Delay function and zero-knowledge based storage space attestation method, device and medium

Abstract

The application discloses a storage space proving method based on a delay function and zero knowledge, and relates to the technical field of computer security. The method comprises the following steps: a storage party creates a table according to an actual storage space size and a verifiable delay function, and records a one-to-one correspondence between input and output of the verifiable delay function on the table; a verifier randomly generates a challenge as a target output of the verifiable delay function; the storage party finds a target input corresponding to the target output from the table and sends the target input to the verifier; the storage party generates zero knowledge proof data according to the target input and the target output and sends the zero knowledge proof data to the verifier; the verifier verifies according to the target input and the zero knowledge proof data and obtains a verification result; and whether the storage party has the corresponding storage space is determined according to the verification result. The application further discloses an electronic device and a computer readable storage medium, and the storage party can be proved to have a certain size of storage space.

Description

Technical Field

[0001] This invention relates to the field of data processing technology, and in particular to a method, device, and medium for proving storage space based on delay functions and zero knowledge. Background Technology

[0002] With the increasing demand for data storage outsourcing services in the era of big data, the trust issue between clients and storage providers urgently needs to be addressed. Data storage outsourcing services generally involve two roles: clients with storage needs and storage providers with a certain amount of physical storage. The storage provider first generates a storage space certificate for a specific storage space. Only after the storage space certificate is verified can the client trust that the storage provider has the ability to complete the storage task.

[0003] Previous cloud storage solutions did not require storage providers to provide prior proof of their storage capacity. This could lead to trust issues between storage providers and customers, and storage providers might be unable to complete the storage task. For example, a customer might have 100TB of data to store, but the storage provider could only provide 10TB of storage space.

[0004] Chinese invention patent CN114978545B discloses a method and related apparatus for generating cross-chain primitives for heterogeneous consortium blockchains. The method includes: processing cross-chain transactions and auxiliary information using a primitive generation model to obtain cross-chain primitives, wherein the primitive generation model includes a zero-knowledge proof algorithm and a verifiable delay function; and verifying the cross-chain primitives to confirm whether the cross-chain transactions and auxiliary information have been successfully uploaded to the blockchain. The combination of the zero-knowledge proof algorithm and the verifiable delay function effectively protects transaction privacy and prevents privacy leaks. This scheme is not intended to prove the storage space of the storage provider. Summary of the Invention

[0005] In view of this, the purpose of this invention is to propose a storage space proof method based on delay function and zero knowledge, and to provide a protocol that can prove that the storage party does indeed possess a certain amount of storage space.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by this invention is as follows:

[0007] This invention provides a storage space proof method based on delay functions and zero-knowledge, applicable between the storage party and the verifier; it includes the following steps:

[0008] Step 1: The storage party creates a table based on the actual storage space size and the verifiable delay function, and records the one-to-one correspondence between the input and output of the verifiable delay function in the table;

[0009] Step 2: The verifier randomly generates a challenge as the target output of the verifiable delay function;

[0010] Step 3: The storage unit finds the target input corresponding to the target output in the table and sends it to the verifier;

[0011] Step 4: The storage party generates zero-knowledge proof data based on the target input and target output, and sends it to the verifier;

[0012] Step 5: The verifier performs verification based on the target input and zero-knowledge proof data, and obtains the verification result;

[0013] Step 6: Determine whether the storage provider has the corresponding storage space based on the verification results.

[0014] Furthermore, step 1 specifically includes:

[0015] Step 11: Define the verifiable delay function as y = DF n (key0+x, m); where key0 and m represent random parameters, x represents the input of the verifiable delay function, y represents the output of the verifiable delay function, and n represents the length of each binary unit;

[0016] Step 12: Set the specific values ​​of key0, m, and n according to the actual storage space size, and determine the corresponding target verifiable delay function y = DF. n (key0+x, m);

[0017] Step 13: The storage side verifies the delay function y = DF based on the target. n Create a table (key0+x, m) and record the target verifiable delay function y = DF on the table. n Establish a one-to-one correspondence between the different inputs and corresponding outputs of (key0+x, m);

[0018] Step 14: If the target verifies that the maximum output of the delay function is y max This indicates that the storage provider has at least the ability to store (key0+x, m). max The storage space required for ×n bits of data.

[0019] Furthermore, step 2 specifically includes:

[0020] The verifier randomly generates a challenge as the target to verify the delay function y = DF. n The target output is (key0+x, m); where challenge = {y1, y2, ..., y}. k}, y i ∈{0,1} n,i=1,2,…,k;y1,y2,…,y k This represents the corresponding output; k represents the total number of randomly generated challenges, i represents the corresponding number, and y represents the output. i ∈{0,1} n Indicates the i-th output y i It is a binary string composed of multiple binary units of length n.

[0021] Furthermore, step 3 specifically includes:

[0022] Step 31: Within a set delay time t, the storage unit searches the table for the target input result = {x} corresponding to the target output. i |DF n (key0+x i ,m)=y i y i ∈chanllenge};

[0023] Step 32: Send the target input result to the verifier.

[0024] Furthermore, step 4 specifically includes:

[0025] Step 41: Obtain the zero-knowledge proof generation algorithm;

[0026] Step 42: The storage party performs zero-knowledge processing on the numerical values ​​and corresponding relationships of the target input result and the target output challenge based on the zero-knowledge proof generation algorithm to obtain zero-knowledge proof data;

[0027] Step 43: Send the zero-knowledge proof data to the verifier.

[0028] Furthermore, step 5 specifically includes:

[0029] Step 51: Based on the target, the delay function y = DF can be verified. n The threshold (k) of the target input is determined by (key0+x, m) and the total number of randomly generated challenges k;

[0030] Step 52: The verifier compares the target input result with the threshold (k). If |result| ≥ threshold (k), it means that the storage device has found a result that satisfies DF within the set delay time t. n (key0+x i ,m)=y i x i And x i If the quantity is greater than the threshold, proceed to step 53; otherwise, end the process.

[0031] Step 53: Obtain the zero-knowledge verification algorithm;

[0032] Step 54: The verifier performs zero-knowledge verification on the zero-knowledge proof data based on the zero-knowledge verification algorithm and obtains the verification result.

[0033] Furthermore, step 6 includes:

[0034] Step 61: If the zero-knowledge verification determines that the zero-knowledge proof data is valid, it means that the verification result is that the zero-knowledge proof data verification passed, thus proving that the storage party has at least the ability to store (key0+x, m). max The storage space required for ×n bits of data;

[0035] Step 62: If the zero-knowledge verification determines that the zero-knowledge proof data is invalid, it means that the verification result is a failure of the zero-knowledge proof data verification, and the process ends.

[0036] Furthermore, the interval between step 4 and step 5 also includes:

[0037] The first block of data is generated based on the target input and zero-knowledge proof data;

[0038] The first block data is sent to the verification nodes in the blockchain network for verification, and the verification results returned by the verification nodes are received.

[0039] When the verification node returns a successful verification result, the first block data is added to the blockchain for third parties to view and use;

[0040] Following step 54, the following also includes:

[0041] The second block of data is generated based on the verification results obtained after zero-knowledge verification.

[0042] The second block data is added to the blockchain for third parties to view and use.

[0043] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements a memory space proof method based on a delay function and zero knowledge as described above.

[0044] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements a storage space proof method based on a delay function and zero knowledge as described above.

[0045] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0046] 1. A protocol is proposed that can be used to prove that a certain amount of storage space is available.

[0047] 2. Combine verifiable delay functions and zero-knowledge proofs to complete the corresponding protocol.

[0048] 3. The verification scheme assigns the verification work to a specific verifier, saving the computing power of other verifiers.

[0049] 4. Based on the two-factor authentication, the blockchain only needs to verify the brief proof in the two-factor authentication, making the computation more user-friendly. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is an execution flowchart of a storage space proof method based on delay functions and zero knowledge provided in an embodiment of the present invention.

[0052] Figure 2 This is a schematic diagram of an electronic device provided in an embodiment of the present invention.

[0053] Figure 3 This is a schematic diagram of a computer-readable storage medium provided in an embodiment of the present invention. Detailed Implementation

[0054] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the invention. Similarly, the following embodiments are only some, not all, embodiments of the present invention, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please see Figure 1This invention discloses a storage space proof method based on delay functions and zero-knowledge proofs. This method is applied between a storage party (the prover) and a verifier (the verifier who verifies whether the storage party possesses sufficient storage space). The techniques employed primarily include verifiable delay functions and zero-knowledge proofs. Verifiable delay functions are a type of cryptographic algorithm that is time-consuming in forward computation but fast in reverse computation, possessing properties of delay, unique output, and verifiability. Zero-knowledge proofs demonstrate the correctness of a statement without revealing the original information, offering advantages such as data privacy protection, non-interaction, and short proof length. Storage space proofs involve the prover demonstrating to others that they possess sufficient storage space.

[0056] The method specifically includes the following steps:

[0057] Step 1: The storage provider creates a table based on the actual storage space size and the verifiable delay function, recording the one-to-one correspondence between the input and output of the verifiable delay function in the table. This one-to-one correspondence allows the unique corresponding input to be determined given the output value, providing a theoretical basis and evidence for subsequent challenges.

[0058] In this embodiment, step 1 specifically includes:

[0059] Step 11: Define the verifiable delay function as y = DF n (key0+x, m) is a mapping from n bits to n bits, meaning both its input and output are binary strings of length n. The verifiable delay function here is a special type of function and can have different choices; we'll use DF for a consistent approach. n The expression is as follows: where key0 and m represent random parameters (random numbers of n bits), x represents the input of the verifiable delay function, y represents the output of the verifiable delay function, and n represents the length of each binary unit.

[0060] Step 12: Set the specific values ​​of key0, m, and n according to the actual storage space size, and determine the corresponding target verifiable delay function y = DF. n (key0+x, m); By adjusting the size of n, the storage space required for proof can be significantly controlled, while by adjusting the sizes of key0 and m, the storage space required for proof can be slightly controlled. This is because the specific values ​​of key0, m, and n are closely related to the storage space size; once the actual storage space size is determined, the closest values ​​of key0, m, and n can be determined accordingly.

[0061] Step 13: The storage side verifies the delay function y = DF based on the target.n Create a table (key0+x, m) and record the target verifiable delay function y = DF on the table. n This table establishes a one-to-one correspondence between the different inputs and outputs of (key0+x, m); it is used to address subsequent challenges.

[0062] Step 14: If the target verifies that the maximum output of the delay function is y max This indicates that the storage provider has at least the ability to store (key0+x, m). max The storage space required for ×n bits of data.

[0063] For example, assuming the values ​​of key0 and m are 0, the target verifiable delay function y = DF n (x), the table is as follows:

[0064] 1 <![CDATA[DF n (1)]]> 2 <![CDATA[DF n (2)]]> ... ... <![CDATA[2 n -1]]> <![CDATA[DF n (2 n -1)]]>

[0065] Maximum output is DF n (2 n When -1), the table description can store (2) n -1)×n bits of data, therefore, this scheme proves that the storage party possesses (2) n The storage space required for -1)×n bits of data. The storage space required varies depending on the value of n, so n can be adjusted to control the size of the storage space needed for proof.

[0066] For example, when n=2, it means that the length of a binary unit is 2. When the input is 1, the corresponding output is 1×n=2, that is, there is only one binary unit, so the binary length is 2 bits. When the input is 2, the corresponding output is 2×n=4, that is, two binary units are concatenated to form a binary string with a binary length of 4 bits. When the input is 3, the corresponding output is 3×n=6, that is, three binary units are concatenated to form a binary string with a binary length of 6 bits. And so on.

[0067] Step 2: The verifier randomly generates a challenge as the target output of the verifiable delay function;

[0068] In this embodiment, step 2 specifically includes:

[0069] The verifier randomly generates a challenge as the target to verify the delay function y = DF. n The target output is (key0+x, m); where challenge = {y1, y2, ..., y}. k}, y i ∈{0,1}n ,i=1,2,…,k;y1,y2,…,y k This represents the corresponding output; k represents the total number of randomly generated challenges, i represents the corresponding number, and y represents the output. i ∈{0,1} n Indicates the i-th output y i It is a binary string composed of multiple binary units of length n.

[0070] Step 3: The storage unit finds the target input corresponding to the target output in the table and sends it to the verifier to complete the first response;

[0071] In this embodiment, step 3 specifically includes:

[0072] Step 31: Within a set delay time t, the storage unit searches the table for the target input result = {x} corresponding to the target output. i |DF n (key0+x i ,m)=y i y i ∈challenge}; Here, the storage side needs to find the target inputs of the target verifiable delay function, which satisfy that its corresponding output is in the challenge data given by the verifier.

[0073] Step 32: Send the target input result to the verifier.

[0074] Step 4: The storage provider generates zero-knowledge proof data based on the target input and target output, and sends it to the verifier to complete the second response. The zero-knowledge proof data is a simplified proof pi after conversion. Using zero-knowledge proof, the storage provider can prove to the verifier that it has completed the corresponding calculation work, saving the verifier most of the verification work and saving time.

[0075] In this embodiment, step 4 specifically includes:

[0076] Step 41: Obtain the zero-knowledge proof generation algorithm;

[0077] Step 42: The storage party performs zero-knowledge processing on the numerical values ​​and corresponding relationships of the target input result and the target output challenge based on the zero-knowledge proof generation algorithm to obtain zero-knowledge proof data;

[0078] Step 43: Send the zero-knowledge proof data to the verifier. Zero-knowledge proofs allow the verifier to believe that the storage device has completed a certain amount of computation, enabling the verifier to quickly verify the data without recalculation. Because verifiable delay functions are slow, zero-knowledge proofs are introduced to speed up the verifier's verification process.

[0079] Step 5: The verifier performs verification based on the target input and zero-knowledge proof data, and obtains the verification result;

[0080] In this embodiment, step 5 specifically includes:

[0081] Step 51: Based on the target, the delay function y = DF can be verified. n The threshold (k) of the target input is determined by (key0+x, m) and the total number of randomly generated challenges k;

[0082] Step 52: The verifier compares the target input result with the threshold (k). If |result| ≥ threshold (k), it means that the storage device has found a result that satisfies DF within the set delay time t. n (key0+x i ,m)=y i x i And x i If the number is greater than the threshold, proceed to step 53; otherwise, end the process; this verification confirms that the storage party has found the majority of y i The original image; for the storage side, it may not be able to find some of the data inputs in the challenge given by the validator, but it is highly likely to find a large number of corresponding inputs. Therefore, a threshold threshold(k) is set so that when the storage side finds a certain number of inputs, it is sufficient, that is, the storage side finds a large number of inputs that satisfy the DF in a short time. n (key0+x i ,m)=y i x i This way, the verifier can trust that the storage provider has pre-stored the corresponding data, meaning that the storage provider has a certain amount of storage space; otherwise, the verifier would not be able to complete the verification in a short time.

[0083] Step 53: Obtain the zero-knowledge verification algorithm;

[0084] Step 54: The verifier performs zero-knowledge verification on the zero-knowledge proof data based on the zero-knowledge verification algorithm, obtains the verification result, and verifies the validity of the zero-knowledge proof data.

[0085] The verification of the zero-knowledge proof was completed based on the zero-knowledge proof data provided in the first and second responses. This part of the proof demonstrates the zero-knowledge proof given in step 2. i Indeed meets DF n (key0+x i ,m)=y i .

[0086] Step 6: Determine whether the storage provider has the corresponding storage space based on the verification results.

[0087] In this embodiment, step 6 includes:

[0088] Step 61: If the zero-knowledge verification determines that the zero-knowledge proof data is valid, it means that the verification result is that the zero-knowledge proof data verification passed, thus proving that the storage party has at least the ability to store (key0+x, m). max The storage space required for ×n bits of data;

[0089] Step 62: If zero-knowledge verification determines that the zero-knowledge proof data is invalid, indicating that the verification result is a failure of the zero-knowledge proof data verification, the process ends. Proving storage space based on verifiable delay functions and zero-knowledge proof technology possesses the properties of delay, unique output, and verifiability. It proves the correctness of a statement without revealing the original information, offering advantages such as protecting data privacy, non-interaction, and short proof length.

[0090] In this embodiment, the step between step 4 and step 5 further includes:

[0091] The first block of data is generated based on the target input and zero-knowledge proof data;

[0092] The first block data is sent to the verification nodes in the blockchain network for verification, and the verification results returned by the verification nodes are received.

[0093] When the verification node returns a successful verification result, the first block data is added to the blockchain for third parties to view and use;

[0094] Following step 54, the following also includes:

[0095] The second block of data is generated based on the verification results obtained after zero-knowledge verification.

[0096] The second block data is added to the blockchain for third parties to view and use; the verified results are directly uploaded to the chain so that other users do not need to perform verification again.

[0097] This scheme divides the response process into two parts. After the first response, the blockchain receives the result from the storage provider, but instead of verifying it, the storage provider completes the verification themselves. This is done by having the storage provider convert the computation of the verification process into verifiable computation, generating a short zero-knowledge proof, and completing the second response. The blockchain then only needs to verify the short proof in the second response. As we know from the analysis of the previous scheme, the first response requires a relatively short response time (setting a delay time t) to ensure that the storage provider has actually stored the data and can respond quickly. The second response, because it requires generating verifiable computation, is more time-consuming; therefore, a relatively long response time can be set to allow the storage provider sufficient time to generate the proof.

[0098] like Figure 2 As shown, this embodiment of the invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described method for proving storage space based on a delay function and zero knowledge.

[0099] like Figure 3 As shown, embodiments of the present invention also provide a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method for proving storage space based on a delay function and zero knowledge.

[0100] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0101] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the methods of various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0102] The above description is only a part of the embodiments of the present invention and does not limit the scope of protection of the present invention. Any equivalent device or equivalent process transformation made based on the content of the present invention specification and drawings, or direct or indirect application in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A storage space proof method based on a delay function and zero knowledge, characterized by, Be applied between the storage party and the verifier; Including the following steps: Step 1, the storage party creates a table according to the actual storage space size and the verifiable delay function, and records the one-to-one correspondence between the input and output of the verifiable delay function on the table; Specifically including: Step 11, define the verifiable delay function as y = DF n ( key 0+ x , m ); wherein, key 0 and m represent random parameters, x represents the input of the verifiable delay function, y represents the output of the verifiable delay function, and n represents the length of each binary unit; Step 12, set according to the actual storage space size key 0, m and n the specific values, determine the value of Target verifiable delay function y = DF n ( key 0 x , m ); Step 13: The storage side verifies the delay function based on the target. y =DF n ( key 0+ x , m Create a table and record the target verifiable delay function on the table. y =DF n ( key 0+ x , m Different inputs and corresponding outputs are used to establish a one-to-one correspondence between the corresponding inputs and outputs; Step 14, if the maximum output of the target verifiable delay function is y max , then the storage party has at least the storage space required to store key 0+ x , m ) max n bits of data; Step 2, the verifier randomly generates a challenge as the target output of the verifiable delay function; Specifically: The verifier randomly generates a challenge challenge as a target verifiable delay function y = DF n ( key x , m ) a target output; wherein, challenge={ y 1, y 2, …, y k}, y i ∈{0,1} n , i=1, 2, …, k; y 1, y 2, …, y k corresponding output; k represents the total number of randomly generated challenges, i represents the corresponding number, y i ∈{0,1} n represents the ith output y i is a binary string composed of a plurality of binary units with a length of n;​ Step 3, the storage party finds the target input corresponding to the target output from the table and sends it to the verifier; Step 4, the storage party generates zero-knowledge proof data according to the target input and the target output and sends it to the verifier; Specifically including: Step 41, obtain a zero-knowledge proof generation algorithm; Step 42, the storage party generates zero-knowledge proof data based on the zero-knowledge proof generation algorithm on the target input and the corresponding relationship between the numerical value of the target output challenge and the numerical value of the target output. result and the corresponding relationship between the numerical value of the target output challenge and the numerical value of the target output. Step 43, send the zero-knowledge proof data to the verifier; Step 5, the verifier verifies according to the target input and the zero-knowledge proof data to obtain a verification result; Specifically including: Step 51, determining a threshold threshold(k) for the target input according to the target verifiable delay function y = DF n ( key 0 x , m ) and the total number k of randomly generated challenges Step 52, the verifier inputs the target result If the number of result ≥ threshold (k), it means that the storage party finds out the DF n ( key 0+ x i , m )= y i The number of x i , and x i is greater than the threshold; go to step 53; otherwise, end the process; Step 53, obtain a zero-knowledge verification algorithm; Step 54, the verifier performs zero-knowledge verification on the zero-knowledge proof data based on the zero-knowledge verification algorithm to obtain a verification result; Step 6, determine whether the storage party has the corresponding storage space according to the verification result. 2.The storage space proof method based on delay function and zero-knowledge according to claim 1, wherein, The step 3 specifically includes: Step 31, the storage party finds the target input corresponding to the target output from the table within the set delay time t result ={ x i DF n ( key 0+ x i , m )= y i , y i ∈chanllenge}; Step 32, sending the target input result to the verifier. 3.The delay function and zero-knowledge based storage space proof method of claim 1, wherein, The step 6 has includes: Step 61, if the zero-knowledge verification determines that the zero-knowledge proof data is valid, it means that the verification result is that the zero-knowledge proof data passes the verification, and it is proved that the storage party at least has the storage space required for storing the data of x n bits. key 0+ x , m ) max x n bits of data Step 62, if the zero-knowledge verification determines that the zero-knowledge proof data is invalid, it means that the verification result is zero-knowledge proof data verification failure, then end the process. 4.The storage space proving method based on delay function and zero-knowledge according to claim 3, wherein, Between the step 4 and the step 5, it also includes: Generate first block data based on the target input and the zero-knowledge proof data; Send the first block data to the verification node in the block chain network for verification, and receive the verification result returned by the verification node; When the verification result returned by the verification node is verification success, add the first block data to the block chain for third party to view and use; After the step 54, it also includes: Generate second block data based on the verification result obtained after the zero-knowledge verification; Add the second block data to the block chain for third party to view and use.

5. An electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to realize the storage space proof method based on delay function and zero-knowledge according to any one of claims 1-4.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to realize the storage space proof method based on delay function and zero-knowledge according to any one of claims 1-4.

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