CN-122022798-A - Blockchain auditable privacy transaction method suitable for cross-border trade settlement

CN122022798ACN 122022798 ACN122022798 ACN 122022798ACN-122022798-A

Abstract

The invention relates to the technical field of information security passwords and blockchains, in particular to a blockchain auditable privacy transaction method suitable for cross-border trade settlement, which is based on double hidden promises and zero knowledge proof protocols, and constructing a privacy transaction model, and respectively generating public and private key pairs meeting specific mathematical relations for each participating enterprise by a supervision organization to form verifiable privacy transaction. The sender enterprise constructs an asset credential, a disposable address and an audit ciphertext which hide the identity and the amount of the two parties of the transaction, and generates a zero knowledge proof set. The consensus node achieves transaction consensus by verifying the validity of the zero knowledge proof set. The recipient enterprise identifies the transaction as self by scanning the blockchain and computing a matching disposable address. After the supervision organization obtains the authorization, the identity tracing, the amount decryption and the statistical audit of both sides of the transaction can be executed for the on-chain transaction. The invention realizes the strong privacy protection of transaction data through the cryptology promise and the zero knowledge proof mechanism, avoids the leakage of sensitive business information, ensures the transaction privacy through the supervision audit system, simultaneously endows legal audit capability to the supervision institution, and improves the practicability and the safety of the system under strong compliance scenes such as cross-border trade and the like.

Inventors

ZHAO MENG
WANG HUIPING
WANG YUJUE
ZHENG HAIBIN
GUO ZHENWEI
WU QIANHONG

Assignees

北京航空航天大学杭州创新研究院
北京航空航天大学

Dates

Publication Date: 20260512
Application Date: 20251201

Claims (7)

1. A blockchain auditable private transaction method suitable for cross-border trade settlement, comprising the steps of: step 1, a supervision organization selects a security parameter and an anti-collision hash function, generates a system public parameter, a self master key pair and an audit trapdoor, and writes the public parameter into a block chain initial block; Step 2, each participating enterprise registers with the supervision organization, and the supervision organization generates public and private key pairs meeting specific mathematical relations for the participating enterprises; Step 3, the sender enterprise builds an asset credential hiding the identity and the amount of the transaction party based on the receiver enterprise public key, the transfer amount and the system participation enterprise public key set, generates a disposable transaction address and an audit ciphertext, and generates a plurality of zero knowledge proofs for proving the transaction rationality; Step 4, the consensus node performs validity verification on each zero knowledge proof in the private transaction, ensures that the transaction is not generated or destroyed by blank, is not invalid, can identify the consistency of a sender and a receiver and the like, and packages and links the valid transaction; Step 5, the receiver enterprise scans the transaction on the blockchain, and identifies and confirms the transaction belonging to the person by calculating the shared secret and the one-time address matching mechanism; and 6, after the supervision organization obtains the authorization, performing statistical audit operations such as identity tracing, amount decryption and the like on the transactions on the chain, and realizing compliance supervision on transaction behaviors.
2. The blockchain auditable private transaction method suitable for cross-border trade settlement of claim 1, The execution process of the step 1 comprises the following steps: Step 1.1, selecting safety parameters by the monitoring mechanism Au The system is according to Is selected from big prime numbers Respectively calculate And ; Step 1.2 monitoring mechanism Au according to multiplication group Constructing a cyclic subgroup with larger order And randomly select the generator of the group ; Step 1.3. The supervision organization Au selects a collision-resistant hash function All characteristics of the collision-resistant hash function are satisfied, the input is character string with any length, and the output is Is an element of (2); step 1.4, the supervision mechanism Au runs a random number generation algorithm and selects a random number As its private key, and calculate As its public key; step 1.5 monitoring agency Au construction System trapdoor ; Finally, the system common parameters are expressed as The supervision organization Au and consensus node CN will And Stored as audit trapdoor secrets.
3. The blockchain auditable private transaction method suitable for cross-border trade settlement of claim 2, The execution process of the step 2 comprises the following steps: Step 2.1 enterprises Submitting registration information to a regulatory agency; step 2.2. The supervision agency Au generates public and private key pairs for the enterprise Satisfies the following conditions 。
4. The blockchain auditable private transaction method suitable for cross-border trade settlement of claim 3, The execution process of the step 3 comprises the following steps: Step 3.1 sender Enterprise For each recipient enterprise Computing asset credentials Wherein In order to be a blinding factor, Representing a transaction In (a) Is a transaction amount of (a). Wherein for sender enterprises Asset change And blinding factor For the receiver enterprise Asset change And randomly selecting a blinding factor For other participating enterprises Asset change 0 Simultaneous random selection of blinding factors . The blinding factors satisfy ; Step 3.2 sender Enterprise Randomly select Calculate the disposable address At the same time disclose promise value ; Step 3.3 sender Enterprise Randomly select Calculation of And generate Ciphertext of (2) Wherein ; Step 3.4 sender Enterprise To ensure the rationality of the transaction, four certificates are also required; Specifically, this step 3.4 comprises the following sub-steps: Step 3.4.1 proof that the transaction does not create a credential or destroy the asset, which proof is recorded as . First calculate the product of all asset credentials Because of And is also provided with Therefore, it is Mod N, calculation at verification When the product is 1, the fact that the transaction does not generate a credential or destroy the asset can be proved; Step 3.4.2 prove that the invalid uplink with transaction amount of 0 is prevented, which proves to be recorded . If the amount of all enterprises in a transaction Then for any business Its asset credentials . As the supervision authorities Au know It can be calculated and stored So the authorities can compare in turn And (3) with Whether equal. If equal, then an invalid transaction; Step 3.4.3 prove that the consensus node CN can be correctly identified I.e. the transaction cannot be counterfeited to other businesses' transfers to themselves, which prove to be recorded as . First, the consensus node CN sequentially corresponds to each enterprise Calculation of . As the consensus node CN knows One by one during verification When a certain is When determining Is the transaction initiator and The corresponding asset credential is negative; Step 3.4.4 proof that the same recipient public Key was used in generating the one-time Address and ElGamal encryption It proves to be . First selecting a random number Calculation of Then calculate challenge values respectively And response value Finally, output the evidence . Respectively calculating during verification Challenge value . If it is The same public key of the receiver is used in the generation of the disposable address and the ElGamal encryption ; Finally, output transaction And writes it to the blockchain.
5. The blockchain auditable private transaction method suitable for cross-border trade settlement of claim 4, The execution process of the step 4 comprises the following steps: Step 4.1 consensus node CN calculation Verification of Whether mod N holds. If so, proving that the transaction does not generate a credential or destroy the asset; step 4.2. Consensus node CN calculates transaction initiator Asset credentials of (a) And (3) with Whether equal. If equal, then the transaction is invalid; Step 4.3. Consensus node CN calculates a certain value Whether or not it is. If true then determine Is the transaction initiator and The corresponding asset credential is negative; step 4.4. The consensus node CN calculates the challenge value Whether or not it is. If true, then prove that the same public key of the receiver is used in generating the disposable address and the ElGamal encryption 。
6. The blockchain auditable private transaction method suitable for cross-border trade settlement of claim 5, The execution process of the step 5 comprises the following steps: step 5.1 receiver Enterprise First scan transaction Tx on blockchain, calculate shared secret Whether or not equal to the published commitment D; Step 5.2 receiver Enterprise Calculation of . If it is If true, the transaction belongs to the receiver enterprise 。
7. The blockchain auditable private transaction method suitable for cross-border trade settlement of claim 6, The execution process of the step 6 comprises the following steps: Step 6.1, supervision mechanism Au is applied to sender enterprises And (5) carrying out identity tracing. Find the satisfaction of Is of the enterprise of (a) Then according to Searching corresponding sender enterprises Identity of (c); Step 6.2. Supervision agency Au is applied to the enterprise of the receiver And (5) carrying out identity tracing. The regulatory agency first calculates . Then decrypt Obtaining . Calculation of If (if) According to Searching corresponding receiver enterprise Identity of (c); Step 6.3 supervision authorities Au to specify asset credentials Using audit trapdoors And known sender enterprises Private key of (a) Calculation of Thereby decrypting the transaction amount ; Step 6.4. Regulatory agency Au requires enterprises Provided for in a time period Asset credential aggregate value within And blinding factor aggregate value Sum of purported asset changes . The regulatory agency Au then calculates the theoretical aggregate value And verify Whether or not it is. If true, then the enterprise During a time period Total amount of internal asset change Accurate.

Description

Blockchain auditable privacy transaction method suitable for cross-border trade settlement Technical Field The invention relates to the technical field of information security passwords and blockchains, in particular to a blockchain auditable privacy transaction method suitable for cross-border trade settlement. Background The privacy transaction scheme based on the blockchain allows a plurality of participants to execute an asset transfer protocol on a public distributed ledger, and simultaneously conceals sensitive information of transactions by a cryptography method, so that value concealing circulation is finally realized. The related art may further be used to protect the identity and amount privacy of parties to the transaction, thereby enabling business-sensitive blockchain applications. Based on this, it can be seen that privacy transactions are the basis for blockchain applications in high value business scenarios. Since the related art of privacy cryptocurrencies (e.g., monero and Zcash) has been proposed, a number of privacy protection schemes have been proposed so far, some relying on a hybrid pool, while others employ zero knowledge proof. However, the current mainstream research scheme is to ensure the privacy of transactions, and generally deprives the auditing capability of the regulatory authorities, so that the current mainstream research scheme is not suitable for business application scenarios constrained by strict laws and compliance requirements. Assuming that a plurality of enterprises in a cross-border trade alliance chain are distributed in different countries, a payment mechanism based on a blockchain is required to be established for realizing efficient settlement, and supervision authorities such as customs, tax and the like are required to be capable of actively tracing the identities of both parties of suspicious transactions and performing decryption audit on specific transaction amounts after obtaining authorization. To address this problem, trade companies need to employ a blockchain privacy trading scheme to hide their business information. Clearly, the regulatory authorities are required here to be able to actively initiate audit algorithms for identity revealing and amount decrypting, if necessary, without having to participate in the construction of each transaction, etc. Thus, the trade company should be able to actively perform the private transaction process while the regulatory authorities remain authoritative for the legal initiative to intervene and perform the audit. For the problems, a better solution idea is to construct a blockchain privacy transaction mechanism supporting supervision intervention, write the cryptographic promise and audit trails generated by the transaction into the blockchain, and verify the validity of the transaction by all nodes by means of the attribute that the blockchain has data which is not tamperable, publicly verifiable and the like. Currently, some researchers have proposed privacy protection schemes supporting supervision, but most of them do not support the collaborative audit requirement of the supervision authorities for flexibly tracing transaction identities and precisely decrypting transaction amounts in the above-mentioned scenarios, or sacrifice excessive efficiency and privacy in realizing the above-mentioned functions. The auditable privacy transaction method based on the blockchain provided by the invention classifies all entities into four types according to the difference of functions of participants in transaction and supervision flows, namely transaction sender enterprises, transaction receiver enterprises, supervision institutions and consensus nodes. The transaction sender business is the initiator of the private transaction agreement and may select the transaction receiver business and set the transfer amount. The business of the transaction receiver needs to scan and identify the online transaction and analyze the transaction content by using the private key of the business receiver. The supervision organization does not need to participate in the construction and broadcasting of the transaction in the whole transaction process, but can actively trace the identities of both parties of the uplink transaction, decrypt the encrypted transaction amount and verify the statistical transaction amount of a specific entity in a time period after the supervision organization obtains the authorization. The consensus node is mainly responsible for maintaining the blockchain network and verifying the validity of the proof in the private transaction. The method can be operated in a blockchain environment without depending on a trusted centralized settlement mechanism, each link of transaction writes cryptographic promises and zero knowledge proofs into the blockchain, and can fully utilize the non-falsifiable and publicly verifiable properties of the blockchain data to realize comprehensive verification of transaction privacy