Dynamic share distribution and secret recovery method and device, equipment and medium

Abstract

The invention discloses a dynamic share distribution and secret recovery method and device, equipment and a medium, and relates to the technical field of information security. If a new participant exists, a share distributor is utilized to select a polynomial with a specific number of times and a random polynomial, based on the random polynomial, a share distribution polynomial is calculated, a random seed is selected, and a share component polynomial is calculated; the shares are distributed to new participants, so that dynamic share distribution is realized; if a secret recovery request sent by a participant is obtained, determining a corresponding to-be-recovered participant, and sending a share component polynomial in the share of the to-be-recovered participant to other participants except the to-be-recovered participant, so that other participants calculate a transformation value according to the share component polynomial and solve the transformation value to obtain a secret value; the dynamic secret recovery is realized, the problem that a threshold scheme based on the Chinese remainder theorem cannot meet the joining of dynamic participants and the dynamic increase of a threshold value is solved, and dynamic share distribution and secret recovery are realized.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to a dynamic share distribution and secret recovery method, device, equipment and medium. Background Art

[0002] Secret sharing technology is an important primitive in cryptography, which can be used to split data and provide distributed protection for sensitive data. In addition, secret sharing technology can also be used for secure data splitting calculations. For example, it plays a key role in the "data available but invisible" function implemented by current privacy computing and federated learning. The commonly used secret sharing technologies are Shamir's threshold scheme and the threshold scheme based on the Chinese remainder theorem. However, among the existing related schemes, Shamir's threshold scheme must be operated on a finite field, and the threshold scheme based on the Chinese remainder theorem only considers static participants, that is, the number of participants is determined before the secret value is split, which cannot be applied to scenarios where participants dynamically join. Moreover, the threshold value is determined before the secret value is split and cannot be changed, and cannot provide security protection against the gradual strengthening of the adversary's attack capabilities.

[0003] From the above, it can be seen that how to solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the dynamic joining of participants and the dynamic increase of the threshold, and how to realize dynamic share distribution and secret recovery are problems to be solved in this field. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a dynamic share distribution and secret recovery method, device, equipment and medium, which can solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the dynamic participation of participants and the dynamic increase of thresholds, and realize dynamic share distribution and secret recovery. The specific scheme is as follows:

[0005] In a first aspect, the present application discloses a dynamic share distribution and secret recovery method, comprising:

[0006] Detect whether there are new participants dynamically participating in secret sharing locally, and detect whether the secret recovery request sent by the local participants is obtained;

[0007] If there is a new participant who dynamically participates in secret sharing locally, a specific degree polynomial and a random polynomial are selected by using the local share distributor, a distribution share polynomial is calculated based on the random polynomial, a random seed is selected, a share component polynomial is calculated by using the random seed, the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial are combined to generate a share, and the share is distributed to the new participant to achieve dynamic share distribution;

[0008] If a secret recovery request sent by a local participant is obtained, the corresponding participant to be recovered is determined from the local participants based on the secret recovery request, and the share component polynomial in the share of the participant to be recovered is sent to other participants except the participant to be recovered, so that the other participants can calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to realize dynamic secret recovery.

[0009] Optionally, a specific degree polynomial is selected using the local share distributor, including:

[0010] The specific degree polynomial is selected according to the preset specific degree polynomial selection requirement and the specific degree polynomial is selected by using the local share distributor; the specific degree polynomial selection requirement includes the polynomial coprime requirement and the degree selection requirement.

[0011] Optionally, the calculating the allocation share polynomial based on the random polynomial includes:

[0012] The allocation share polynomial calculation formula is used and based on the random polynomial to calculate the allocation share polynomial; the allocation share polynomial calculation formula is:

[0013] ;

[0014] in, is the allocation share polynomial, For secret, , For secret message space, is a random polynomial, The number of times is A polynomial of a certain degree.

[0015] Optionally, the formula for calculating the share component polynomial is:

[0016] ;

[0017] in, is the fractional component polynomial, The random seed selected by the random number generator when distributing shares. is the allocation share polynomial, is a polynomial that is coprime to a polynomial of a certain degree.

[0018] Optionally, the formula for calculating the share is:

[0019] ;

[0020] in, For share, is the random seed, is the first component polynomial, is the n-1th component polynomial, is the allocation share polynomial, is a polynomial of a specific degree.

[0021] Optionally, the formula for calculating the transformation value is:

[0022] ;

[0023] in, is the transformation value, The random seed selected by the random number generator for secret recovery. For other participants, is the share component polynomial of other participants, are the corresponding polynomials for the other participants.

[0024] Optionally, solving all transformed values ​​to obtain a secret value includes:

[0025] Obtaining all transformed values, and constructing a system of equations based on the transformed values;

[0026] The system of equations is solved according to the Chinese remainder theorem to obtain a unique polynomial solution, and the secret value is calculated using the unique polynomial solution.

[0027] In a second aspect, the present application discloses a dynamic share distribution and secret recovery device, comprising:

[0028] A detection module is used to detect whether there is a new participant dynamically participating in secret sharing locally, and to detect whether a secret recovery request sent by a local participant is obtained;

[0029] A share distribution module, for, if there is a new participant who dynamically participates in secret sharing locally, using the local share distributor to select a specific degree polynomial and a random polynomial, calculating a distribution share polynomial based on the random polynomial, selecting a random seed, calculating a share component polynomial using the random seed, combining the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial to generate a share, and distributing the share to the new participant to achieve dynamic share distribution;

[0030] A secret recovery module is used to determine the corresponding participant to be recovered from the local participants based on the secret recovery request if a secret recovery request sent by the local participant is obtained, and send the share component polynomial in the share of the participant to be recovered to other participants except the participant to be recovered, so that the other participants can calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to realize dynamic secret recovery.

[0031] In a third aspect, the present application discloses an electronic device, comprising:

[0032] Memory, used to store computer programs;

[0033] A processor is used to execute the computer program to implement the aforementioned dynamic share distribution and secret recovery method.

[0034] In a fourth aspect, the present application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the steps of the aforementioned disclosed dynamic share distribution and secret recovery method are implemented.

[0035] It can be seen that the present application provides a dynamic share distribution and secret recovery method, including detecting whether there is a new participant dynamically participating in secret sharing locally, and detecting whether a secret recovery request sent by the local participant is obtained; if there is a new participant dynamically participating in secret sharing locally, the local share distributor is used to select a specific degree polynomial and a random polynomial, and a distribution share polynomial is calculated based on the random polynomial, and a random seed is selected, and the share component polynomial is calculated using the random seed, and the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial are combined to generate a share, and the share is distributed to the new participant to achieve dynamic share distribution; if a secret recovery request sent by a local participant is obtained, the corresponding participant to be recovered is determined from the local participants based on the secret recovery request, and the share component polynomial in the share of the participant to be recovered is sent to other participants except the participant to be recovered, so that the other participants calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to achieve dynamic secret recovery. The present application detects whether there are new participants dynamically participating in secret sharing locally, and detects whether a secret recovery request sent by a local participant is obtained. If there are new participants, the share recovery process is executed, and a specific degree polynomial and a random polynomial are selected by a share distributor to calculate the distribution share polynomial and the share component polynomial so as to combine and generate shares to realize dynamic share distribution. If a secret recovery request is obtained, the secret recovery process is executed to determine the participant to be recovered, and the share component polynomial in the share is sent to other participants except the participant to be recovered so that other participants can calculate the transformation value, thereby solving the secret value and realizing dynamic secret recovery. There is no upper limit on the number of parameters and parties, and the threshold value increases dynamically, which can cope with the security threats brought by the enhancement of the adversary's capabilities, and solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the requirements of dynamic participant joining and the dynamic increase of the threshold value. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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.

[0037] Figure 1 A flow chart of a dynamic share distribution and secret recovery method disclosed in this application;

[0038] Figure 2A schematic diagram of the structure of a dynamic share distribution and secret recovery device disclosed in this application;

[0039] Figure 3 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0040] 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.

[0041] Secret sharing technology is an important primitive in cryptography, which can be used to split data and provide distributed protection for sensitive data. In addition, secret sharing technology can also be used for secure data splitting calculations. For example, it plays a key role in the "data available but invisible" function implemented by current privacy computing and federated learning. The commonly used secret sharing technologies are Shamir's threshold scheme and the threshold scheme based on the Chinese remainder theorem. However, among the existing related schemes, Shamir's threshold scheme must be operated on a finite field, and the threshold scheme based on the Chinese remainder theorem only considers static participants, that is, the number of participants is determined before the secret value is split, which cannot be applied to the scenario where participants dynamically join. Moreover, the threshold value is determined before the secret value is split and cannot be changed, and it cannot provide security protection against the gradual strengthening of the adversary's attack capabilities. As can be seen from the above, how to solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the problem of dynamic participation and dynamic increase of the threshold value, and how to achieve dynamic share distribution and secret recovery are problems to be solved in this field.

[0042] See also Figure 1 As shown, the embodiment of the present invention discloses a dynamic share distribution and secret recovery method, which may specifically include:

[0043] Step S11: Detect whether there is a new participant who dynamically participates in secret sharing locally, and detect whether a secret recovery request sent by the local participant is obtained.

[0044] Step S12: If there is a new participant who dynamically participates in secret sharing locally, a specific degree polynomial and a random polynomial are selected using the local share distributor, a share distribution polynomial is calculated based on the random polynomial, and a random seed is selected, and the share component polynomial is calculated using the random seed, and the share component polynomial, the random seed, the specific degree polynomial and the share distribution polynomial are combined to generate a share, and the share is distributed to the new participant to achieve dynamic share distribution.

[0045] In this embodiment, if there is a new participant who dynamically participates in secret sharing locally, the specific degree polynomial selection requirement is selected according to the preset specific degree polynomial, and the specific degree polynomial and the random polynomial are selected by using the local share distributor; the specific degree polynomial selection requirement includes the polynomial coprime requirement and the degree selection requirement; then, the distribution share polynomial is calculated based on the random polynomial using the distribution share polynomial calculation formula; the distribution share polynomial calculation formula is:

[0046] ;

[0047] in, is the allocation share polynomial, For secret, , For secret message space, is a random polynomial, The number of times is A polynomial of a certain degree;

[0048] Then, a random seed is selected and the share component polynomial is calculated using the random seed; the formula for calculating the share component polynomial is:

[0049] ;

[0050] in, is the fractional component polynomial, The random seed selected by the random number generator when distributing shares. is the allocation share polynomial, is a polynomial that is coprime to a polynomial of a certain degree.

[0051] Then, the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial are combined to generate shares, and the shares are distributed to the new participants to achieve dynamic share distribution; the formula for calculating the shares is:

[0052] ;

[0053] in, For share, is the random seed, is the first component polynomial, is the n-1th component polynomial, is the allocation share polynomial, is a polynomial of a specific degree.

[0054] Specifically, For a random number generator, for a seed ,Will The output of is grouped, and the bit string of each group is converted into a finite field The elements in , where p is a prime number; for example represents the i-th group. Representing a finite field The set of all polynomials above. In the evolutionary secret sharing mechanism, the total number of participants is variable when distributing shares. When a new participant joins, the share distributor Dealer needs to distribute the corresponding shares to the new participant. In the threshold dynamic evolutionary secret sharing structure, when the nth participant joins, the threshold required to recover the secret is , and meet . Assume that the secret message space is , is a positive integer; the secret is .make The number of times is A polynomial, where x is a variable. The threshold evolutionary secret sharing mechanism based on CRT (Chinese Remainder Theorem) mainly includes a share distribution algorithm and a secret recovery algorithm.

[0055] For the share distribution algorithm, when a new participant joins (there are new participants who dynamically participate in secret sharing locally), the Dealer performs the following steps:

[0056] First, the Dealer selects a polynomial of a specific degree and requires that the polynomial be coprime with the polynomial selected by the previous participant when joining, and has specific requirements for the degree. That is, the Dealer selects a polynomial of a specific degree. Random polynomial of ,satisfy: and , Two are mutually prime; ,and ;

[0057] Then, the dealer randomly selects a polynomial from the specific polynomial set and calculates the polynomial for allocating shares to the nth participant based on the polynomial. ,in, Indicates that all times are less than or equal to of The set of polynomials in , is from A polynomial randomly selected from ; compute the polynomial used to allocate shares to the nth participant ;

[0058] Finally, the dealer selects a random seed, calculates the share component polynomial based on the seed, and combines it into shares to distribute to the nth participant. , calculate the share component polynomial ,make Will Distributed to the nth participant as shares.

[0059] Step S13: If a secret recovery request sent by a local participant is obtained, the corresponding participant to be recovered is determined from the local participants based on the secret recovery request, and the share component polynomial in the share of the participant to be recovered is sent to other participants except the participant to be recovered, so that the other participants can calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to realize dynamic secret recovery.

[0060] In this embodiment, the share component polynomial in the share of the participant to be restored is sent to other participants except the participant to be restored, so that the other participants calculate the transformation value according to the share component polynomial. The formula for calculating the transformation value is:

[0061] ;

[0062] in, is the transformation value, The random seed selected by the random number generator for secret recovery. For other participants, is the share component polynomial of other participants, is the corresponding polynomial of other participants;

[0063] Then, all transformation values ​​are obtained, and a system of equations is constructed based on the transformation values. The system of equations is solved according to the Chinese remainder theorem to obtain a unique polynomial solution, the secret value is calculated using the unique polynomial solution, and the secret value is used to achieve dynamic secret recovery.

[0064] Specifically, after the share distribution is completed, assuming that a group of participants want to recover the secret, without loss of generality, assuming that the nth participant participates in the recovery of the secret, at this time, the other participants except the participant to be recovered constitute a minimal authorization set, which is ,The main steps of secret recovery are as follows:

[0065] First, the nth participant sends the share component polynomial in its share to the corresponding participant, and the participant calculates the transformed value of its share component polynomial based on it. , the nth participant will Send to participants ,in, Is the subscript The share component polynomial of the participants calculate ;in, Indicates that the subscript is Participants The corresponding polynomial;

[0066] Then, all participants in the minimal authorization set use the share component polynomial and the corresponding transformation value to solve the unique solution of the Chinese remainder theorem and calculate the secret value. The following system of equations can be constructed:

[0067] ;

[0068] According to the Chinese remainder theorem, the set of participants in the minimal authorization set can be solved with a number less than The only polynomial solution to , and then the secret can be calculated .

[0069] This application is based on the Chinese remainder theorem. On the basis of the existing relevant threshold secret sharing schemes, a dynamic evolution method is designed to solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the problem of dynamic participant joining and the problem of dynamic increase of threshold threshold. Based on the construction of the Chinese remainder theorem, permission control can be implemented on a general polynomial ring. In addition, there is no upper limit on the number of participants in this application, and unlimited participants can be allowed to join. The threshold value increases dynamically, which can cope with security threats brought by the enhanced capabilities of the adversary.

[0070] In this embodiment, it is detected whether there is a new participant dynamically participating in secret sharing locally, and it is detected whether a secret recovery request sent by the local participant is obtained; if there is a new participant dynamically participating in secret sharing locally, a specific degree polynomial and a random polynomial are selected by the local share distributor, and a distribution share polynomial is calculated based on the random polynomial, and a random seed is selected, and a share component polynomial is calculated using the random seed, and the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial are combined to generate a share, and the share is distributed to the new participant to achieve dynamic share distribution; if a secret recovery request sent by a local participant is obtained, the corresponding participant to be recovered is determined from the local participants based on the secret recovery request, and the share component polynomial in the share of the participant to be recovered is sent to other participants except the participant to be recovered, so that the other participants calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to achieve dynamic secret recovery. The present application detects whether there are new participants dynamically participating in secret sharing locally, and detects whether a secret recovery request sent by a local participant is obtained. If there are new participants, the share recovery process is executed, and a specific degree polynomial and a random polynomial are selected by a share distributor to calculate the distribution share polynomial and the share component polynomial so as to combine and generate shares to realize dynamic share distribution. If a secret recovery request is obtained, the secret recovery process is executed to determine the participant to be recovered, and the share component polynomial in the share is sent to other participants except the participant to be recovered so that other participants can calculate the transformation value, thereby solving the secret value and realizing dynamic secret recovery. There is no upper limit on the number of parameters and parties, and the threshold value increases dynamically, which can cope with the security threats brought by the enhancement of the adversary's capabilities, and solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the requirements of dynamic participant joining and the dynamic increase of the threshold value.

[0071] See also Figure 2 As shown, the embodiment of the present invention discloses a dynamic share distribution and secret recovery device, which may specifically include:

[0072] A detection module 11 is used to detect whether there is a new participant dynamically participating in secret sharing locally, and to detect whether a secret recovery request sent by a local participant is obtained;

[0073] The share distribution module 12 is used for, if there is a new participant who dynamically participates in secret sharing locally, selecting a specific degree polynomial and a random polynomial by using the local share distributor, calculating a distribution share polynomial based on the random polynomial, selecting a random seed, calculating a share component polynomial by using the random seed, combining the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial to generate a share, and distributing the share to the new participant to achieve dynamic share distribution;

[0074] The secret recovery module 13 is used to determine the corresponding participant to be recovered from the local participants based on the secret recovery request if a secret recovery request sent by the local participant is obtained, and send the share component polynomial in the share of the participant to be recovered to other participants except the participant to be recovered, so that the other participants can calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to realize dynamic secret recovery.

[0075] In this embodiment, it is detected whether there is a new participant dynamically participating in secret sharing locally, and it is detected whether a secret recovery request sent by the local participant is obtained; if there is a new participant dynamically participating in secret sharing locally, a specific degree polynomial and a random polynomial are selected by the local share distributor, and a distribution share polynomial is calculated based on the random polynomial, and a random seed is selected, and a share component polynomial is calculated using the random seed, and the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial are combined to generate a share, and the share is distributed to the new participant to achieve dynamic share distribution; if a secret recovery request sent by a local participant is obtained, the corresponding participant to be recovered is determined from the local participants based on the secret recovery request, and the share component polynomial in the share of the participant to be recovered is sent to other participants except the participant to be recovered, so that the other participants calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to achieve dynamic secret recovery. The present application detects whether there are new participants dynamically participating in secret sharing locally, and detects whether a secret recovery request sent by a local participant is obtained. If there are new participants, the share recovery process is executed, and a specific degree polynomial and a random polynomial are selected by a share distributor to calculate the distribution share polynomial and the share component polynomial so as to combine and generate shares to realize dynamic share distribution. If a secret recovery request is obtained, the secret recovery process is executed to determine the participant to be recovered, and the share component polynomial in the share is sent to other participants except the participant to be recovered so that other participants can calculate the transformation value, thereby solving the secret value and realizing dynamic secret recovery. There is no upper limit on the number of parameters and parties, and the threshold value increases dynamically, which can cope with the security threats brought by the enhancement of the adversary's capabilities, and solve the problem that the threshold scheme based on the Chinese remainder theorem cannot meet the requirements of dynamic participant joining and the dynamic increase of the threshold value.

[0076] In some specific embodiments, the share distribution module 12 may specifically include:

[0077] The specific degree polynomial selection module is used to select a specific degree polynomial according to a preset specific degree polynomial selection requirement and utilize a local share distributor; the specific degree polynomial selection requirement includes a polynomial coprime requirement and a degree selection requirement.

[0078] In some specific embodiments, the share distribution module 12 may specifically include:

[0079] The allocation share polynomial calculation module is used to calculate the allocation share polynomial based on the random polynomial using the allocation share polynomial calculation formula; the allocation share polynomial calculation formula is:

[0080] ;

[0081] in, is the allocation share polynomial, For secret, , For secret message space, is a random polynomial, The number of times is A polynomial of a certain degree.

[0082] In some specific embodiments, the formula for calculating the share component polynomial is:

[0083] ;

[0084] in, is the fractional component polynomial, The random seed selected by the random number generator when distributing shares. is the allocation share polynomial, is a polynomial that is coprime to a polynomial of a certain degree.

[0085] In some specific embodiments, the formula for calculating the share is:

[0086] ;

[0087] in, For share, is the random seed, is the first component polynomial, is the n-1th component polynomial, is the allocation share polynomial, is a polynomial of a specific degree.

[0088] In some specific embodiments, the formula for calculating the transformation value is:

[0089] ;

[0090] in, is the transformation value, The random seed selected by the random number generator for secret recovery. For other participants, is the share component polynomial of other participants, are the corresponding polynomials for the other participants.

[0091] In some specific embodiments, the secret recovery module 13 may specifically include:

[0092] A transformation value acquisition module, used to acquire all transformation values ​​and construct an equation group based on the transformation values;

[0093] The secret value calculation module is used to solve the equation group according to the Chinese remainder theorem to obtain a unique polynomial solution, and calculate the secret value using the unique polynomial solution.

[0094] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the dynamic share distribution and secret recovery method performed by the electronic device disclosed in any of the aforementioned embodiments.

[0095] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0096] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon include an operating system 221, a computer program 222 and data 223, etc. The storage method can be temporary storage or permanent storage.

[0097] Among them, the operating system 221 is used to manage and control the hardware devices and computer programs 222 on the electronic device 20 to realize the operation and processing of the data 223 in the memory 22 by the processor 21, which can be Windows, Unix, Linux, etc. In addition to including computer programs that can be used to complete the dynamic share distribution and secret recovery method performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can also further include computer programs that can be used to complete other specific tasks. In addition to including data transmitted from external devices received by the dynamic share distribution and secret recovery device, the data 223 can also include data collected by its own input and output interface 25, etc.

[0098] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0099] Furthermore, an embodiment of the present application also discloses a computer-readable storage medium, in which a computer program is stored. When the computer program is loaded and executed by a processor, the dynamic share distribution and secret recovery method steps disclosed in any of the aforementioned embodiments are implemented.

[0100] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0101] The above is a detailed introduction to a dynamic share distribution and secret recovery method, device, equipment and storage medium provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A dynamic share distribution and secret recovery method, characterized in that: include: Detect whether there are new participants dynamically participating in secret sharing locally, and detect whether the secret recovery request sent by the local participants is obtained; If there is a new participant who dynamically participates in secret sharing locally, a specific degree polynomial and a random polynomial are selected by using the local share distributor, a distribution share polynomial is calculated based on the random polynomial, a random seed is selected, a share component polynomial is calculated by using the random seed, the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial are combined to generate a share, and the share is distributed to the new participant to achieve dynamic share distribution; If a secret recovery request sent by a local participant is obtained, the corresponding participant to be recovered is determined from the local participants based on the secret recovery request, and the share component polynomial in the share of the participant to be recovered is sent to other participants except the participant to be recovered, so that the other participants can calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to realize dynamic secret recovery.

2. The dynamic share distribution and secret recovery method according to claim 1, characterized in that: Use the local share distributor to select a specific degree polynomial, including: The specific degree polynomial is selected according to the preset specific degree polynomial selection requirement and the specific degree polynomial is selected by using the local share distributor; the specific degree polynomial selection requirement includes the polynomial coprime requirement and the degree selection requirement.

3. The dynamic share distribution and secret recovery method according to claim 1, characterized in that: The calculating of the allocation share polynomial based on the random polynomial comprises: The allocation share polynomial calculation formula is used and based on the random polynomial to calculate the allocation share polynomial; the allocation share polynomial calculation formula is: ； in, is the allocation share polynomial, For secret, , For secret message space, is a random polynomial, The number of times is A polynomial of a certain degree.

4. The dynamic share distribution and secret recovery method according to claim 1, characterized in that: The formula for calculating the share component polynomial is: ； in, is the fractional component polynomial, The random seed selected by the random number generator when distributing shares. is the allocation share polynomial, is a coprime polynomial of a certain degree.

5. The dynamic share distribution and secret recovery method according to claim 1, characterized in that: The formula for calculating the share is: ； in, For share, is the random seed, is the first component polynomial, is the n-1th component polynomial, is the allocation share polynomial, is a polynomial of a specific degree.

6. The dynamic share distribution and secret recovery method according to claim 1, characterized in that: The formula for calculating the transformation value is: ； in, is the transformation value, The random seed selected by the random number generator for secret recovery. For other participants, is the share component polynomial of other participants, are the corresponding polynomials for the other participants.

7. The dynamic share distribution and secret recovery method according to any one of claims 1 to 6, characterized in that: The step of solving all the transformed values ​​to obtain the secret value includes: Obtaining all transformed values, and constructing a system of equations based on the transformed values; The system of equations is solved according to the Chinese remainder theorem to obtain a unique polynomial solution, and the secret value is calculated using the unique polynomial solution.

8. A dynamic share distribution and secret recovery device, characterized in that: include: A detection module is used to detect whether there is a new participant dynamically participating in secret sharing locally, and to detect whether a secret recovery request sent by a local participant is obtained; A share distribution module, for, if there is a new participant who dynamically participates in secret sharing locally, using the local share distributor to select a specific degree polynomial and a random polynomial, calculating a distribution share polynomial based on the random polynomial, selecting a random seed, calculating a share component polynomial using the random seed, combining the share component polynomial, the random seed, the specific degree polynomial and the distribution share polynomial to generate a share, and distributing the share to the new participant to achieve dynamic share distribution; A secret recovery module is used to determine the corresponding participant to be recovered from the local participants based on the secret recovery request if a secret recovery request sent by the local participant is obtained, and send the share component polynomial in the share of the participant to be recovered to other participants except the participant to be recovered, so that the other participants can calculate the transformation value according to the share component polynomial, solve all the transformation values ​​to obtain the secret value, and use the secret value to realize dynamic secret recovery.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the dynamic share distribution and secret recovery method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store a computer program; wherein, when the computer program is executed by a processor, the dynamic share distribution and secret recovery method as described in any one of claims 1 to 7 is implemented.

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