Data right confirmation method and system based on block chain and homomorphic encryption

Abstract

The invention discloses a data right confirmation method and system based on a block chain and homomorphic encryption, and the method comprises the steps: a data provider generates a symmetric encryption key to encrypt target data, obtains a ciphertext of data to be subjected to right confirmation, calculates a hash value of the ciphertext, carries out the signature through a private key, and obtains a data credential of the data to be subjected to right confirmation; performing right confirmation application based on the data credential, and after the right confirmation application is passed, performing uplink storage on the data ciphertext by the data provider; when a data provider and a data user perform data transaction, a transaction condition is determined and a public key is applied, and a contract is signed and linked between the two parties; and after the contract is signed and chained, the signature and the account balance are verified, if the conditions are both met, the agreed amount is transferred from the data user to the data provider, and the data provider sends a decryption key to the data user. According to the method, the reliability and traceability of the data right confirmation information can be ensured, and the requirement of privacy protection during data transaction is met in combination with homomorphic operation.

Description

Technical Field

[0001] The present invention relates to the technical field of blockchain technology and data security, and in particular to a data rights confirmation method and system based on blockchain and homomorphic encryption. Background Art

[0002] Data, as an important resource, can be traded and used. However, with the advent of the big data era, the most difficult challenge in the data field lies in its easy access and copying characteristics, which leads to the blurring of the boundaries of data ownership. Therefore, the prerequisite for data sharing and circulation is to confirm the ownership of data. Data ownership confirmation mainly includes two aspects: on the one hand, it is to determine the right holder of the data, and on the other hand, it is to determine the content of the rights. Data ownership confirmation is the institutional foundation of data transactions and one of the core issues that must be solved for the development of the data industry. There are two main types of traditional data ownership confirmation: the first is to confirm the ownership by manual review, and the second is to automatically review the data through authoritative agencies. Based on this, there are several main problems in data rights confirmation: the diversity of the rights holders of data assets makes it difficult to define the rights holders in practice, and the multidimensionality of the data rights content makes it difficult to clarify the scope of rights owned when confirming the rights; secondly, when data is circulated, the implicit retention of data and its derivatives in multiple systems and multiple links will cause the problem of difficult traceability and control of data cross-system flow; in addition, when clarifying data ownership according to traditional methods or using blockchain to store data content and transactions, data and transaction amounts are in plain text, which can easily cause information leakage. Therefore, it is of great significance to design a data rights confirmation method based on blockchain with data confidentiality.

[0003] Based on the characteristics of data asset rights and the key points of data rights confirmation, a data rights confirmation method based on blockchain and homomorphic encryption is proposed. The decentralized, tamper-proof, open and transparent characteristics of blockchain are used to ensure the reliability and traceability of data rights confirmation information, and the Paillier homomorphic operation is combined to meet the privacy protection needs during data transactions. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a data rights confirmation method and system based on blockchain and homomorphic encryption to solve the problems of the background technology.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] In a first aspect, an embodiment of the present invention provides a data rights confirmation method based on blockchain and homomorphic encryption, including: a data provider generates a symmetric encryption key to encrypt target data to obtain a ciphertext of the data to be confirmed, calculates a hash value of the ciphertext, and signs it with a private key to obtain a data certificate of the data to be confirmed;

[0009] Apply for confirmation of ownership based on the data certificate. Once the confirmation of ownership is approved, the data provider will store the encrypted data on the chain;

[0010] When the data provider and the data user conduct data transactions, they will determine the transaction conditions and apply for the public key, and then sign the contract and upload it to the blockchain;

[0011] When the contract is signed and uploaded to the chain, the signature and account balance are verified. If all conditions are met, the agreed amount is transferred from the data user to the data provider, and the data provider sends the decryption key to the data user.

[0012] As a preferred solution of the data rights confirmation method based on blockchain and homomorphic encryption described in the present invention, before the data rights confirmation transaction is carried out, the data provider, the data user and the audit center each subject generates a corresponding public and private key pair locally, and submits a certificate signing application to the certificate authority, the application contains the public key and related information of each subject;

[0013] The certificate authority reviews the identity information of each subject. After the identity verification is passed, the certificate authority uses the private key to sign the certificate information of each subject and create a digital certificate for each subject.

[0014] After registration is completed, both the data provider and the data user have an initial point value; the audit center uses a homomorphic encryption algorithm to generate a public-private key pair and encrypt the initial points; at the same time, the blockchain ownership registration network is initialized.

[0015] As a preferred solution of the data rights confirmation method based on blockchain and homomorphic encryption described in the present invention, wherein: the data provider generates a symmetric encryption key to encrypt the target data, and the ciphertext of the data to be confirmed includes: the certificate issuing authority verifies the digital certificate of the data provider, and when the verification is passed, the data provider generates a symmetric encryption key to perform AES symmetric encryption on the data content to obtain the ciphertext of the data to be confirmed.

[0016] As a preferred solution of the data rights confirmation method based on blockchain and homomorphic encryption described in the present invention, wherein: the data provider generates a symmetric encryption key to encrypt the target data, and the ciphertext of the data to be confirmed includes: the certificate issuing authority verifies the digital certificate of the data provider, and when the verification is passed, the data provider generates a symmetric encryption key to perform AES symmetric encryption on the data content to obtain the ciphertext of the data to be confirmed.

[0017] As a preferred solution of the data confirmation method based on blockchain and homomorphic encryption described in the present invention, wherein: calculating the hash value of the ciphertext and signing it with a private key to obtain the data voucher of the data to be confirmed includes: calculating the hash value of the data ciphertext, and the data provider signs the hash value of the data to be confirmed using the ECDSA signature algorithm according to the private key of the digital certificate to obtain the hash value and signature of the data to be confirmed;

[0018] Apply for an authoritative timestamp from an authoritative trusted timestamp server based on the hash value of the data to be confirmed, generate a unique data certificate based on the confirmation data information, and send a confirmation application to the audit center, where the confirmation data information includes a hash value, a digital signature, and a timestamp.

[0019] As a preferred solution of the data rights confirmation method based on blockchain and homomorphic encryption described in the present invention, when the rights confirmation application is approved, the data provider stores the data ciphertext on the chain, including: the audit center verifies the received data certificate, and when the verification is passed, calculates the hash value of the data certificate and signs it to obtain the certificate signature;

[0020] The data certificate and certificate signature are uploaded to the blockchain, the obtained ownership record is uploaded to the blockchain ownership registration network, and the data provider is notified that the ownership confirmation is completed;

[0021] After receiving the confirmation of successful ownership, the data provider stores the encrypted data on the chain.

[0022] As a preferred solution of the data rights confirmation method based on blockchain and homomorphic encryption described in the present invention, the verification of signature and account balance includes:

[0023] When the signatures of both parties to the contract are legal and the account balances are sufficient, a homomorphic addition operation is performed on the account balance of the data provider, and a homomorphic subtraction operation is performed on the account balance of the data user. The transaction is recorded on the blockchain and both parties are notified of the transaction results.

[0024] After both parties confirm the transaction, the data provider sends the AES key to the data user. The data user downloads the encrypted data from the blockchain and decrypts it to obtain the target data.

[0025] In a second aspect, the present invention provides a data rights confirmation system based on blockchain and homomorphic encryption, comprising:

[0026] The authentication module is used by the data provider to generate a symmetric encryption key to encrypt the target data, obtain the ciphertext of the data to be authenticated, calculate the hash value of the ciphertext, and sign it with a private key to obtain the data certificate of the data to be authenticated;

[0027] The audit module is used to apply for confirmation of ownership based on the data certificate. When the confirmation application is approved, the data provider will store the encrypted data on the chain;

[0028] The transaction module is used to determine the transaction conditions and apply for the public key when the data provider and the data user conduct data transactions, and then sign the contract and upload it to the blockchain;

[0029] The data usage module is used to verify the signature and account balance after the contract is signed and uploaded to the chain. If all conditions are met, the agreed amount is transferred from the data user to the data provider, and the data provider sends the decryption key to the data user.

[0030] In a third aspect, the present invention provides a computing device, comprising:

[0031] Memory and processor;

[0032] The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the data rights confirmation method based on blockchain and homomorphic encryption are implemented.

[0033] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the data rights confirmation method based on blockchain and homomorphic encryption.

[0034] Compared with the prior art, the present invention has the following beneficial effects: when the present invention uses blockchain to confirm data rights, a unique identifier is generated using a hash function, and a corresponding relationship can be formed between data assets and data ownership certificates. The data ownership certificates are stored by blockchain, and have the characteristics of being unforgeable and tamper-proof, ensuring that the ownership of the data is clear. The data provider and the data user use the Paillier algorithm to encrypt the value of the data. When performing a transfer operation, the account balance and the transaction amount exist in the form of ciphertext, ensuring the privacy of the transaction. The user uses ECDSA signature to sign the data content and transaction contract, realizing the integrity of the data assets. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0036] Figure 1 A method flow chart of a data rights confirmation method and system based on blockchain and homomorphic encryption according to an embodiment of the present invention;

[0037] Figure 2 A data rights confirmation flow chart of a data rights confirmation method and system based on blockchain and homomorphic encryption according to an embodiment of the present invention;

[0038] Figure 3 A data transaction flow chart of a data rights confirmation method and system based on blockchain and homomorphic encryption according to an embodiment of the present invention;

[0039] Figure 4 This is an architecture diagram of a data rights confirmation system according to a method and system for data rights confirmation based on blockchain and homomorphic encryption as described in one embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0041] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0042] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0043] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0044] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] Example 1

[0047] Reference Figure 1 to Figure 4 , is an embodiment of the present invention, which provides a data rights confirmation method based on blockchain and homomorphic encryption, such as Figure 1 As shown, including:

[0048] S100: The data provider generates a symmetric encryption key to encrypt the target data, obtains the ciphertext of the data to be confirmed, calculates the hash value of the ciphertext, and signs it with a private key to obtain the data certificate of the data to be confirmed;

[0049] S200: Apply for confirmation of ownership based on the data certificate. When the confirmation of ownership is approved, the data provider stores the encrypted data on the chain;

[0050] S300: When the data provider and the data user conduct data transactions, they determine the transaction conditions and apply for the public key, and then sign the contract and upload it to the chain;

[0051] S400: After the contract is signed and uploaded to the blockchain, the signature and account balance are verified. If all conditions are met, the agreed amount is transferred from the data user to the data provider, and the data provider sends the decryption key to the data user.

[0052] It should be noted that data assets, as an important asset, involve data ownership issues in their circulation and application. Clarifying data ownership is the premise and basis for data transactions. Since data assets have the characteristic of unlimited replication, the first problem faced by data rights confirmation is that it is impossible to clarify the ownership of rights. If the rights are not clear, transfer and data circulation cannot be achieved. When using traditional methods such as manual review or automatic review by authoritative agencies to confirm data rights, it is difficult to clearly define data ownership between different subjects, and data ownership cannot be dynamically determined in complex data relationships; secondly, there are privacy protection issues in data rights confirmation. In the existing blockchain-based data rights confirmation technology, due to the characteristics of blockchain itself, openness, transparency and full-node verification, it is impossible to handle privacy data well; during the transaction process, the account balance and transaction amount exist in plain text, which cannot meet the needs of user privacy protection.

[0053] Therefore, this application uses blockchain to confirm data rights, and utilizes the characteristics of blockchain such as decentralization, immutability, openness, transparency, and traceability to record the confirmation information of data assets and the transaction and circulation of data assets, providing a clear chain of evidence for data ownership; data is uploaded to the chain in encrypted form to protect the security of data content; when trading data, homomorphic operations are used to achieve confidentiality of transaction amounts while performing operations without exposing the original data, effectively protecting the privacy of both parties to the transaction.

[0054] In the embodiment of the present application, before the data is traded for rights confirmation, the following steps are also included: the data provider, the data user, and the audit center generate corresponding public and private key pairs locally, and submit a certificate signing application to the certificate authority, which includes the public key and related information of each subject;

[0055] The certificate authority reviews the identity information of each subject. After the identity verification is passed, the certificate authority uses the private key to sign the certificate information of each subject and create a digital certificate for each subject.

[0056] After registration is completed, both the data provider and the data user have an initial point value; the audit center uses a homomorphic encryption algorithm to generate a public-private key pair and encrypt the initial points; at the same time, the blockchain ownership registration network is initialized.

[0057] In an optional embodiment, since the homomorphic encryption algorithm allows calculations to be performed directly on encrypted data without having to decrypt the data first, the homomorphic encryption methods that can be selected in this application include ElGamal encryption algorithm, RSA encryption algorithm, Benaloh homomorphic encryption, Paillier encryption algorithm, etc.

[0058] In a preferred embodiment, the application of the Paillier homomorphic encryption algorithm includes: setting and selecting two prime numbers p and q;

[0059] Compute \(n = pq\), select a random number \(g=n + 1\), compute \(\lambda(n)=(p - 1)(q - 1)\), select a random number \(\alpha\) such that \(1<\alpha<\lambda(n)\), compute \(L = g\ α \(\bmod n\ 2 , the public key is \(\{n,g\}\), and the private key is \(\{p,q,\lambda(n),\alpha\}\).

[0060] Input the plaintext \(m\), where \(0\leq m < n\); randomly select a number \(r\), where \(1\leq r < n\); compute the ciphertext \(c\): \(c = g\ m \cdot r\ n \(\bmod n\ 2 .

[0061] Input the ciphertext \(c\) and the private key \(\{p,q,\lambda(n),\alpha\}\), compute the decryption result: \(m = L\ λ(n) \cdot c\ n \(\bmod n\ 2 .

[0062] Given two ciphertexts \(c1\) and \(c2\), with the corresponding plaintexts \(m1\) and \(m2\), perform the addition calculation \(c3 = c1\cdot c2\bmod n\ 2 , and the corresponding plaintext is \(m3 = m1 + m2\bmod n\).

[0063] Given a ciphertext \(c\), with the corresponding plaintext \(m\), and a scalar \(k\), perform the multiplication calculation \(c' = c\ k \(\bmod n\ 2 , and the corresponding plaintext is \(m = k\cdot m\bmod n\).

[0064] Exemplarily, when a user performs the user registration process before a data rights confirmation transaction, it includes steps A1 - A4:

[0065] A1: The data provider A / data user B / audit center T first generate their respective public - private key pairs locally: the public key \(pk\) of the data provider A and the private key \(sk\ A , the public key \(pk\) of the data user B and the private key \(sk\ B , the public key \(pk\) of the audit center T and the private key \(sk\ T .

[0066] A2: Submit a certificate signature application to the certificate authority CA, which includes their respective public keys and related information. CA verifies the identity information of each entity.

[0067] A3: After the identity verification is passed, CA uses its own private key to sign the certificate information of each entity and create digital certificates \(Cert\ A , \(Cert\ B , \(Cert\T .

[0068] A4: After registration is completed, both the data provider and the data user have an initial score. The audit center uses the Paillier encryption algorithm to generate a public-private key pair pk P ,sk P , encrypt the initial score; at the same time initialize a blockchain ownership registration network W.

[0069] In the embodiments of this application, refer to Figure 2 and Figure 4 The data provider generates a symmetric encryption key to encrypt the target data, and the ciphertext of the data to be confirmed includes: the certificate authority verifies the digital certificate of the data provider. When the verification is passed, the data provider generates a symmetric encryption key to perform AES symmetric encryption on the data content to obtain the ciphertext of the data to be confirmed.

[0070] In the embodiment of the present application, the hash value of the ciphertext is calculated and signed with a private key to obtain the data voucher of the data to be confirmed, including: calculating the hash value of the data ciphertext, the data provider signs the hash value of the data to be confirmed using the ECDSA signature algorithm according to the private key of the digital certificate, and obtaining the hash value and signature of the data to be confirmed;

[0071] Apply for an authoritative timestamp from an authoritative trusted timestamp server based on the hash value of the data to be confirmed, generate a unique data certificate based on the confirmation data information, and send a confirmation application to the audit center, where the confirmation data information includes a hash value, a digital signature, and a timestamp.

[0072] It should be noted that the purpose of generating a unique data credential in the embodiment of the present application is to ensure that the identity and source of the data can be traced.

[0073] In an optional implementation, the ECDSA signature algorithm includes:

[0074] Key generation: Select an elliptic curve and base point G, select a private key d, and calculate the corresponding public key Q, Q = dG. This calculation is a point addition operation.

[0075] Message digest: Hash the message M to be signed to obtain the message digest h=H(M), where H is the hash function.

[0076] Signature: Select a random number k, calculate kG, get the point (x1, y1), calculate r and s, where r = x1 mod n, s = k -1 (h+dr)mod n, where n is the order of the elliptic curve, we get the signature: (r,s).

[0077] Verify the signature: Use the public key Q and signature (r, s) to calculate w = s-1 mod n, calculate u1=hw mod n and u1=rwmod n, calculate the point (x′1,y′1)=u1G+u2Q, and verify whether x′1 mod n is equal to r. If so, the signature is valid.

[0078] In the embodiment of the present application, when the right confirmation application is approved, the data provider stores the data ciphertext on the chain, including: the audit center verifies the received data certificate, and when the verification is passed, calculates the hash value of the data certificate and signs it to obtain the certificate signature;

[0079] The data certificate and certificate signature are uploaded to the chain, the obtained ownership record is uploaded to the blockchain ownership registration network, and the data provider is notified that the ownership is completed;

[0080] After the data provider receives the confirmation of successful ownership, the encrypted data will be stored on the chain.

[0081] It should be noted that if the authentication application sent to the audit center fails to pass the verification, the data provider will re-use AES to symmetrically encrypt and sign the data content until the data certificate passes the authentication application.

[0082] Exemplarily, the data provider's application for rights confirmation includes steps B1 to B6:

[0083] B1: The certificate authority CA verifies the digital certificate Cert of the data provider A After verification, the data provider generates a symmetric encryption key k AES For data content M = {m i},(i∈[1,n]) performs AES symmetric encryption Enc(k AES , M), and obtain the ciphertext C of the data to be authenticated = {c i},(i∈[1,n]).

[0084] B2: Calculate the hash value h of the data ciphertext C =H(C), H is the hash function, h C It is the unique identifier of the data; the data provider uses the private key sk of the digital certificate A The hash value h of the data to be confirmed C Use ECDSA signature algorithm to sign Sign(sk A ,h C )=Sign A , get the hash value h of the data to be confirmed C and Sign A .

[0085] B3: Generate digital certificate Y. Apply for an authoritative timestamp from the authoritative TSA based on the hash value of the data to be confirmed. Then, based on the data information, including hash value, digital signature, and timestamp, generate a unique data certificate Y and send the confirmation application to the audit center T.

[0086] B4: Audit center T verifies the received data certificate Y. A ,pk A ), after verification, calculate the hash value h of the data credential T =H(Y), and sign Sign(sk T ,h T )=Sign T , get the certificate signature Sign T .

[0087] B5: Data certificate Y and certificate signature Sign T The ownership record is uploaded to the blockchain ownership registration network W, and the data provider is notified that the ownership is complete.

[0088] B6: After receiving the confirmation, the data provider stores the data ciphertext C on the chain.

[0089] It should be noted that the data ownership information is stored on the blockchain in the form of verifiable data certificates, which not only realizes the function of data ownership confirmation, but also ensures that the data ownership information can be verified and prevented from tampering. Combined with the timestamp generated by the authoritative TSA, it improves the credibility and authority of data ownership confirmation and realizes the declaration and protection of data ownership.

[0090] In the embodiments of this application, refer to Figure 3 , determine the transaction conditions and apply for the public key, and sign the contract between the two parties and upload it to the chain, including: the transaction conditions determined by the data provider and the data user include the data content and transaction value of the transaction;

[0091] When the transaction conditions are determined, both parties apply to the audit center for an encryption public key. The data provider uses AES to encrypt the transaction data content and executes the data rights confirmation application. The data provider uses the encryption public key to encrypt the data value.

[0092] The hash value of the data content is calculated and used together with the encrypted data value to form a transaction contract. The data provider and the data user use their respective private keys and the ECDSA signature algorithm to sign the contract, package the signed contract on the chain, and create a transaction request.

[0093] In the embodiment of the present application, verifying the signature and account balance includes:

[0094] When the signatures of both parties to the contract are legal and the account balances are sufficient, a homomorphic addition operation is performed on the account balance of the data provider, and a homomorphic subtraction operation is performed on the account balance of the data user. The transaction is recorded on the blockchain and both parties are notified of the transaction results.

[0095] After both parties confirm the transaction, the data provider sends the AES key to the data user. The data user downloads the encrypted data from the blockchain and decrypts it to obtain the target data.

[0096] It should be noted that when any of the conditions of the signature legitimacy and account balance of both parties to the contract are not met, the transaction fails and the data user and data provider need to renegotiate the transaction.

[0097] Exemplarily, the data transaction between two users includes steps C1 to C3:

[0098] C1: The data user and the data provider negotiate the data content and value score of the transaction. After the negotiation is completed, the two parties apply to the audit center for the Paillier encrypted public key pk p The data provider uses AES to encrypt the transaction data content Enc(k AES ,data)=C data , and execute the data confirmation application; the data provider uses the public key pk encrypted by Paillier p Encrypt the value score of the data Enc(score, pk p )=C s ; Then calculate the hash value h of data data =H(data),h data and C s Together constitute the transaction contract file = (h data ,C s ).

[0099] C2: The data user and the data provider sign a contract, and the data provider uses its own private key sk to access the contract file. A Sign using the ECDSA signature algorithm: Sign(sk A ,file)=Sign A ; Similarly, the data user uses his own private key sk for the contract file B Sign using the ECDSA signature algorithm: Sign(sk B ,file)=Sign B . The signed contract (file,Sign A ,Sign B ,pk A ,pkB )Package on the chain and create a transaction request.

[0100] C3: Trigger the smart contract and first verify the legitimacy of the signatures of both parties signing the contract: Verify (Sign A ,pk A )→{0,1},Verify(Sign B ,pk B )→{0,1}, and whether the account balance is sufficient, to prove the identity of both parties and ensure the non-repudiation of the transaction. After verification, the transfer operation is performed. The transfer operation uses Paillier homomorphic operation. Perform a homomorphic addition operation on the account balance of the data provider: account balance Bal′ A =Bal A +C s The account balance of the data user is Bal′ B =Bal B -C s The transaction is recorded on the blockchain and both parties are notified of the transaction results. After both parties confirm the transaction, the data provider will send the AES key k AES Sent to the user. The user downloads C from the blockchain data , decrypt Dec(C data ,k AES )=data.

[0101] Example 2

[0102] In an exemplary embodiment, a data rights confirmation system based on blockchain and homomorphic encryption is also provided in this embodiment, including:

[0103] The rights confirmation module is used by the data provider to generate a symmetric encryption key to encrypt the target data, obtain the ciphertext of the data to be confirmed, calculate the hash value of the ciphertext, and sign it with a private key to obtain the data certificate of the data to be confirmed;

[0104] The audit module is used to apply for rights confirmation based on data credentials. When the rights confirmation application is approved, the data provider will store the data ciphertext on the chain;

[0105] The transaction module is used when the data provider and the data user conduct data transactions. By determining the transaction conditions and applying for the public key, the two parties sign the contract and upload it to the chain;

[0106] The data usage module is used to verify the signature and account balance after the contract is signed and uploaded to the chain. If all conditions are met, the agreed amount will be transferred from the data user to the data provider, and the data provider will send the decryption key to the data user.

[0107] Furthermore, the data rights confirmation system based on blockchain and homomorphic encryption also includes:

[0108] The user registration module is used by data providers, data users and audit center entities to generate corresponding public and private key pairs locally and submit certificate signing applications to the certificate authority. The application contains the public keys and related information of each entity.

[0109] The certificate issuance module is used by the certificate authority to review the identity information of each subject. After the identity authentication is passed, the certificate authority uses the private key to sign the certificate information of each subject and create a digital certificate for each subject.

[0110] The initialization module is used to ensure that both the data provider and the data user have initial points after registration is completed. The audit center uses a homomorphic encryption algorithm to generate a public-private key pair and encrypt the initial points. At the same time, the blockchain ownership registration network is initialized.

[0111] In an optional embodiment, a data rights confirmation system based on blockchain and homomorphic encryption may perform the following steps:

[0112] The certificate authority verifies the digital certificate of the data provider. Once the verification is passed, the data provider generates a symmetric encryption key to perform AES symmetric encryption on the data content to obtain the ciphertext of the data to be authenticated.

[0113] Calculate the hash value of the data ciphertext. The data provider uses the ECDSA signature algorithm to sign the hash value of the data to be confirmed based on the private key of the digital certificate to obtain the hash value and signature of the data to be confirmed.

[0114] Apply for an authoritative timestamp from an authoritative trusted timestamp server based on the hash value of the data to be confirmed, generate a unique data certificate based on the confirmation data information, and send a confirmation application to the audit center, where the confirmation data information includes a hash value, a digital signature, and a timestamp.

[0115] The audit center verifies the received data certificate. Once the verification is passed, the hash value of the data certificate is calculated and signed to obtain the certificate signature.

[0116] The data certificate and certificate signature are uploaded to the chain, the obtained ownership record is uploaded to the blockchain ownership registration network, and the data provider is notified that the ownership is completed;

[0117] After the data provider receives the confirmation of successful ownership, the encrypted data will be stored on the chain.

[0118] The transaction conditions determined by the data provider and the data user include the data content and transaction value of the transaction;

[0119] When the transaction conditions are determined, both parties apply to the audit center for an encryption public key. The data provider uses AES to encrypt the transaction data content and executes the data rights confirmation application. The data provider uses the encryption public key to encrypt the data value.

[0120] The hash value of the data content is calculated and used together with the encrypted data value to form a transaction contract. The data provider and the data user use their respective private keys and the ECDSA signature algorithm to sign the contract, package the signed contract on the chain, and create a transaction request.

[0121] In an optional embodiment, data provider A is a common node in the blockchain network, responsible for providing original data, and is willing to provide data resources to data users to obtain points. The data content is signed with a private key and uploaded to the blockchain to clarify data ownership, and the data content is encrypted to protect data privacy.

[0122] Data user B is an ordinary node in the blockchain network, a user who has demand for data resources and is willing to pay points in exchange for data resources.

[0123] Audit Center T is an audit node in the blockchain network, which is used to audit the confirmation application: including verifying whether the data and its signature are complete, and putting the confirmation record on the chain. The public key of the Paillier algorithm that stores the encrypted account balance is provided to both parties when conducting data transactions.

[0124] The certificate authority CA is a CA node in the blockchain network, responsible for reviewing the identity and qualifications of applicants, generating and issuing digital certificates for legitimate users. The issued digital certificate has legal effect. The digital certificate contains a public key that can be used to verify the electronic signature of the applicant. After verification, the electronic signature is protected by law, and the signatory cannot deny the content of the signature.

[0125] Blockchain is used to store information such as data resource ownership records, encrypted data resources, and data transaction records to ensure the security and traceability of data resources and corresponding records; deploy smart contracts, and use smart contracts in data transactions to ensure that both parties to the transaction abide by the agreements and rules, verify the identities and legitimacy of both parties to the transaction, and realize the function of transfer.

[0126] The authoritative trusted timestamp server TSA issues legally binding authoritative timestamps based on applicants. The ECDSA signature algorithm is used by participants to sign data. The Paillier homomorphic encryption algorithm is used to encrypt the value of data during data transactions, and to protect the privacy of data using homomorphic operations during data transfers.

[0127] The present invention uses blockchain to confirm data ownership, and utilizes the characteristics of blockchain such as decentralization, immutability, openness, transparency, and traceability to record the confirmation information of data assets and the transaction and circulation of data assets, providing a clear chain of evidence for data ownership; data is uploaded to the chain in ciphertext form to protect the security of data content; when trading data, Paillier homomorphic operations are used to achieve confidentiality of the transaction amount while performing operations without exposing the original data, effectively protecting the privacy of both parties to the transaction.

[0128] This embodiment further provides a computing device, which is applicable to the case of a data rights confirmation method based on blockchain and homomorphic encryption, including:

[0129] Memory and processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the data rights confirmation method based on blockchain and homomorphic encryption as proposed in the above embodiment.

[0130] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method for data rights confirmation based on blockchain and homomorphic encryption proposed in the above embodiment is implemented.

[0131] The storage medium proposed in this embodiment and the method for implementing data rights confirmation based on blockchain and homomorphic encryption proposed in the above embodiment belong to the same inventive concept. For technical details not fully described in this embodiment, please refer to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0132] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0133] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A data rights confirmation method based on blockchain and homomorphic encryption, characterized in that: include: The data provider generates a symmetric encryption key to encrypt the target data, obtains the ciphertext of the data to be authenticated, calculates the hash value of the ciphertext, and signs it with a private key to obtain the data certificate of the data to be authenticated; Apply for confirmation of ownership based on the data certificate. Once the confirmation of ownership is approved, the data provider will store the encrypted data on the chain; When the data provider and the data user conduct data transactions, they will determine the transaction conditions and apply for the public key, and then sign the contract and upload it to the blockchain; When the contract is signed and uploaded to the chain, the signature and account balance are verified. If all conditions are met, the agreed amount is transferred from the data user to the data provider, and the data provider sends the decryption key to the data user.

2. The data rights confirmation method based on blockchain and homomorphic encryption as claimed in claim 1 is characterized in that: Before the data is traded for rights confirmation, the following procedures are also required: the data provider, data user, and audit center entities generate corresponding public and private key pairs locally, and submit a certificate signing application to the certificate authority. The application contains the public key and related information of each entity; The certificate authority reviews the identity information of each subject. After the identity verification is passed, the certificate authority uses the private key to sign the certificate information of each subject and create a digital certificate for each subject. After registration is completed, both the data provider and the data user have an initial point value; the audit center uses a homomorphic encryption algorithm to generate a public-private key pair and encrypt the initial points; at the same time, the blockchain ownership registration network is initialized.

3. The data rights confirmation method based on blockchain and homomorphic encryption as claimed in claim 2 is characterized in that: The data provider generates a symmetric encryption key to encrypt the target data, and the ciphertext of the data to be confirmed includes: the certificate authority verifies the digital certificate of the data provider. When the verification is passed, the data provider generates a symmetric encryption key to perform AES symmetric encryption on the data content to obtain the ciphertext of the data to be confirmed.

4. The data rights confirmation method based on blockchain and homomorphic encryption as claimed in claim 3 is characterized in that: Calculate the hash value of the ciphertext and sign it with the private key to obtain the data certificate of the data to be confirmed, including: Calculate the hash value of the data ciphertext, and the data provider signs the hash value of the data to be confirmed using the ECDSA signature algorithm according to the private key of the digital certificate to obtain the hash value and signature of the data to be confirmed; Apply for an authoritative timestamp from an authoritative trusted timestamp server based on the hash value of the data to be confirmed, generate a unique data certificate based on the confirmation data information, and send a confirmation application to the audit center, where the confirmation data information includes a hash value, a digital signature, and a timestamp.

5. The data rights confirmation method based on blockchain and homomorphic encryption as claimed in claim 4 is characterized in that: When the confirmation application is approved, the data provider stores the encrypted data on the chain, including: the audit center verifies the received data certificate, and when the verification is passed, calculates the hash value of the data certificate and signs it to obtain the certificate signature; The data certificate and certificate signature are uploaded to the blockchain, the obtained ownership record is uploaded to the blockchain ownership registration network, and the data provider is notified that the ownership is completed; After receiving the confirmation of successful ownership, the data provider stores the encrypted data on the chain.

6. The data rights confirmation method based on blockchain and homomorphic encryption as claimed in claim 5 is characterized in that: Determine the transaction conditions and apply for the public key, and sign the contract between the two parties and upload it to the blockchain, including: the transaction conditions determined by the data provider and the data user include the data content and transaction value of the transaction; When the transaction conditions are determined, both parties apply to the audit center for an encryption public key. The data provider uses AES to encrypt the transaction data content and executes the data rights confirmation application. The data provider uses the encryption public key to encrypt the data value. The hash value of the data content is calculated and together with the encrypted data value, it constitutes a transaction contract. The data provider and the data user use their respective private keys and the ECDSA signature algorithm to sign the contract, package the signed contract on the chain, and create a transaction request.

7. The data rights confirmation method based on blockchain and homomorphic encryption as claimed in claim 6 is characterized in that: Verifying signatures and account balances includes: When the signatures of both parties to the contract are legal and the account balances are sufficient, a homomorphic addition operation is performed on the account balance of the data provider, and a homomorphic subtraction operation is performed on the account balance of the data user. The transaction is recorded on the blockchain and both parties are notified of the transaction results. After both parties confirm the transaction, the data provider sends the AES key to the data user. The data user downloads the encrypted data from the blockchain and decrypts it to obtain the target data.

8. A data rights confirmation system based on blockchain and homomorphic encryption, characterized in that: include: The authentication module is used by the data provider to generate a symmetric encryption key to encrypt the target data, obtain the ciphertext of the data to be authenticated, calculate the hash value of the ciphertext, and sign it with a private key to obtain the data certificate of the data to be authenticated; The audit module is used to apply for confirmation of ownership based on the data certificate. When the confirmation application is approved, the data provider will store the encrypted data on the chain; The transaction module is used to determine the transaction conditions and apply for the public key when the data provider and the data user conduct data transactions, and then sign the contract and upload it to the blockchain; The data usage module is used to verify the signature and account balance after the contract is signed and uploaded to the chain. If all conditions are met, the agreed amount is transferred from the data user to the data provider, and the data provider sends the decryption key to the data user.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, the steps of the data rights confirmation method based on blockchain and homomorphic encryption are implemented as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the data rights confirmation method based on blockchain and homomorphic encryption as described in any one of claims 1 to 7.

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