A cross-chain verification privacy protection method based on a garbled circuit
By applying obfuscation circuits in cross-chain blockchain transactions, generating truth tables and obfuscation tables for information replacement, the problem of information leakage in cross-chain transactions is solved, and privacy protection for cross-chain verification is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG UNIV
- Filing Date
- 2023-09-13
- Publication Date
- 2026-08-04
AI Technical Summary
In cross-chain transactions, the cross-chain transaction information stored on the relay chain is easily accessible to other chains, leading to the leakage of business communication information between users of the source chain and the target chain. Existing technologies cannot effectively protect the privacy data of both parties in the cross-chain transaction.
Cross-chain transaction information is encrypted using obfuscation circuits. While the relay chain verifies the transaction, the obfuscation circuits generate truth tables and obfuscation tables to replace the information, ensuring that the relay chain cannot decrypt the specific content of the cross-chain transaction and can only verify the legality of the transaction.
It protects the privacy data of both parties in the cross-chain transaction verification process, ensuring that information security is not leaked. Even after the cross-chain transaction is completed, the relay chain cannot obtain the user's specific transaction information.
Smart Images
Figure CN117061227B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a cross-chain verification method, specifically a cross-chain verification privacy protection method based on obfuscated circuits. Background Technology
[0002] Different blockchain systems can communicate with each other through cross-chain methods. Cross-chain solutions based on relay chains are one of the mainstream cross-chain solutions at present. Different application chains connect to the relay chain through cross-chain gateways and perform cross-chain operations through the relay chain. The relay chain needs to verify cross-chain transactions to ensure the security and reliability of cross-chain operations.
[0003] However, in this process, cross-chain transaction information fully exposes the business dealings between source chain A and target chain B. Since cross-chain transactions stored on the relay chain can be accessed by other chains, users on source chain A and target chain B may not want their specific business dealings information to be accessed by others. Therefore, a method is needed that can protect the privacy data of both parties in the cross-chain transaction while ensuring that the relay chain can effectively verify the cross-chain transaction. Summary of the Invention
[0004] To address the needs and problems in the background technology, this invention provides a cross-chain verification privacy protection method based on obfuscated circuits. This invention utilizes obfuscated circuits to encrypt data in cross-chain transactions, enabling the protection of cross-chain privacy data between both parties while ensuring effective verification of cross-chain transactions by the relay chain.
[0005] The technical solution of the present invention is as follows:
[0006] Step 1: Under the supervision of each chain, each node of the relay chain generates the logical circuit information of the source chain according to the cross-chain verification rules of the source chain and synchronizes it to the cross-chain gateway where the target chain is located.
[0007] Step 2: The cross-chain gateway where the target chain is located generates a truth table and an obfuscation table based on the source chain's logic circuit information. Then, it sends the obfuscation table to the relay chain and sends the information related to the source chain parameters in the truth table to the cross-chain gateway where the source chain is located.
[0008] Step 3: After a user / organization on the application's source chain calls the cross-chain contract on the application's source chain, a cross-chain event is thrown. The cross-chain gateway where the source chain is located listens for the cross-chain event on the source chain and then obtains the cross-chain transaction information.
[0009] Step 4: After the cross-chain gateways of the source chain and the target chain negotiate the key, they obtain a pair of symmetric keys. The cross-chain gateway of the source chain uses the symmetric key to encrypt the cross-chain transaction information, generating encrypted cross-chain transaction information. The cross-chain gateway of the source chain replaces the symmetric key according to the received truth table, obtains the replaced symmetric key, and sends it to the relay chain along with the encrypted cross-chain transaction information.
[0010] Step 5: The relay chain decrypts the obfuscation table based on the information sent by the cross-chain gateway where the source chain is located, obtains the information verification result C, and forwards it together with the encrypted cross-chain transaction information to the cross-chain gateway where the target chain is located. The cross-chain gateway where the target chain is located verifies the information based on the received information, thereby achieving privacy protection for cross-chain verification.
[0011] In step 1, when the target chain agrees to the source chain performing cross-chain communication with the target chain, the source chain's logic circuit information is generated.
[0012] In step 1, the logic circuit information of the source chain is generated according to the cross-chain verification rules of the source chain, specifically as follows:
[0013] Each node in the relay chain generates a logical circuit according to the cross-chain verification rules of the source chain. After marking the logical circuit, the corresponding circuit marking information is obtained. The logical circuit information is composed of the logical circuit and the corresponding circuit marking information.
[0014] In step 5, the cross-chain gateway where the target chain is located uses a truth table to verify the information verification result C. If the verification result is correct, the symmetric key Key is used to decrypt the encrypted cross-chain transaction information before executing the cross-chain request; otherwise, the symmetric key Key is not used to decrypt the encrypted cross-chain transaction information.
[0015] The circuit labeling information includes the input quantities, output quantities, and intermediate quantities in the logic circuit.
[0016] The beneficial effects of this invention are:
[0017] This invention applies obfuscation circuits to cross-chain transactions in blockchain. By using obfuscation circuits to keep the privacy content involved in cross-chain transactions confidential, the relay chain can verify the transaction normally, but cannot obtain the cross-chain privacy information. However, while completing the cross-chain transaction, it also effectively protects the transaction information of users or institutions. Attached Figure Description
[0018] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation
[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0020] like Figure 1 As shown, the present invention includes the following steps:
[0021] Step 1: Cross-chain gateways such as Pa and Pb each locally generate a pair of public and private keys (KprivA, KpubA) and (KprivB, KpubB). The source chain and the target chain register their respective cross-chain verification rules with the relay chain through their respective cross-chain gateways. Specifically, chain A registers its basic information, the public key of cross-chain gateway Pa, and its cross-chain verification rule Ma with the relay chain through cross-chain gateway Pa. Chain B registers its basic information, the public key of cross-chain gateway Pb, and its cross-chain verification rule Mb with the relay chain through cross-chain gateway Pb. When the target chain agrees to cross-chain communication with the source chain, under the supervision of each chain, each node of the relay chain generates the source chain's logical circuit information according to the source chain's cross-chain verification rules and synchronizes it to the target chain's cross-chain gateway. Furthermore, each node of the relay chain reaches consensus on the logical circuits corresponding to the source chain and the target chain.
[0022] In step 1, the source chain's logic circuit information is generated according to the source chain's cross-chain verification rules, specifically as follows:
[0023] Each node in the relay chain generates a logic circuit according to the cross-chain verification rules of the source chain. After annotating the logic circuit, the corresponding circuit annotation information is obtained. The logic circuit information consists of the logic circuit and the corresponding circuit annotation information. Specifically, the circuit annotation information is composed of the input, output, and intermediate quantities in the logic circuit.
[0024] Step 2: The cross-chain gateway where the target chain resides generates a truth table and an obfuscation table based on the source chain's logic circuit information. It then sends the obfuscation table to the relay chain and the information related to the source chain's parameters from the truth table to the cross-chain gateway where the source chain resides. The truth table contains information related to the source chain's parameters, information related to the relay chain's parameters, and information related to the result. The truth table is a mapping table that replaces real parameters with dummy parameters.
[0025] Step 3: After a user / organization on the application's source chain calls the cross-chain contract on the application's source chain, a cross-chain event is thrown. The cross-chain gateway where the source chain is located listens for the cross-chain event on the source chain and obtains the cross-chain transaction information. The cross-chain transaction information includes the cross-chain transaction payload and the proof information Proof. The cross-chain transaction payload is the call information from chain A to the destination chain B (address information, the contract method called, and parameters), and the proof information Proof is the proof of the validity of the cross-chain transaction.
[0026] Step 4: After the cross-chain gateways of the source chain and the target chain negotiate their keys, they obtain a pair of symmetric keys. The cross-chain gateway of the source chain uses the symmetric key to encrypt the cross-chain transaction information, generating encrypted cross-chain transaction information. The cross-chain gateway of the source chain then replaces the symmetric key with the received truth table, obtaining the replaced symmetric key, and sends it to the relay chain along with the encrypted cross-chain transaction information. Since the relay chain does not know the true value of the symmetric key sent by chain A, it cannot decrypt the information. Other parameters are also encrypted, so no information can be leaked.
[0027] Step 5: The relay chain executes its logic circuit based on the information sent by the cross-chain gateway of the source chain to decrypt the obfuscation table, thereby obtaining the information verification result C. This result C is then forwarded along with the encrypted cross-chain transaction information to the cross-chain gateway of the target chain. The cross-chain gateway of the target chain verifies the information based on the received information, thus achieving privacy protection for cross-chain verification. During the execution of the relay chain's circuit, Enc(data, Key) is decrypted and verified. However, the circuit execution process involves splitting and replacing data, making it impossible to know the meaning of the intermediate calculated results. Therefore, no information leakage occurs. The purpose of executing the circuit is to obtain the information verification result C after decrypting the obfuscation table.
[0028] In step 5, the cross-chain gateway where the target chain is located uses a truth table to verify the information verification result C. If the verification result is correct, the symmetric key Key is used to decrypt the encrypted cross-chain transaction information before executing the cross-chain request; otherwise, the symmetric key Key is not used to decrypt the encrypted cross-chain transaction information.
[0029] Finally, it should be noted that the above embodiments and descriptions are only used to illustrate the technical solutions of the present invention and not to limit it. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the disclosure of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the protection scope of the claims of the present invention.
Claims
1. A cross-chain verification privacy protection method based on obfuscated circuits, characterized in that, Includes the following steps: Step 1: Under the supervision of each chain, each node of the relay chain generates the logical circuit information of the source chain according to the cross-chain verification rules of the source chain and synchronizes it to the cross-chain gateway where the target chain is located. Step 2: The cross-chain gateway where the target chain is located generates a truth table and an obfuscation table based on the source chain's logic circuit information. Then, it sends the obfuscation table to the relay chain and sends the information related to the source chain parameters in the truth table to the cross-chain gateway where the source chain is located. Step 3: After a user / organization on the application's source chain calls the cross-chain contract on the application's source chain, a cross-chain event is thrown. The cross-chain gateway where the source chain is located listens for the cross-chain event on the source chain and then obtains the cross-chain transaction information. Step 4: After the cross-chain gateways of the source chain and the target chain negotiate the key, they obtain a pair of symmetric keys. The cross-chain gateway of the source chain uses the symmetric key to encrypt the cross-chain transaction information, generating encrypted cross-chain transaction information. The cross-chain gateway of the source chain replaces the symmetric key according to the received truth table, obtains the replaced symmetric key, and sends it to the relay chain along with the encrypted cross-chain transaction information. Step 5: The relay chain decrypts the obfuscation table based on the information sent by the cross-chain gateway where the source chain is located, obtains the information verification result C, and forwards it together with the encrypted cross-chain transaction information to the cross-chain gateway where the target chain is located. The cross-chain gateway where the target chain is located verifies the information based on the received information, thereby achieving privacy protection for cross-chain verification.
2. The cross-chain verification privacy protection method based on obfuscated circuits according to claim 1, characterized in that, In step 1, when the target chain agrees to the source chain performing cross-chain communication with the target chain, the source chain's logic circuit information is generated.
3. The cross-chain verification privacy protection method based on obfuscated circuits according to claim 1, characterized in that, In step 1, the logic circuit information of the source chain is generated according to the cross-chain verification rules of the source chain, specifically as follows: Each node in the relay chain generates a logical circuit according to the cross-chain verification rules of the source chain. After marking the logical circuit, the corresponding circuit marking information is obtained. The logical circuit information is composed of the logical circuit and the corresponding circuit marking information.
4. The cross-chain verification privacy protection method based on obfuscated circuits according to claim 1, characterized in that, In step 5, the cross-chain gateway where the target chain is located uses a truth table to verify the information verification result C. If the verification result is correct, the symmetric key Key is used to decrypt the encrypted cross-chain transaction information before executing the cross-chain request; otherwise, the symmetric key Key is not used to decrypt the encrypted cross-chain transaction information.
5. The cross-chain verification privacy protection method based on obfuscated circuits according to claim 3, characterized in that, The circuit labeling information includes the input quantities, output quantities, and intermediate quantities in the logic circuit.