A blockchain distributed timestamp generation method resistant to quantum computer attacks

Abstract

The present invention discloses a blockchain distributed timestamp generation method that is resistant to quantum computer attacks. Specifically, the data generator calculates the hash value of the data information and transmits the hash value to the distributed timestamp server. All distributed timestamp servers sign the same service request and randomly select a distributed timestamp server as the master server. The master server collects all signatures to form a timestamp. A hash binary tree is established through the timestamp. The root hash value of the tree is output to the block of the blockchain as the input of the VDF.Eval algorithm. The result calculated by the VDF.Eval algorithm is verified by the VDF.Verify algorithm to determine whether the generated timestamp is correct. This invention can not only avoid problems such as servers and users colluding to tamper with or forge timestamps, but also solve the problem of quantum attacks on discrete logarithm calculations.

Description

Technical Field

[0001] The present invention belongs to the technical field of blockchain. Background Art

[0002] Blockchains add timestamps when generating blocks, ensuring the authenticity of the data stored in the blockchain. Therefore, timestamps serve the crucial function of proving the existence of block data. They effectively prevent denials of the time at which transaction data was generated, verify the identity of the owner of the transaction data, and, in some cases, prove the existence of important data at a specific point in time.

[0003] Existing centralized timestamp service methods all assume that the timestamp server is secure and trustworthy, an overly strong assumption that is difficult to achieve in reality. Furthermore, a single timestamp server presents the security risk of a single point of failure. Current distributed timestamp solutions require users to maintain real-time communication with all selected issuers to ensure timestamp security, placing an excessive burden on users. Furthermore, with the development of quantum computers, consideration will be required for quantum-resistant blockchain systems, but currently, there is a lack of distributed timestamp methods for such systems. Summary of the Invention

[0004] Purpose of the invention: In order to solve the problems existing in the prior art, the present invention proposes a blockchain distributed timestamp generation method that is resistant to quantum computer attacks.

[0005] Technical solution: The present invention provides a blockchain distributed timestamp generation method that is resistant to quantum computer attacks, specifically comprising the following steps:

[0006] Step 1: The data producer calculates the data information y n The hash value is transmitted to a distributed timestamp server, where there are k distributed timestamp servers; the k distributed timestamp servers sign the data request;

[0007] Step 2: Select one of the distributed timestamp servers as the primary server and the remaining distributed timestamp servers as secondary servers.

[0008] Step 3: The main server collects all signatures and forms a timestamp Stp;

[0009] Step 4: Create a hash binary tree based on the timestamp;

[0010] Step 5: Put the root hash value of the hash binary tree into the i-th block B of the blockchain i Middle, B i Also for the current block;

[0011] Step 6: Use quantum-resistant VDF function to calculate the value of the current block B. i The root hash value root(B i ) and timestamp Stp, verify the timestamp Stp; if the verification passes, it means that the timestamp Stp is correct; otherwise, return to step 1 to regenerate the timestamp.

[0012] Furthermore, the method also includes broadcasting the data information with the correct timestamp to the transaction of the public blockchain, so that everyone can verify the data information and timestamp.

[0013] Furthermore, in step 2, a random algorithm is used to randomly select a master server from the k distributed timestamp servers.

[0014] Furthermore, in step 3, the primary server sorts the received signatures in ascending order of the time sequence of the received secondary server signatures to obtain a timestamp Stp = (S1, S2, .., S j ,..,S k ), where S1 is the signature of the primary server, S j represents the jth signature, j = 1, 2, ..., k, S j =sig j (n,d n ,ID n ,t n ;L n ), sig is the signature algorithm, n is the data information y n The timestamp protocol used, d n Data information y n Hash value, ID n Data information y n Owner's ID; L n For S j The corresponding auxiliary server data information y n Signature time sequence information; L n =H(d n-1 ,ID n-1 ,t n-1 ;H(L n-1 )), where H(.) is the hash function, d n-1 Data information y n-1 Hash value, ID n-1 Data information y n-1 The owner's ID, t n-1 For S j The corresponding auxiliary server data information y n-1 Signature time; data information y n-1 Data information y n The previous data information.

[0015] Furthermore, in step 4, the signature of the primary server is used as the leftmost leaf node of the hash binary tree; the remaining leaf nodes in the hash binary tree are the signatures of the secondary servers, and are arranged from left to right in ascending order of the time when the primary server receives the signature.

[0016] Furthermore, the quantum-resistant VDF function in step 6 is constructed by isologously traversing a supersingular elliptic curve.

[0017] Furthermore, the step 6 is specifically as follows: the quantum-resistant VDF function includes the Eval algorithm and the Verify algorithm; the generated block B i At time t, the previous block B i-1 The root hash value root(B i-1 ), and the value of i is input into the Eval algorithm in the VDF algorithm, and the output of the Eval algorithm includes: t||root(B i )||Stp and proof parameter π;

[0018] Then timestamp Stp, root(B i-1 ), t||root(B i )||Stp and proof parameter π are used as inputs of the Verify algorithm. The Verify algorithm verifies root(B i-1 ) and t||root(B i )||Whether Stp is paired with each other, if so, the timestamp Stp is considered correct.

[0019] Beneficial Effects: This invention designs a quantum-resistant blockchain distributed timestamping method based on a quantum-resistant verifiable delay function. This method overcomes the strong assumption of secure and reliable timestamps in centralized timestamping services and prevents collusion between servers and users to tamper with or forge timestamps. Furthermore, because the VDF's proof parameter π can be computed in parallel, the verification algorithm can complete verification quickly and efficiently, enabling the implementation of data existence proof in a low-cost, parallel manner. After data is generated, a distributed timestamp server constructed using the quantum-resistant verifiable delay function affixes the timestamp. This also avoids real-time communication between users and all signature servers, significantly reducing user communication costs and addressing the single point of failure issue and quantum attacks against discrete logarithm computation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Flowchart of the present invention.

[0021] Figure 2The hash binary tree constructed for the present invention. DETAILED DESCRIPTION

[0022] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] This method provides timestamp services by forming a distributed structure with multiple timestamp servers through quantum-resistant verifiable delay functions (VDF). The process of this method is as follows: Figure 1 shown.

[0024] After data is generated, the data generator calculates a hash value using a hash function. This hash value is then transmitted to a distributed timestamp server. All distributed timestamp servers then sign the same service request and, using a random selection algorithm, randomly select one of the distributed timestamp servers as the master server. The master server collects all signatures to form a timestamp. A binary hash tree is then constructed from the timestamps. The root hash value of the tree is output to the blockchain block as input to the VDF.Eval algorithm. The VDF.Verify algorithm verifies the VDF.Eval algorithm's calculation result to determine the correctness of the generated timestamp. Finally, the timestamp server broadcasts the data, affixed with the correct timestamp, to the blockchain for storage. This ensures that the data existed at a specific point in time, ensuring secure storage of the data within the blockchain.

[0025] The hash values ​​and quantum-resistant VDFs used are as follows:

[0026] 1. Hash value of data: Let H(.) be a secure hash function and the data information be y n ,y n The hash value is H(y n )=d n .

[0027] 2. Quantum-resistant VDF: A VDF is a verifiable evaluation function. However, a quantum-resistant VDF can be constructed by isologously traversing supersingular elliptic curves. It consists of three algorithms: Setup, Eval, and Verify:

[0028] Initialization algorithm Setup(.): Setup(λ,T)→pp:=(ek,vk), which accepts the security parameter λ and the delay parameter T and generates a public parameter pp consisting of the calculation parameter ek and the verification parameter vk.

[0029] Evaluation algorithm Eval(.): Eval(ek,x)→(y,π), which accepts input x and evaluation parameter ek, and produces output y and a proof π.

[0030] Verify(.): Verify(vk,x,y,π)→{accept,reject}, which means accepting vk, x, y, and π, and outputting accept (verification passed) or reject (verification failed).

[0031] The specific method of this embodiment is:

[0032] 1. The data that needs to be timestamped is represented as: y n , its hash value is d n , data information y n The owner's identity is ID n Suppose there are k distributed timestamp servers. A primary server is selected through a random selection algorithm, and the remaining k-1 servers are selected as auxiliary servers. These k timestamp servers provide services for a service request at the same time. The specific steps are as follows:

[0033] 1) Data y n The hash value d n and identity information ID n At the same time, it is sent to k distributed timestamp servers, so that k distributed timestamp servers can check (d n , ID n ) to sign.

[0034] 2) The primary timestamp server is responsible for collecting the signatures of the other k-1 auxiliary servers. The primary server sorts the received signatures in ascending order of the time sequence of the received auxiliary server signatures to obtain the timestamp Stp = (S1, S2, .., S j ,..,S k ); S1 is the signature of the main server, S j Indicates the jth signature in the timestamp, j = 1, 2, ..., k, S j =sig j (n,d n ,ID n ,t n ;L n ), sig is the signature algorithm, n is the data information y n The timestamp protocol used, d n Data information y n Hash value, ID n Data information y n Owner's ID; L n For Sj The corresponding auxiliary server data information y n Signature time sequence information; L n =H(d n-1 ,ID n-1 ,t n-1 ;H(L n-1 )), where H(.) is the hash function, d n-1 Data information y n-1 Hash value, ID n-1 Data information y n-1 The owner's ID, t n-1 For S j The corresponding auxiliary server data information y n-1 Signature time; data information y n-1 Data information y n The previous data information. n It is the hash value d of the previous timestamp data combined with the hash function H. n-1 , identity information ID n-1 , signature time t n-1 and the hash value H(L n-1 ) hashed.

[0035] 3) Create a hash binary tree based on the timestamp, such as Figure 2 As shown, the signature of the primary server is the leftmost leaf node of the hash binary tree, and the remaining leaf nodes in the hash binary tree are the signatures of the secondary servers, and are arranged from left to right in ascending order of the time when the primary server received the signature;

[0036] 2. Transmit the root hash value of the above hash binary tree to B in the constructed blockchain i In the block, each block contains the VDF proof π, the root hash value of the previous block, and other information. Specifically as follows:

[0037] 1) Change root(B i ) as the current block B i The root hash value of the binary tree in B i Also for the i-th block, root(B i-1 ) is the previous block B i-1 The root hash of the binary tree, p is the output of the VDF.

[0038] 2) For block B i , using the root hash root (B i-1 ), as part of the Eval input to calculate the output of VDF: p=VDF(i||t,root(B i-1 ))=t||root(Bi )||Stp,π, where: t is block B i The time of generation, Stp is the timestamp, and π is the proof parameter of VDF.

[0039] 3) Verify the timestamp using the VDF Verify algorithm: Verify the timestamp Stp, the root hash value root of the previous block (B i-1 ), the output value of the Eval algorithm t||root(B i )||Stp and proof parameter π are used as inputs of the Verify algorithm. If the Verify algorithm verifies that root(B i-1 ) and t||root(B i )||Stp are correctly matched with each other, then output accept, indicating that the timestamp Stp is correct. Otherwise, output reject, indicating that the timestamp Stp is incorrect and the data y needs to be recalculated. n timestamp;

[0040] 3. Broadcast all timestamped data to the public blockchain transaction. The transaction is recorded on the blockchain, allowing everyone to verify the data and timestamp. At the same time, due to the tamper-proof and non-repudiation characteristics of the blockchain, no one can modify the timestamp and data on the chain.

[0041] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A blockchain distributed timestamp generation method resistant to quantum computer attacks, characterized in that: The specific steps include: Step 1: The data producer calculates the data information y n The hash value is transmitted to a distributed timestamp server, where there are k distributed timestamp servers; the k distributed timestamp servers sign the data request; Step 2: Select one of the distributed timestamp servers as the primary server and the remaining distributed timestamp servers as secondary servers. Step 3: The main server collects all signatures and forms a timestamp Stp; Step 4: Create a hash binary tree based on the timestamp; Step 5: Put the root hash value of the hash binary tree into the i-th block B of the blockchain i Middle, B i Also for the current block; Step 6: Use quantum-resistant VDF function to calculate the value of the current block B. i The root hash value root(B i ) and timestamp Stp, verify the timestamp Stp; if the verification passes, it means that the timestamp Stp is correct; otherwise, return to step 1 to regenerate the timestamp; The specific steps of step 6 are as follows: the quantum-resistant VDF function includes the Eval algorithm and the Verify algorithm; the generated block B i At time t, the previous block B i-1 The root hash value root(B i-1 ), and the value of i is input into the Eval algorithm in the VDF algorithm, and the output of the Eval algorithm includes: t||root(B i )||Stp and proof parameter π; Then timestamp Stp, root(B i-1 ), t||root(B i )||Stp and proof parameter π are used as inputs of the Verify algorithm. The Verify algorithm verifies root(B i-1 ) and t||root(B i )||Whether Stp is paired with each other, if so, the timestamp Stp is considered correct.

2. A blockchain distributed timestamp generation method resistant to quantum computer attacks according to claim 1, characterized in that: The method also includes broadcasting the data information with the correct timestamp to the transaction on the public blockchain so that everyone can verify the data information and timestamp.

3. The method for generating distributed timestamps for blockchains that are resistant to quantum computer attacks according to claim 1, characterized in that: In step 2, a random algorithm is used to randomly select a master server from the k distributed timestamp servers.

4. The method for generating distributed timestamps for blockchains that are resistant to quantum computer attacks according to claim 1, wherein: In step 3, the primary server sorts the received signatures in ascending order of the time sequence of the received secondary server signatures to obtain a timestamp Stp=(S1, S2, .., S j ,..,S k ), where S1 is the signature of the primary server, S j represents the jth signature, j = 1, 2, ..., k, S j =sig j (n,d n ,ID n ,t n ;L n ), sig is the signature algorithm, n is the data information y n The timestamp protocol used, d n Data information y n Hash value, ID n Data information y n Owner's ID; L n For S j The corresponding auxiliary server data information y n Signature time sequence information; L n =H(d n-1 ,ID n-1 ,t n-1 ;H(L n-1 )), where H(.) is the hash function, d n-1 Data information y n-1 Hash value, ID n-1 Data information y n-1 The owner's ID, t n-1 For S j The corresponding auxiliary server data information y n-1 Signature time; data information y n-1 Data information y n The previous data information.

5. The method for generating distributed timestamps for blockchains that are resistant to quantum computer attacks according to claim 1, wherein: In step 4, the signature of the primary server is used as the leftmost leaf node of the hash binary tree; the remaining leaf nodes in the hash binary tree are the signatures of the secondary servers, and are arranged from left to right in ascending order of the time sequence in which the primary server receives the signature.

6. The method for generating distributed timestamps for blockchains that are resistant to quantum computer attacks according to claim 1, characterized in that: The quantum-resistant VDF function in step 6 is constructed by isologously traversing a supersingular elliptic curve.

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