Distributed key recovery method and system and medium

Abstract

The invention discloses a distributed key recovery method and system and a medium. The key recovery method comprises the following steps: constructing a secret value according to a key; determining secret value segmentation prime numbers, and respectively calculating shares corresponding to the prime numbers by combining the secret values; distributing the prime numbers and the corresponding shares to different servers; and when the key needs to be recovered, obtaining the prime number and the corresponding share stored in each server based on authentication to realize key recovery. According to the invention, the security of the secret key is maintained through the plurality of servers together, the trust demand for any single entity is reduced, and the problems of single point failure and trust in the prior art can be effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and more specifically to a distributed key recovery method, system and medium. Background Art

[0002] The key is the most important part of the encryption system, which directly determines the security of encryption. Once the key is lost or damaged, the corresponding encrypted data will be unreadable.

[0003] However, in actual applications, key loss often occurs due to hardware failure, software error, user misoperation, etc., and malicious attackers may also try to steal or destroy keys to achieve illegal access. Therefore, it is crucial to provide an effective key recovery solution while ensuring key security.

[0004] At present, key recovery is mainly achieved through key escrow, that is, a trusted third party (such as a key escrow service) is used to save the user's key backup; when key recovery is needed, the user can obtain the key from the third party by verifying the identity. The advantage of this method is that it can effectively deal with the problem of key loss, but it also has the risk of single point failure and the need to trust the third party.

[0005] Therefore, how to overcome the above-mentioned defects is a problem that those skilled in the art need to solve urgently. Summary of the invention

[0006] In view of this, the present invention provides a distributed key recovery method, system and medium, which mainly divides the key into multiple parts and distributes them to different participants through distributed technology and cryptographic principles, which not only enhances the fault tolerance of the system, but also reduces the dependence on a single entity.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] On the one hand, the present application provides a distributed key recovery method, the steps comprising:

[0009] Construct a secret value based on the key;

[0010] Determine the prime numbers that divide the secret value, and calculate the shares corresponding to each prime number based on the secret value;

[0011] Distribute each prime number and corresponding share to different servers;

[0012] When the key needs to be restored, the prime numbers and corresponding shares stored in each server are obtained based on authentication to achieve key recovery.

[0013] Preferably, constructing a secret value according to the key includes:

[0014] A secret value is determined based on the user's initial prime number m0 and share b0, and the secret value has the key as the high bit.

[0015] As a preferred method, determine the prime numbers that divide the secret value, and calculate the corresponding shares of each prime number in combination with the secret value. The calculation formula is:

[0016]

[0017] Where s is the secret value, m i represents the segmentation prime number, b i Represents the segmentation prime number m i The corresponding share, n represents the number of split prime numbers.

[0018] This application can effectively protect the secret value s by using the share calculated by modular operation;

[0019] As a preference, the split prime number m i The following relationship is satisfied to ensure that all delegate servers and users participate in the recovery of the secret s:

[0020]

[0021] In the formula, n represents the number of segmentation primes.

[0022] Preferably, the prime numbers and corresponding shares stored in each server are obtained based on the authentication to realize key recovery, including:

[0023] According to the prime number m j The key recovery parameter tuple (M, M) is calculated as follows j , M j -1 ); the prime number m j Including the initial prime number m0 and the prime number m stored in each server i ;

[0024] ;

[0025] Based on the recovery parameter tuple (M, M j , M j -1 ) and share b j Determine the secret value to be recovered according to the following formula ; the share b j Including the initial share b0 and the prime number m stored in each server i The corresponding share b i ;

[0026]

[0027] extract Middle and high positions, determine the key.

[0028] On the other hand, the present application provides a distributed key recovery system, which applies the distributed key recovery method as described above, and specifically includes:

[0029] A secret value generating unit, used for constructing a secret value according to a key;

[0030] A distributed key generation unit, used to determine the prime numbers that divide the secret value, and calculate the shares corresponding to each prime number in combination with the secret value;

[0031] A distributed key distribution unit, used to distribute each prime number and corresponding share to different servers;

[0032] The key recovery unit is used to obtain the prime numbers and corresponding shares stored in each server based on authentication to achieve key recovery when the key needs to be recovered.

[0033] Preferably, the distributed key generation unit randomly generates a segmentation prime number according to the following formula:

[0034]

[0035] Preferably, the distributed key generation unit calculates the shares corresponding to each prime number according to the following formula:

[0036]

[0037] Where s is the secret value, m i represents the segmentation prime number, b i Represents the segmentation prime number m i The corresponding share, n represents the number of split prime numbers.

[0038] On the other hand, the present invention also provides a storage medium having stored thereon one or more programs readable by a computing device, wherein the one or more programs include instructions which, when executed by the computing device, enable the computing device to perform the distributed key recovery method as described above.

[0039] The present invention discloses a distributed key recovery method, system and medium. Compared with the prior art, the present invention no longer completely relies on a single trusted third party, but instead uses multiple servers to jointly maintain the security of the key, thereby reducing the need for trust in any single entity.

[0040] At the same time, identity authentication when recovering keys effectively prevents unauthorized access and key theft.

[0041] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0042] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0044] Figure 1 This is a flow chart of the distributed key recovery method provided by the present invention. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0047] Embodiment 1:

[0048] like Figure 1 The embodiment of the present invention discloses a distributed key recovery method, which not only solves the single point failure and trust problems in the prior art through innovative key construction, segmentation and recovery methods, but also introduces higher security and efficiency, and has significant practical value and broad application prospects.

[0049] Please refer to the key recovery steps for this application Figure 1 Specifically include:

[0050] S1. Construct a secret value based on the key.

[0051] This application determines the secret value based on the user's initial prime number and share, and the secret value uses the key key as the high bit. That is, if the user's initial prime number is m0, then the user's share b0=s mod m0 must be satisfied, where b0 is some characteristic value of the user or a string of unforgettable numbers to facilitate the subsequent recovery of the key, and s is the secret value. S can be regarded as the concatenation of the key key and s0. The arithmetic operation formula is s=key*10^m+s0, where m represents the number of bits to shift the key left to ensure the normal concatenation of key and s0.

[0052] The purpose of this application is to calculate a low-order s0, and after splicing it with the high-order key key, obtain a secret value s that satisfies b0=s mod m0.

[0053] S2. Determine the prime number m for dividing the secret value i , combined with the secret value s, calculate the corresponding share b of each prime number according to the following formula i ;

[0054]

[0055] In the formula, 1≤i≤n.

[0056] S3, distributing each prime number and the corresponding share to different servers for storing the corresponding user's share;

[0057] That is, the user will calculate the n shares b1, b2, ..., b n and corresponding prime numbers m1,m2,...,m n The data are secretly sent to n servers in the system, and the servers save the shares and prime numbers in the database;

[0058] In this embodiment, when n servers are needed to recover the key, each server needs a prime number m that splits s. i , and satisfy:

[0059]

[0060] In the formula, n represents the number of segmentation primes.

[0061] S4. When the key needs to be restored, the prime numbers and corresponding shares stored in each server are obtained based on identity authentication, and the secret s is calculated and the key is further obtained to complete the secure recovery of the key.

[0062] In this embodiment, the user can communicate with n servers in the system and complete two-way authentication through personal biometrics or other information to ensure the security and reliability of the n servers, so that the server can accurately send the corresponding key share to the user during the subsequent recovery process.

[0063] In one embodiment, the user first determines whether the key is lost. If not, encryption and decryption are performed normally. If the key is accidentally lost, the key is recovered according to the following steps;

[0064] First, send verification information to n servers in the system. After verification, the server will send n shares b1, b2, ..., b n and corresponding prime numbers m1,m2,...,m n Send back to the user;

[0065] The user uses n shares b1, b2, ..., b n and corresponding prime numbers m1,m2,...,m n And the user's initial share b0 and prime number m0 execute:

[0066]

[0067] In the formula, represents the recovered secret value, b j represents the jth segmentation prime number m j The corresponding share, and

[0068] ;

[0069] In this embodiment, the initial share b0 and the prime number m0 are stored at the user end.

[0070] Further, the calculated value Cut off the low-order s0 to get the required key.

[0071] In an exemplary implementation, assuming that the user needs to store the key key=123 securely, and the user wants his prime number to be 71 and the share to be 66, then a secret s=12349 can be constructed to satisfy 12349mod71=66;

[0072] Assuming there are two servers to protect the key, set the prime numbers for the two servers to 11 and 17, so that 11*17*71=13277≥12349;

[0073] The user sends a communication request to the two servers in the system and uses personal biometrics and other information to complete two-way authentication with the servers in the system to ensure that the two servers are safe and reliable and that the servers accurately send the corresponding key shares to the user during the subsequent recovery process;

[0074] The user calculates the shares for the two servers in the system as follows: 12349mod11=7, 12349mod17=7. The user secretly sends (7,11) to the first server and (7,17) to the second server. The servers save these data respectively.

[0075] The user determines whether the key is lost. If the key is not lost, encryption and decryption are performed normally; if it is accidentally lost, key recovery is performed; first, verification information is sent to the two servers in the system. After verification, the first server sends (7,11) to the user, and the second server sends (7,17) to the user;

[0076] The user uses (66, 71), (7, 11), (7, 17) to calculate:

[0077]

[0078] The calculated value Cut off the low-order s0 to get the required secret key key=123.

[0079] The present invention realizes secure storage of keys by constructing secret values ​​by users and using distributed storage, and realizes secure use of keys by using biometric features of users. The present invention can be applied to key recovery or key update modules of various ciphertext systems, effectively reducing the difficulty of users in retrieving keys after losing keys of ciphertext systems, and further reducing the risk of illegal use of data.

[0080] Embodiment 2:

[0081] The present application provides a distributed key recovery system, which applies the distributed key recovery method as described above, and specifically includes:

[0082] A secret value generating unit, used for constructing a secret value according to a key;

[0083] A distributed key generation unit, used to determine the prime numbers that divide the secret value, and calculate the shares corresponding to each prime number in combination with the secret value;

[0084] A distributed key distribution unit, used to distribute each prime number and corresponding share to different servers;

[0085] The key recovery unit is used to obtain the prime numbers and corresponding shares stored in each server based on authentication to achieve key recovery when the key needs to be recovered.

[0086] The above-mentioned distributed key recovery system of the present invention has the same implementation principle and technical effects as those of the above-mentioned distributed key recovery method embodiment. For the sake of brief description, parts not mentioned in this embodiment can be referred to the corresponding contents in the above-mentioned method embodiment, and will not be repeated here.

[0087] Embodiment 3:

[0088] An embodiment of the present invention also provides a storage medium on which one or more programs readable by a computing device are stored. The one or more programs include instructions. When the instructions are executed by the computing device, the computing device executes a distributed key recovery method in Example 1.

[0089] Examples of computer-readable storage media include: read-only memory (ROM), random-access programmable read-only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random-access memory (RAM), dynamic random-access memory (DRAM), static random-access memory (SRAM), flash memory, non-volatile memory, CD-ROM, DVD-ROM, Blu-ray or optical disk storage, hard disk drive (HDD), solid-state drive (SSD), card-type memory (such as a multimedia card, a secure digital (SD) card, or an extreme digital (XD) card), magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state disk, and any other device configured to store a computer program and any associated data, data files, and data structures in a non-transitory manner and provide the computer program and any associated data, data files, and data structures to a processor or computer so that the processor or computer can execute the computer program. The computer program in the above-mentioned computer-readable storage medium can be executed in an environment deployed in a computer device such as a client, a host, an agent device, a server, etc. In addition, in one example, the computer program and any associated data, data files, and data structures are distributed on a networked computer system or a cloud platform, so that the computer program and any associated data, data files, and data structures are stored, accessed, and executed in a distributed manner by one or more processors or computers.

[0090] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems or computer program products, etc. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0091] It should be noted that the word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention can be implemented by means of hardware comprising several distinct components, and by means of a suitably programmed computer.

[0092] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0093] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A distributed key recovery method, characterized in that: Construct a secret value based on the key; Determine the prime numbers that divide the secret value, and calculate the shares corresponding to each prime number based on the secret value; Distribute each prime number and corresponding share to different servers; When the key needs to be restored, the prime numbers and corresponding shares stored in each server are obtained based on authentication to achieve key recovery.

2. The key recovery method according to claim 1, characterized in that: A secret value is determined based on the user's initial prime number m0 and share b0, and the secret value has the key as the high bit.

3. The key recovery method according to claim 2, characterized in that: Determine the prime numbers that divide the secret value, and calculate the corresponding shares of each prime number based on the secret value. The calculation formula is: ； Where s is the secret value, m i represents the segmentation prime number, b i Represents the segmentation prime number m i The corresponding share, n represents the number of split prime numbers.

4. The key recovery method according to claim 3, characterized in that: Cutting prime number m i Satisfies the following relationship: 。 5. The key recovery method according to claim 2, characterized in that: Based on the authentication, the prime numbers and corresponding shares stored in each server are obtained to realize key recovery, including: According to the prime number m j The key recovery parameter tuple (M, M) is calculated as follows j , M j -1 ); the prime number m j Including the initial prime number m0 and the prime number m stored in each server i ,and; ； Based on the recovery parameter tuple (M, M j , M j -1 ) and share b j Determine the secret value to be recovered according to the following formula ; the share b j Including the initial share b0 and the prime number m stored in each server i The corresponding share b i ; ； is the recovered secret value, j is the prime number m j and the corresponding share b j The index of Extracting Secret Values Middle and high positions, determine the key.

6. A distributed key recovery system, characterized in that: A distributed key recovery method according to any one of claims 1 to 5 is applied, wherein the system comprises: A secret value generating unit, used for constructing a secret value according to a key; A distributed key generation unit, used to determine the prime numbers that divide the secret value, and calculate the shares corresponding to each prime number in combination with the secret value; A distributed key distribution unit, used to distribute each prime number and corresponding share to different servers; The key recovery unit is used to obtain the prime numbers and corresponding shares stored in each server based on authentication to achieve key recovery when the key needs to be recovered.

7. The key recovery system according to claim 6, characterized in that: The distributed key generation unit randomly generates the segmentation prime number according to the following formula: ； In the formula, m0 is the initial prime number, n represents the number of split prime numbers, and m i Indicates that the split prime number s is a secret value.

8. The key recovery system according to claim 6, characterized in that: The distributed key generation unit calculates the shares corresponding to each prime number according to the following formula: ； Where s is the secret value, m i represents the segmentation prime number, b i Represents the segmentation prime number m i The corresponding share, n represents the number of split prime numbers.

9. A storage medium having stored thereon one or more programs readable by a computing device, characterized in that: The one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform a distributed key recovery method as described in any one of claims 1-5.

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