An anonymous reputation building method

Abstract

A method for establishing an anonymous reputation includes: initializing a blockchain operating system; generating a private key and pseudonym on the user side; generating a reputation token and serial number on the user side; uploading to the blockchain; consensus node verification; and updating reputation. This method invalidates the reputation token after the user completes interaction with another entity and requires the user to retrieve a new reputation token from the blockchain network. The new reputation token has already been updated before retrieval, thereby forcing a reputation update. This mechanism ensures timely and accurate updates of user reputations, resolving the issue of selective user reputation updates in traditional decentralized reputation systems. By hiding the reputation token's serial number, the verification server cannot obtain subsequent usage scenarios of the reputation token when assisting with reputation updates, thereby enhancing user privacy.

Description

Technical Field

[0001] The present invention relates to the field of network security technology, and in particular to an anonymous decentralized reputation building method. Background Art

[0002] Reputation is a blockchain-based mechanism used to assess and record the reputation and trustworthiness of participants within a blockchain network. It serves as a crucial social governance tool within the blockchain community, promoting honest behavior among participants, preventing malicious activity, and improving overall network security. Users can choose entities with higher reputations to interact with, thereby ensuring network reliability and security. An increasing number of systems and applications are incorporating reputation mechanisms to address trust issues between entities and ensure user and network security.

[0003] In traditional centralized platforms, the centralized servers that coordinate all communications are overly powerful. Once compromised, this server could lead to the leakage of sensitive user information. Therefore, traditional centralized system structures are vulnerable. To overcome the shortcomings of centralized platforms, decentralized platforms have attracted widespread attention in the industry. Decentralized platforms store reputation-related data on a blockchain, allowing any user to publicly verify the reputation of others by accessing the blockchain. However, some decentralized reputation systems have shortcomings in data privacy protection, failing to conceal user identities and ensuring accurate reputation updates. Tassos Dimitriou proposed a decentralized reputation structure and system that can guarantee user privacy, but cannot guarantee accurate reputation updates every time. Wu et al. proposed a privacy-focused verification protocol and designed a smart contract-enforced reputation evaluation model, but each use of the smart contract is costly.

[0004] While existing decentralized reputation platforms can protect user privacy to a certain extent, they still have many shortcomings. Due to the protection of anonymity, users can choose to update their reputations with higher ratings, which is undoubtedly unfair to other honest entities. Furthermore, the reputation update cycle on the blockchain is long and inefficient. Therefore, it is necessary to improve the reputation structure to ensure user privacy while enforcing reputation updates and improving update efficiency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an anonymous reputation building method that enhances user privacy protection, improves system efficiency, and encourages users to behave well.

[0006] The technical solution adopted to solve the above technical problems is: an anonymous reputation building method, including the following steps:

[0007] Step 1. Initialize the blockchain operating system

[0008] Input a security parameter l and output a multiplication cyclic group G1 with a large prime number q as the order. The generator of the multiplication cyclic group G1 is g, and the elements in the multiplication cyclic group G1 are h1, h2, h3, where r1, r2, r3 are random numbers;

[0009] Define a collision-resistant pseudorandom function PRF sk (x), sk is the private key;

[0010] Step 2. The user generates a private key and pseudonym

[0011] The user terminal selects a random number as the private key sk and uses the private key sk to generate the pseudonym pse;

[0012] Step 3. The user generates a reputation token and serial number

[0013] The user terminal initializes the reputation value v, selects random numbers s and r′, and generates a reputation token rep and a serial number sn; the reputation token rep is The serial number sn is sn:=PRF sk (s);

[0014] Step 4. Upload the blockchain

[0015] The user generates a zero-knowledge proof π min t , proves the correctness of the reputation token and will contain the reputation token rep and the proof π mint The transaction order is uploaded to the blockchain;

[0016] Step 5. Consensus Node Verification

[0017] The consensus node of the blockchain verifies the proof π in the transaction order min t Is it correct? If so, the reputation token rep is submitted to the Merkle tree. At this point, the user can interact with other entities.

[0018] Step 6. Reputation Update

[0019] Step 6.1. After interacting with other entities, the user receives the reputation evaluation v of other entities r , disclose a serial number that does not appear in the cancellation serial number list, at which point the original reputation token rep held by the user becomes invalid;

[0020] Step 6.2. The user reconstructs the reputation token rep re , and give the reconstruction proof π re Proof of Reconstruction Reputation Token repre The reputation value is the same as the original reputation token rep;

[0021] Step 6.3. The user end converts the original reputation token rep and the reconstructed reputation token rep re and reconstruction proof π re Send to the verification server;

[0022] Step 6.4. Verification server verifies reconstruction proof π re If it is invalid, the verification failure is sent to the user end; if it is valid, the transaction order on the blockchain is matched according to the original reputation token rep, and the original reputation evaluation v of the user end is found. r ;

[0023] Step 6.5. Verify that the server evaluates v based on the original reputation r according to Get a promise CM r , where r″′ and β are random numbers, and the new reputation token rep is obtained new =rep re CM r , and finally generate a new transaction order tx up Upload to blockchain;

[0024] Step 6.6. The client obtains random numbers r″′, β, and v from the blockchain r , restore the new reputation token rep new , get the new serial number sn new , the user can prove that the reputation token is stored in the Merkle tree child node.

[0025] As a preferred technical solution, the pseudonym pse in step 2 is: r is a random number.

[0026] As a preferred technical solution, the proof π described in step 4 min t for:

[0027]

[0028] Where zkSNAPK{·} is an arbitrarily chosen concise non-interactive zero-knowledge proof;

[0029] The transaction order is:

[0030] tx min t := <pse,rep,v,s,π min t >

[0031] Where tx mint It's a transaction order.

[0032] As a preferred technical solution, the reputation token rep reconstructed in step 6.2 re For: rep re =g r″ h1 sk h2 s′ h3 v , r″ and s′ are random numbers; the reconstruction proves π re for:

[0033]

[0034] sn=PRF sk (s)∧rep∈The merkle tree whose root node is rt}.

[0035] As a preferred technical solution, the new reputation token rep in step 6.6 new for: The new serial number sn new For: sn new =PRF sk (s′+β), s′ is a random number.

[0036] The beneficial effects of the present invention are as follows:

[0037] This invention achieves a mandatory reputation update by invalidating a user's reputation token after completing an interaction with another entity and requiring the user to retrieve a new reputation token from the blockchain network. This new reputation token has already been updated before it is retrieved. This mechanism ensures timely and accurate updates to user reputations, resolving the issue of selective user updates in traditional decentralized reputation systems.

[0038] By hiding the serial number of the reputation token, the present invention prevents the verification server from obtaining subsequent usage scenarios of the reputation token when assisting in updating the reputation, thereby enhancing user privacy protection.

[0039] The present invention assists in updates through the verification server, and only needs to append a single block to the blockchain to end the update cycle, which significantly improves the update efficiency. Existing decentralized reputation platforms usually need to append multiple blocks to the blockchain to end the update cycle when updating reputation. Therefore, the present invention solves the problems of long update cycles and low efficiency of traditional decentralized reputation platforms.

[0040] This invention incentivizes users to maintain honest behavior in a decentralized network, making it easier for entities with higher reputation values ​​in the system to gain the trust of other entities. This mechanism encourages users to continuously demonstrate good behavior to maintain and improve their reputation values. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and examples, but the present invention is not limited to the following embodiments.

[0043] exist Figure 1 In this embodiment, an anonymous reputation building method includes the following steps:

[0044] Step 1. Initialize the blockchain operating system

[0045] Input a security parameter l and output a multiplication cyclic group G1 with a large prime number q as the order. The generator of the multiplication cyclic group G1 is g, and the elements in the multiplication cyclic group G1 are h1, h2, h3, where r1, r2, r3 are random numbers;

[0046] Define a collision-resistant pseudorandom function PRF sk (x), used to generate a serial number, where sk is the private key;

[0047] Step 2. The user generates a private key and pseudonym

[0048] The user terminal selects a random number as the private key sk and uses the private key sk to generate the pseudonym pse. r is a random number used to protect the user's identity anonymity;

[0049] Step 3. The user generates a reputation token and serial number

[0050] The user initializes the reputation value v, selects random numbers s and r′, and generates the reputation token rep. Serial number sn, sn: = PRF sk (s);

[0051] Step 4. Upload the blockchain

[0052] The user generates a zero-knowledge proof π min t , proving the correctness of reputation tokens, zkSNAPK{·} is an arbitrarily chosen concise non-interactive zero-knowledge proof that proves π min t Generate transaction order tx min t Upload to blockchain, txmin t := <pse,rep,v,s,π min t >

[0053] Step 5. Consensus Node Verification

[0054] Blockchain nodes verify the proof π in the transaction min t Is it correct? If so, the reputation token rep is submitted to the Merkle tree. At this point, the user can interact with other entities.

[0055] Step 6. Reputation Update

[0056] Step 6.1. After interacting with other entities, the user receives the reputation evaluation v of other entities r , disclose a serial number that does not appear in the cancellation serial number list, at which point the original reputation token rep held by the user becomes invalid;

[0057] Step 6.2. The user reconstructs the reputation token rep re , r″ and s′ are random numbers, and the reconstruction proof π is given re Proof of Reconstruction Reputation Token rep re The reputation value of the original reputation token rep is the same as the reconstruction proof π re for:

[0058]

[0059] Step 6.3. The user end converts the original reputation token rep and the reconstructed reputation token rep re and reconstruction proof π re Send to the verification server;

[0060] Step 6.4. Verification server verifies reconstruction proof π re If it is invalid, the verification failure is sent to the user end; if it is valid, the transaction order on the blockchain is matched according to the original reputation token rep, and the original reputation evaluation v of the user end is found. r ;

[0061] Step 6.5. Verify that the server evaluates v based on the original reputation r according to Get a promise CM r , where r″′ and β are random numbers, and the new reputation token rep is obtained new =rep re CM r , and finally generate a new transaction order tx up Upload to blockchain;

[0062] Step 6.6. The client obtains random numbers r″′, β, and v from the blockchain r , restore the new reputation token rep new , Get the new serial number sn new , sn new =PRF sk (s′+β), the user can prove that the reputation token is stored in the Merkle tree child node.

Claims

1. A method for building an anonymous reputation, characterized in that: The following steps are involved: Step 1. Initialize the blockchain operating system Input a security parameter l and output a multiplication cyclic group G1 with a large prime number q as the order. The generator of the multiplication cyclic group G1 is g, and the elements in the multiplication cyclic group G1 are h1, h2, h3, where r1, r2, r3 are random numbers; Define a collision-resistant pseudorandom function PRF sk (x), sk is the private key; Step 2. The user generates a private key and pseudonym The user terminal selects a random number as the private key sk and uses the private key sk to generate the pseudonym pse; Step 3. The user generates a reputation token and serial number The user terminal initializes the reputation value v, selects random numbers s and r′, and generates a reputation token rep and a serial number sn; the reputation token rep is The serial number sn is sn:=PRF sk (s); Step 4. Upload the blockchain The user generates a zero-knowledge proof π min t , used to prove the correctness of the reputation token and will contain the reputation token rep and the proof π min t The transaction order is uploaded to the blockchain; Step 5. Consensus Node Verification The consensus node of the blockchain verifies the proof π in the transaction order min t Is it correct? If so, the reputation token rep is submitted to the Merkle tree. At this point, the user can interact with other entities. Step 6. Reputation Update Step 6.

1. After interacting with other entities, the user receives the reputation evaluation v of other entities r , disclose a serial number that does not appear in the cancellation serial number list, at which point the original reputation token rep held by the user becomes invalid; Step 6.

2. The user reconstructs the reputation token rep re , and give the reconstruction proof π re Proof of Reconstruction Reputation Token rep re The reputation value is the same as the original reputation token rep; Step 6.

3. The user end converts the original reputation token rep and the reconstructed reputation token rep re and reconstruction proof π re Send to the verification server; Step 6.

4. Verification server verifies reconstruction proof π re If it is invalid, the verification failure is sent to the user end; if it is valid, the transaction order on the blockchain is matched according to the original reputation token rep, and the original reputation evaluation v of the user end is found. r ; Step 6.

5. Verify that the server evaluates v based on the original reputation r according to Get a promise CM r , where r″′ and β are random numbers, and the new reputation token rep is obtained new =rep re CM r , and finally generate a new transaction order tx up Upload to blockchain; Step 6.

6. The client obtains random numbers r″′, β, and v from the blockchain r , restore the new reputation token rep new , get the new serial number sn new , the user can prove that the reputation token is stored in the Merkle tree child node.

2. The anonymous reputation building method according to claim 1, characterized in that: The pseudonym pse in step 2 is: r is a random number.

3. The anonymous reputation building method according to claim 2, characterized in that: Prove π as described in step 4 min t for: Where zkSNAPK{·} is an arbitrarily chosen concise non-interactive zero-knowledge proof; The transaction order is: tx min t :=<pse,rep,v,s,π min t > Where tx min t It's a transaction order.

4. The anonymous reputation building method according to claim 1, characterized in that: Reconstruct the reputation token rep as described in step 6.2 re For: rep re =g r″ h1 sk h2 s h3 v , r″ and s′ are random numbers; the reconstruction proves π re for:

5. The anonymous reputation building method according to claim 4, characterized in that: The new reputation token rep described in step 6.6 new for: The new serial number sn new For: sn new =PRF sk (s′+β), s′ is a random number.

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