evidence stored on the chain to verify whether the service party has maliciously violated the agreement , so as to ensure that the service party is rewarded or punished accordingly.

Description of drawings

Fig. 1 is the system structure schematic diagram in the embodiment;

Fig. 2 is a schematic diagram of the overall flow of a blockchain-based two-party privacy interrogation system provided by the embodiment;

Fig. 3 is a schematic flow diagram of a part of the intersection calculation process of a blockchain-based two-party privacy seeking intersection system provided by the embodiment;

FIG. 4 is a schematic flow diagram of a part of the intersection calculation process of a blockchain-based two-party privacy seeking intersection system provided by the embodiment;

Fig. 5 is a schematic flow diagram of a partial intersection calculation process of a blockchain-based two-party privacy seeking intersection system provided by an embodiment.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

Example

In order to better understand the present invention, the following first introduces the schematic structural diagram of the blockchain-based two-party privacy interrogation system provided by the embodiment of the present invention:

Fig. 1 is a schematic structural diagram of a blockchain-based two-party privacy seeking intersection system provided by an embodiment of the present invention. As shown in Fig. 1, nodes in the blockchain network structure are divided into three types, including server nodes, query party node and arbitrator node. The server node is the node that provides the data set, the query node is the node that needs to perform data query, and the arbitrator node is the node that handles the dispute between the server and the query party.

Intersection calculations can be performed between the service party and the query party, and the key data in the calculation process can be stored on the chain.

When a dispute occurs, the arbitrator can trace the source according to the evidence stored on the chain to ensure that the fraudulent behavior of the service provider is punished, thereby ensuring the stability of the entire system.

Fig. 2 is a schematic diagram of the general flow of a blockchain-based two-party privacy seeking system provided by an embodiment of the present invention. As shown in Fig. 2, a blockchain-based two-party privacy seeking system provided by an embodiment of the present invention ,include:

In the encryption phase, the service party encrypts its own data with a private key, and uploads the public key and encrypted data to the blockchain for easy sharing.

In the stage of signing the smart contract, the service party initiates the smart contract and signs the smart contract with the query party and the arbitrator.

In the intersection calculation stage, the intersection calculation is performed between the querying party and the server, and the intermediate calculation results are Hash calculated and uploaded to the blockchain for storage.

In the result verification stage, the inquiring party verifies the final calculation result, confirms whether the result is correct or applies to the arbitrator for arbitration.

In the arbitration verification stage, the arbitrator verifies according to the evidence stored on the chain, determines whether the inquiring party has fraudulent behavior, and makes a corresponding ruling.

In the confirmation stage, the inquiring party or the arbitrator invokes the signed smart contract to confirm the signature, thereby rewarding or punishing the service party.

It can be seen from the above embodiments that this application adopts blockchain and RSA encryption technical means, which provides a convenient platform for the service party and participants to conduct privacy disclosure, and at the same time solves the problem of the traditional third-party server privacy disclosure method. The third party may cooperate with the participants to do evil and be vulnerable to DDos attacks. The invention can solve the disadvantages of the traditional third-party server privacy seeking method, simplifies the management cost of contract signing, and increases the cost of the service party doing evil.

In the encryption phase, the service party encrypts its own data with a private key, and uploads the public key and encrypted data to the blockchain for easy sharing; this phase can include the following sub-steps:

Generate a key pair (E, D, N) using the RSA encryption algorithm. Specifically, this step may include the following sub-steps

To find N, first generate two random prime numbers p and q, these two prime numbers need to be relatively prime and not too small, then multiply p by q to get N, and record the least common multiple of p-1 and q-1 for L.

Find E, where E needs to meet two conditions, one is greater than 1 and smaller than L, and the other is that E and L are mutually prime.

Find D, where D must first be large enough, and must be greater than 1 and less than L, and the modulus of the product of E and D to L is 1.

Use the private key (D, N) to encrypt the plaintext to obtain the ciphertext C1.

Specifically, as shown in Figure 4, the server first uses the Hash function to perform hash calculations on the original data one by one, and then uses the private key (D, N) to encrypt each hash value to obtain the secret C = M ^D mod N , and then perform hash calculation on the ciphertext again to obtain C1.

Upload the public key (E, N) and ciphertext C1 to the blockchain for disclosure.

Specifically, the service party publishes the public key (E, N) to the blockchain for disclosure, and at the same time uploads the ciphertext C1 to the blockchain for storage, which is convenient for the querying party to download.

In the phase of signing the smart contract, the service party initiates the smart contract and signs the smart contract with the query party and the arbitrator; this phase can include the following sub-steps:

The service initiates a request to the blockchain and publishes a smart contract to the blockchain.

Specifically, the service party can set prices according to its own data value, and at the same time prove to the query party by designing an appropriate penalty mechanism, and publish it to the blockchain platform in the form of a smart contract.

The arbitrator receives the blockchain notification and signs it after confirming that the contract is legal.

Specifically, the arbitrator can review the smart contract issued by the service provider to ensure that the price is reasonable and the penalty mechanism meets the requirements. Sign the smart contract with the private key.

The inquiring party receives the block chain notification, and after verifying that the contract has been signed by the arbitrator, if it accepts the reward and punishment mechanism stipulated in the smart contract, it will sign on the smart contract.

Specifically, the inquiring party can download the public keys of the service party and the arbitrator from the blockchain platform, verify that the issuing body of the smart contract is correct and signed by the authoritative arbitrator, and if the pricing and penalty mechanism is received, the contract will be to sign.

In the intersecting calculation phase, the intersecting calculation is performed between the querying party and the server, and the intermediate calculation results are Hash calculated and uploaded to the blockchain for storage; this phase, as shown in Figure 3, can include the following sub-steps:

The query party randomly selects a random number for each element in its own data set, encrypts the random number with the public key (E, N) of the server, and then multiplies it with the hash value of the corresponding element to obtain the blinded data C _Enc , and then send the blinded data to the server.

Specifically, as shown in Figure 5, first perform Hash calculation on each data in its own collection, then generate a random number for each element, and encrypt it with the public key (E, N) of the server to obtain the encrypted Random number R _Enc = R ^E modN, then multiply the hash value of the element with R _Enc to get the blinded data C _Enc , and finally send the blinded data to the server, and upload the data to Blockchain platform for depositing certificates.

The service party receives the blinded data sent by the query party, decrypts it with its own private key (D, N) to obtain the decrypted data C _Dec , and sends the decrypted data to the query party.

Specifically, after receiving the blinded data from the querying party, the service party first verifies whether the hash value of the received data is the same as the hash value of the querying party's certificate stored on the chain, and if they are the same, it uses its own private key (D, N) to Decryption, that is, C _Dec = C _Enc ^D modN, and then send the decrypted data C _Dec to the querying party, perform Hash calculation on the data and upload it to the blockchain platform for deposit, otherwise refuse to execute the calculation.

The inquiring party receives the decrypted data sent by the service party and divides it by the random number selected during the blinding process to obtain the unblinded data C2.

Specifically, after receiving the decrypted data C _Dec = C1 ^D * Rmod N sent by the server, the inquiring party first verifies whether the hash value of these data is the same as the hash value stored by the server on the chain. If they are the same, they will receive Divide each data of the data by the corresponding random number R selected in the process of blinding, and then the data encrypted with the private key of the server can be obtained C2=C1 ^D mod N, if not the same, the calculation will not be performed.

The query party downloads the encrypted data of the service party from the blockchain platform, and calculates the encrypted data provided by the service party and the unblinded data to obtain the intersection of the two parties.

Specifically, the query party downloads the encrypted data of the service party from the blockchain platform, and then uses the same hash function as the service party to calculate the hash value C3=Hash(C2), and the encrypted data provided by the service party is unblinded. The intersection of both parties can be obtained by comparing C3.

In the result verification stage, the inquiring party verifies the final calculation result, confirms the signature or applies to the arbitrator for arbitration according to whether the result is correct or not; this stage may include the following sub-steps:

The query party can encrypt the data decrypted by the server party again using the public key of the server party to obtain the data before decryption by the server party. Hash calculation is performed on these data, and compared with the hash value of the query party’s blinded data that has been deposited on the blockchain platform before, it can be judged whether the service party has faithfully calculated according to the agreement.

Specifically, the query party can encrypt the data C _Dec decrypted by the server party again using the public key of the server party to obtain the blinded data of the query party, perform hash calculation on these data, and compare them with the data on the blockchain platform Comparing the hash value of the inquiring party that has already stored the certificate, it can be judged whether the server has performed the calculation truthfully.

If the service party does not have fraudulent behavior, it will sign on the smart contract, and give corresponding rewards to the service party according to the provisions of the contract.

Specifically, if the inquiring party finds that the received data hash value is the same as the inquiring party’s hash value stored on the chain after comparison, it will be determined that the inquiring party has faithfully performed calculations according to the agreement and can sign on the smart contract.

If the service provider is found to be fraudulent, it will apply to the arbitrator for arbitration and refuse to sign on the smart contract.

Specifically, if the inquiring party finds that the hash value of the received data is different from the inquiring party’s hash value stored on the chain after comparison, it will be determined that the inquiring party has not faithfully performed calculations according to the agreement, and can refuse to sign on the smart contract, and at the same time An application for arbitration may be made to the arbitrator.

In the arbitration verification verification phase, the arbitrator verifies based on the evidence stored on the chain, determines whether the inquiring party has fraudulent behavior, and makes a corresponding ruling; this phase may include the following sub-steps:

Compare the storage certificates on the blockchain during the calculation process of the service party and the query party on the blockchain.

Specifically, the arbitrator can download the hash certificates of the querying party and the server from the blockchain platform, and at the same time require the querying party and the server to provide intermediate calculation results. The correctness of the intermediate results can be compared by calculating the hash value. If the calculation result is correct, use the public key of the service party to re-encrypt the decrypted data sent by the service party to the query party, and compare it with the hash certificate of the query party on the chain to verify whether the service party has fraudulent behavior.

If the service party does have fraudulent behavior, it will sign and confirm on the smart contract, and the service party will be punished according to the pre-signed smart contract. The arbitrator can also choose to disclose the malicious behavior of the service party to the entire network.

Specifically, if the arbitrator finds that the service party has fraudulent behavior through on-chain traceability verification, it will sign at the penalty mechanism on the contract and punish the service party according to the pre-signed contract. Behavior is recorded on the chain to provide reference for other querying parties.

If there is no fraudulent behavior by the service party, the smart contract will be signed, and the service party will be rewarded accordingly according to the provisions of the smart contract.

Specifically, the arbitrator finds that the service party does not have fraudulent behavior through on-chain traceability verification, and then signs at the reward mechanism on the contract. At this time, even if there is no signature of the querying party on the contract, the pre-signed contract Reward the service party.

Effectiveness analysis of the two-party privacy seeking intersection system based on blockchain:

The server encrypts the local set with a private key, and the encrypted data is: S2=H'(S1 ^d modn), where S1=H(S).

The query side generates a corresponding random number for each element in the local collection and encrypts it with the public key of the server side. The encrypted data is: C _Enc =C1*R ^e mod n, where C1=H(C).

After the service party receives the encrypted data C2 from the query party, it decrypts it with its own private key, so

C _Dec = C _Enc ^d mod n

＝(C1*R ^e mod n) ^d mod n

＝(C1*(R ^e mod n)) ^d mod n

＝(C1 ^d *(R ^e mod n) ^d )mod n

＝(C1 ^d mod n)*((R ^e mod n) ^d ) mod n

＝(C1 ^d mod n)*((R ^e mod n) ^d )mod n

＝((C1 ^d mod n)*R)mod n#

After the query party receives the decrypted data C _Dec from the service party, since the random number in it is selected by itself, it only needs to remove the random number to unblind it.

C2=H'((C _Dec *(R ^Φ(n)-1 mod n))mod n)

=H'(((((C1 ^d mod n)*R)mod n)*(R ^Φ(n)-1 mod n))mod n)

=H'((((C1 ^d mod n)*R)*(R ^Φ(n)-1 ))mod n)

=H'(((C1 ^d mod n)*(R*(R ^Φ(n)-1 )))mod n)

=H'((C1 ^d mod n mod n)*(R*(R ^Φ(n)-1 )mod n)mod n)

＝H'(C1 ^d mod n)#

Therefore, in the end, the query party obtains the encrypted data S2=H'(S1 ^d mod N) of the service party, and the unblinded data C2=H'(C1 ^d mod n), since S1=H(S), C1= H(C), so S2=H'(S1 ^d mod N)=H'(H(S) ^d mod N), C2=H'(C1 ^d mod n)=H'(H(C) ^d mod n, Therefore, as long as the element S _i , i∈[0,n) of the server is equal to the element C _j , j∈[0,m) of the client, then S2 _i =C2 _j , i∈[0,n) and C _j , j ∈ [0, m). Therefore, it is only necessary to judge the relationship between S2 and C2, and then the intersection can be obtained correctly.

Corresponding to the aforementioned embodiment of a blockchain-based mutual privacy interrogation system, this application also provides an embodiment of a blockchain-based mutual privacy interrogation method, which includes:

The service party encrypts its own data with a private key, and uploads the public key and encrypted data to the blockchain for easy sharing.

The service party initiates a smart contract and signs a smart contract with the query party and the arbitrator.

Intersection calculations are performed between the querying party and the service party, and the intermediate calculation results are Hash calculated and uploaded to the blockchain for storage.

The inquiring party verifies the final calculation result, confirms whether the result is correct or applies to the arbitrator for arbitration.

The arbitrator verifies based on the evidence stored on the chain, determines whether the inquiring party has fraudulent behavior, and makes a corresponding ruling.

The inquiring party or the arbitrator invokes the signed smart contract for signature confirmation, thus rewarding or punishing the service party.

The electronic device of the present invention includes a central processing unit (CPU), which can execute various Appropriate action and handling. In RAM, various programs and data necessary for device operation can also be stored. The CPU, ROM, and RAM are connected to each other through a bus. Input/output (I/O) interfaces are also connected to the bus.

Multiple components in the device are connected to the I/O interface, including: input units, such as keyboards, mice, etc.; output units, such as various types of displays, speakers, etc.; storage units, such as magnetic disks, optical discs, etc.; and communication units, Such as network card, modem, wireless communication transceiver, etc. The communication unit allows the device to exchange information/data with other devices over a computer network such as the Internet and/or various telecommunication networks.

The processing unit executes various methods and processes described above, such as methods S101-S107, S201-S202. For example, in some embodiments, the methods S101-S107, S201-S202 can be implemented as computer software programs, which are tangibly contained in machine-readable media, such as storage units. In some embodiments, part or all of the computer program may be loaded and/or installed on the device via a ROM and/or a communication unit. When the computer program is loaded into the RAM and executed by the CPU, one or more steps of the methods S101-S107, S201-S202 described above may be performed. Alternatively, in other embodiments, the CPU may be configured to execute methods S101-S107, S201-S202 in any other appropriate manner (eg, by means of firmware).

The functions described herein above may be performed at least in part by one or more hardware logic components. For example, without limitation, exemplary types of hardware logic components that may be used include: field programmable gate array (FPGA), application specific integrated circuit (ASIC), application specific standard product (ASSP), system on a chip (SOC), load programmable logic device (CPLD), etc.

Program codes for implementing the methods of the present invention may be written in any combination of one or more programming languages. These program codes may be provided to a processor or controller of a general-purpose computer, a special purpose computer, or other programmable data processing devices, so that the program codes, when executed by the processor or controller, make the functions/functions specified in the flow diagrams and/or block diagrams Action is implemented. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media would include one or more wire-based electrical connections, portable computer discs, hard drives, random access memory (RAM), read only memory (ROM), erasable programmable read only memory (EPROM or flash memory), optical fiber, compact disk read only memory (CD-ROM), optical storage, magnetic storage, or any suitable combination of the foregoing.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person familiar with the technical field can easily think of various equivalents within the technical scope disclosed in the present invention. Modifications or replacements shall all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. A block chain-based two-party privacy intersection method is characterized by comprising the following steps:

the server encrypts the own data by using a private key, and uploads the public key and the encrypted data to the blockchain so as to be convenient for sharing;

the service side initiates an intelligent contract and signs an intelligent contract with the inquiring side and the arbitrating side;

performing intersection calculation between the inquiring party and the service party, carrying out hash calculation on the intermediate calculation result, and uploading the intermediate calculation result to a blockchain for certification;

the inquiring party verifies the final calculation result, and confirms or applies arbitration to the arbitrating party according to whether the result is correct or not;

the arbitrator verifies according to the certificate on the chain, judges whether the inquirer has fraudulent behaviors or not, and makes corresponding decisions;

the inquiring party or the arbitrating party invokes the signed intelligent contract to carry out signature confirmation, thereby giving rewards to the service party or punishing the service party.

2. The blockchain-based two-party privacy interaction method of claim 1, wherein the server encrypts its own data with a private key and uploads the public key and the encrypted data to the blockchain for sharing, comprising:

generating a key pair by adopting an encryption algorithm;

encrypting the plaintext by adopting a private key to obtain a ciphertext;

and uploading the public key and the ciphertext to the blockchain for disclosure.

3. The blockchain-based two-party privacy intersection method of claim 2, wherein the encryption algorithm is an RSA encryption algorithm.

4. The two-party privacy interaction method based on blockchain as in claim 1, wherein the server initiates an intelligent contract and makes an intelligent contract with the querying party and the arbitrating party, comprising:

the service initiates a request to the blockchain and issues an intelligent contract to the blockchain;

the secondary side receives the block chain notification, and signs after confirming that the contract is legal;

the inquiring party receives the block chain notification, verifies that the contract is signed by the arbitrator, and signs the contract if the rewarding and punishment mechanism specified by the intelligent contract is accepted.

5. The two-party privacy intersection method based on the blockchain as in claim 1, wherein the performing intersection calculation between the inquiring party and the serving party, and uploading the intermediate calculation result to the blockchain for certification after performing hash calculation, includes:

the inquiring party randomly selects a random number for each element in the data set, encrypts the random number by using a public key of the service party, multiplies the random number by a hash value of the corresponding element to obtain blinded data, sends the blinded data to the service party, hashes the blinded data and uploads the blinded data to the blockchain platform for verification;

the server receives the blind data sent by the inquiring party, decrypts the blind data by using the private key of the server to obtain decrypted data, then sends the decrypted data to the inquiring party, and uploads the decrypted data to the blockchain platform for verification after hash calculation;

the inquiring party receives the decryption data sent by the service party and divides the decryption data by the random number selected in the self-blinding process to obtain the blinding data;

the inquirer downloads the encrypted data of the server from the blockchain platform, and calculates the encrypted data provided by the server and the blinded data to obtain the intersection of the two parties.

6. The two-party privacy solving method based on blockchain as in claim 1, wherein the inquiring party verifies the final calculation result, confirms or applies arbitration to the arbitrating party according to whether the result is correct or not, and comprises the following steps:

the inquiring party can encrypt the data decrypted by the service party by using the public key of the service party again, so that the data before decryption by the service party can be obtained, hash calculation is carried out on the data, and the data is compared with the hash value of the blind data added by the inquiring party which is stored on the blockchain platform before, so that whether the service party carries out calculation according to a protocol can be judged;

if the service side does not have fraudulent conduct, signing is conducted on the intelligent contract, and corresponding rewards are given to the service side according to regulations on the contract;

if the service side is found to have fraudulent activity, the arbitrator is applied for arbitration, and signing on the intelligent contract is refused.

7. The blockchain-based two-party privacy interaction method of claim 1, wherein the arbitrator verifies based on the credentials on the chain, determines if the inquirer is fraudulent, and makes a corresponding decision, comprising:

comparing the certificates stored in the chain by the service party and the inquiring party in the calculating process:

if the service side does have fraudulent activity, signing and confirming on the intelligent contract, and punishing the service side according to the intelligent contract signed in advance, wherein the arbitrator can also select to disclose the malicious activity of the service side to the whole network;

if the service side does not have fraudulent conduct, signing on the intelligent contract, and carrying out corresponding rewarding on the service side according to the rule of the intelligent contract.

8. Two-party privacy intersection system based on block chain is characterized by comprising a server, a query party, a secondary party and a block chain module, wherein the two-party privacy intersection is performed by adopting the method of any one of claims 1-7.

9. An electronic device comprising a memory and a processor, the memory having stored thereon a computer program, characterized in that the processor, when executing the program, implements the method according to any of claims 1-7.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the method according to any one of claims 1-7.