A method and system for protecting data of the entire life cycle of a smart grid

Abstract

The present invention proposes a method and system for protecting the data of the entire life cycle of a smart grid. The method includes obtaining the data of the entire life cycle during the operation of the power grid, encrypting the power parameters based on a fully homomorphic encryption algorithm during the generation stage of the power parameters; and performing operations on the power parameters in the encrypted state; the encryption process includes: determining the public key and private key of the fully homomorphic encryption algorithm; and calculating a large number of power parameters based on the public key according to the Chinese remainder theorem to obtain a first intermediate plaintext; then randomly selecting a number of bit integers from the first intermediate plaintext to calculate a ciphertext. The method also includes decrypting the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use stage. Based on this method, a protection system for the data of the entire life cycle of a smart grid is also proposed. The present invention realizes data confidentiality throughout the entire life cycle and provides a data confidentiality support for the safe operation of the smart grid.

Description

Technical Field

[0001] The present invention belongs to the technical field of power grid data protection, and in particular relates to a method and system for protecting data over the entire life cycle of a smart grid. Background Art

[0002] As the requirements for equipment safety management and refined management become higher and higher, the demand for real-time monitoring of various operating conditions becomes more urgent; how to comprehensively improve the security of data communications and provide safe and authentic data for company decision-making has become a technical problem that urgently needs to be solved in the current power distribution field.

[0003] The existing technologies are mainly divided into four types. First, the lightweight elastic protocol for secure communication. However, the premise for the normal operation of this protocol is that the initialization key is always safe and effective. Once it is leaked, it will directly affect the secure transmission of data. Second, the data encryption technology solution for cloud-based collaborative computing, which respectively calculates and stores the data encryption process and key information in the cloud and terminal, does not fully consider the storage space and computing power of the communication terminal in the smart grid. Third, the dynamic symmetric key algorithm, the network status has a greater impact on the algorithm, and the dynamic key stores the entire data group, which has a huge storage space. Fourth, data aggregation technology, after encrypting user data, it aggregates. Although it is more efficient than the traditional aggregation method, the aggregation step increases the corresponding cost and equipment burden. Therefore, although the existing technology can encrypt the power parameters, the data needs to be decrypted during processing, there is a risk of data leakage, which reduces the privacy of the data. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a method and system for protecting data of the entire life cycle of a smart grid. Data encryption is performed at the generation stage of power reference data, and the duration of the ciphertext extends to the data destruction stage, thereby achieving data confidentiality throughout the entire life cycle.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for protecting data of a smart grid throughout its life cycle comprises the following steps:

[0007] Acquire the data of the entire life cycle during the operation of the power grid, and in the generation stage of power parameters, encrypt the power parameters based on a fully homomorphic encryption algorithm; and perform operations on the power parameters in the encrypted state; the process of encrypting the power parameters with the fully homomorphic encryption algorithm includes: determining the public key and private key of the fully homomorphic encryption algorithm; and calculating a large number of power parameters based on the public key according to the Chinese remainder theorem to obtain a first intermediate plaintext; then randomly selecting a number of bit integers from the first intermediate plaintext to calculate a ciphertext.

[0008] Furthermore, the method also includes decrypting the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use phase, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; and the second intermediate plaintext is used to infer the initial plaintext based on the Chinese remainder theorem.

[0009] Furthermore, the full life cycle data during the operation of the power grid includes planning phase data, definition phase data, creation or reception phase data, processing phase data, storage phase data, integration phase data, sharing phase data, discovery phase data, use phase data, and archiving or destruction phase data.

[0010] Furthermore, the process of determining the private key of the fully homomorphic encryption algorithm includes:

[0011] Randomly select an odd number p of the first bit length e and an integer h of the second bit length t; where e=O(λ 3 );λ is the safety parameter;

[0012] Select an integer u of the third bit length e′ i , i={1,2,...h}; where u i Follows normal distribution; e'=O(λ 2 );

[0013] Using an odd number p of the first length e and an integer number u of the third length e′ i Generate private key sk = (p,u).

[0014] Furthermore, the process of determining the public key of the fully homomorphic encryption algorithm includes:

[0015] From the interval [0,2 g / p) randomly select two integers q0 and q1, and calculate x0=pq0. And x0 and x1 are relatively prime, x0 is greater than x1; where g is the bit length of x0 and x1, g = O(λ 4 );

[0016] Randomly select k prime numbers n that are mutually prime i As part of the public key, calculate The public key is pk=(x0,x1,n,(n1,n2,...,n k )).

[0017] Furthermore, the first intermediate plaintext is obtained by calculating a large number of power parameters based on the public key according to the Chinese remainder theorem; and then a number of bit integers are randomly selected from the first intermediate plaintext to calculate the ciphertext. The detailed process is:

[0018] According to the Chinese remainder theorem, for k initial plaintexts π1,π2,...,π k Calculate and get the first intermediate plaintext m∈Z n ; Assume l i =n / n i , Then there is Among them l i is the ratio parameter, v in the Chinese remainder theorem i is the product parameter in the Chinese Remainder Theorem;

[0019] An integer r of the fourth bit s is randomly selected from the first intermediate plaintext m, where The ciphertext c=(m+rx1)modx0 is calculated.

[0020] Furthermore, the decryption process includes in detail:

[0021] Given a ciphertext c and a private key sk = (p,u), run the decryption algorithm to calculate the second intermediate plaintext m = (cmodp)modu;

[0022] According to the Chinese remainder theorem, m = π i modn i ; Calculate k initial plaintexts π1,π2,...,π k , and π i =m-[m / n i ]n i .

[0023] The present invention also proposes a smart grid full life cycle data protection system, including an encryption module;

[0024] The encryption module is used to obtain full life cycle data during the operation of the power grid. In the generation stage of power parameters, the power parameters are encrypted based on a fully homomorphic encryption algorithm; and operations are performed on the power parameters in the encrypted state; the process of encrypting the power parameters using the fully homomorphic encryption algorithm includes: determining the public key and private key of the fully homomorphic encryption algorithm; and based on the public key, a large number of power parameters are calculated according to the Chinese remainder theorem to obtain a first intermediate plaintext; then a number of bit integers are randomly selected from the first intermediate plaintext to calculate a ciphertext.

[0025] Furthermore, the system also includes a decryption module;

[0026] The decryption module is used to decrypt the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use phase, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; and the second intermediate plaintext is used to infer the initial plaintext based on the Chinese remainder theorem.

[0027] Furthermore, the full life cycle data during the operation of the power grid includes planning phase data, definition phase data, creation or reception phase data, processing phase data, storage phase data, integration phase data, sharing phase data, discovery phase data, use phase data, and archiving or destruction phase data.

[0028] The effects provided in the content of the invention are only the effects of the embodiments, not all the effects of the invention. One of the above technical solutions has the following advantages or beneficial effects:

[0029] The present invention proposes a method and system for protecting the full life cycle data of a smart grid. The method includes obtaining the full life cycle data during the operation of the power grid, encrypting the power parameters based on a fully homomorphic encryption algorithm during the generation stage of the power parameters; and performing operations on the power parameters in the encrypted state; the process of encrypting the power parameters by the fully homomorphic encryption algorithm includes: determining the public key and private key of the fully homomorphic encryption algorithm; and calculating a large number of power parameters based on the public key according to the Chinese remainder theorem to obtain a first intermediate plaintext; then randomly selecting a number of bit integers from the first intermediate plaintext to calculate a ciphertext. The method also includes decrypting the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use stage, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; and the second intermediate plaintext is used to infer the initial plaintext based on the Chinese remainder theorem. Based on a method for protecting the full life cycle data of a smart grid, a protection system for the full life cycle data of a smart grid is also proposed. The present invention adopts a data asset full life cycle model, models the power parameters throughout their life cycle, and adopts a fully homomorphic encryption algorithm to encrypt data during the generation phase of power reference data. The duration of the ciphertext extends to the data destruction phase, thereby achieving data confidentiality throughout the entire life cycle and providing a data confidentiality support solution for the safe operation of the smart grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] like Figure 1 It is the full life cycle model of the power parameters in Example 1 of the present invention;

[0031] like Figure 2 This is a flow chart of a method for protecting data in the entire life cycle of a smart grid according to Embodiment 1 of the present invention;

[0032] like Figure 3 This is a schematic diagram of a protection system for data of the entire life cycle of a smart grid according to Embodiment 2 of the present invention. DETAILED DESCRIPTION

[0033] In order to clearly illustrate the technical features of the present solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings. The disclosure below provides many different embodiments or examples for realizing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and settings of specific examples are described below. In addition, the present invention may repeat reference numbers and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. It should be noted that the components illustrated in the accompanying drawings are not necessarily drawn to scale. The present invention omits the description of known components and processing techniques and processes to avoid unnecessary limitations on the present invention.

[0034] Example 1

[0035] Embodiment 1 of the present invention proposes a method for protecting data in the entire life cycle of a smart grid. The data life cycle management model defines a macroscopic framework, which is a panoramic view of the complete life cycle of data from the production stage to the destruction stage. Figure 1 This is the full life cycle model of the power parameters in Example 1 of the present invention; the data asset full life cycle divides data into 11 stages, including planning, definition, creation / reception, processing, integration, storage, operation and maintenance, sharing, discovery, use and reuse, archiving & destruction.

[0036] like Figure 2 This is a flow chart of a method for protecting data in the entire life cycle of a smart grid according to Embodiment 1 of the present invention;

[0037] In step S200, the full life cycle data of the power grid operation process is obtained, and in the generation stage of power parameters, the power parameters are encrypted based on a fully homomorphic encryption algorithm; and operations are performed on the power parameters in the encrypted state; the process of encrypting the power parameters using the fully homomorphic encryption algorithm includes: determining the public key and private key of the fully homomorphic encryption algorithm; and based on the public key, a large number of power parameters are calculated according to the Chinese remainder theorem to obtain a first intermediate plaintext; then a number of bit integers are randomly selected from the first intermediate plaintext to calculate a ciphertext.

[0038] The present invention is based on a data life cycle management model, and then based on an integer fully homomorphic encryption algorithm, encrypts data at the generation stage of power parameters, and the data exists in ciphertext form from generation to destruction. The full life protection of power parameters involved in the present invention begins at the data creation / reception stage, which is the stage of data entity generation and data encryption. The power parameters are first encoded in ASCII, and then the ASCII code is converted into decimal, represented by π and grouped, and each group has a value range of m∈Z n

[0039] The idea of ​​encryption is: for i∈{1,2,...,k}, there is an initial k plaintext π1,π2,...,π k , Using homomorphic mapping, an intermediate plaintext can be calculated Based on the Chinese remainder theorem and the mapping used The homomorphic property of the intermediate plaintext m is equivalent to the calculation of k initial plaintexts π1,π2,...,π k , thereby realizing batch processing operations on multiple integers.

[0040] The process of determining the private key of the fully homomorphic encryption algorithm includes:

[0041] Randomly select an odd number p of the first bit length e and an integer h of the second bit length t; to resist brute force attacks e=O(λ 3 );λ is the safety parameter;

[0042] The larger the value of the λ parameter, the higher the security of the scheme and the lower the computational efficiency. Considering the security of power parameter data protection and the degree of ciphertext expansion, the recommended value in practical applications is λ = 42.

[0043] The bit length of the random quantity h is introduced in the process of generating the public key x1 to support homomorphic computation of the intermediate plaintext.

[0044] Select an integer u of the third bit length e′ i , i={1,2,...h}; where u i Follows normal distribution; To support homomorphic computation of intermediate plaintext, e'=O(λ 2 );

[0045] Using an odd number p of the first length e and an integer number u of the third length e′ i Generate private key sk = (p,u).

[0046] The process of determining the public key of the fully homomorphic encryption algorithm includes:

[0047] From the interval [0,2 g / p) randomly select two integers q0 and q1, and calculate x0=pq0. And x0 and x1 are relatively prime, x0 is greater than x1; where g is the bit length of x0 and x1, to resist lattice attacks, g = O(λ 4 );

[0048] Randomly select k prime numbers n that are mutually prime i As part of the public key, calculate The public key is pk=(x0,x1,n,(n1,n2,...,n k )); k is the number of plaintext spaces, because n = 2 O(β) ,have

[0049] Based on the public key, a large number of power parameters are calculated according to the Chinese remainder theorem to obtain the first intermediate plaintext; then, a number of bit integers are randomly selected from the first intermediate plaintext, and the detailed process of calculating the ciphertext is as follows:

[0050] According to the Chinese remainder theorem, for k initial plaintexts π1,π2,...,π k Calculate and get the first intermediate plaintext m∈Z n ; Assume l i =n / n i , Then there is Among them l i is the ratio parameter, v in the Chinese remainder theorem i is the product parameter in the Chinese Remainder Theorem;

[0051] An integer r of the fourth bit s is randomly selected from the first intermediate plaintext m, where The ciphertext c=(m+rx1)modx0 is calculated.

[0052] In the encryption process, the bit length of the random quantity r is introduced to increase the security of the scheme. In order to support homomorphic calculation of the initial plaintext,

[0053] In step S210, the encrypted power parameters are decrypted based on the private key of the fully homomorphic encryption algorithm during the use phase, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; and deducing the initial plaintext from the second intermediate plaintext based on the Chinese remainder theorem.

[0054] The decryption process includes:

[0055] Given a ciphertext c and a private key sk = (p,u), run the decryption algorithm to calculate the second intermediate plaintext m = (cmodp)modu;

[0056] According to the Chinese remainder theorem, m = π i modn i ; Calculate k initial plaintexts π1,π2,...,π k , and π i =m-[m / n i ]n i .

[0057] In summary, the homomorphic encryption algorithm Eval(f,(c1,...,cl )). Given a function f with l variables, and l ciphertexts (c1, c2, ..., c l ), satisfying c i =Enc(sk,m i ), input l ciphertexts into the function to perform homomorphic operations and output ciphertext c.

[0058] Function f can be decomposed into a combination of addition and multiplication. For two ciphertexts c1 and c2, the homomorphic calculations are: add =(c1+c2)modx0; c mult =(c1·c2)modx0. After the homomorphic computation algorithm Eval(f,(c1,...,c l ))The ciphertext c obtained is decrypted by decryption algorithm Dec to obtain the corresponding plaintext.

[0059] Fully homomorphic encryption refers to an encryption function that satisfies both the additive homomorphism and the multiplicative homomorphism properties and can perform any number of addition and multiplication operations; where: C add represents the addition homomorphism, C mult Represents multiplication homomorphism.

[0060] Using homomorphic encryption technology, the result obtained by the user after operating on the ciphertext and then decrypting it is consistent with the result obtained by directly operating on the plaintext. This feature allows untrusted third parties to directly operate on the ciphertext without a private key, avoiding the leakage of user sensitive information caused by the need to decrypt the ciphertext during the operation process. Using homomorphic encryption technology, the result obtained by the user after operating on the ciphertext and then decrypting it is consistent with the result obtained by directly operating on the plaintext. This feature allows untrusted third parties to directly operate on the ciphertext without a private key, avoiding the possibility of leakage of user sensitive information caused by the need to decrypt the ciphertext during the operation process.

[0061] The correctness proof of the scheme includes: first, proving the correctness of the decryption algorithm Dec when homomorphic computation is not performed; then proving the correctness of the homomorphic computation algorithm Eval.

[0062] Given a private key sk = (p,u), for the initial ciphertext c, the decryption algorithm can correctly decrypt k initial plaintexts π1, π2, ..., π k . Proof: For k plaintexts π1,π2,...,π k , let l i =n / n i , Calculate the intermediate plaintext And m∈Z n。From the encryption algorithm, we know that c = (m_rx1) mod x0. There exists an integer l1, and the ciphertext is c = (m + rx1) - l1·x0. Given x0 = pq0 and x1 = pq1 + uh, according to the selected parameters, we have urh + m << p and m << u i holds. Calculate m = (c mod p) mod u to decrypt and obtain the correct intermediate plaintext m, and then obtain k initial plaintexts π1, π2,..., π k 。

[0063] For two ciphertexts c1 = Enc(pk, m1) and c2 = Enc(pk, m2), the homomorphic addition operation is c add = (c1 + c2) mod x0. According to the parameter settings, the bit length of the second private key u used in the scheme is O(λ 2 ), and the bit length of the random quantity r used is According to the triangle inequality, it can be known that for the ciphertext c add = (c1 + c2) mod x0 obtained by one homomorphic addition, the noise, and the noise bit length increases by at most 1 bit. Then the scheme can support O(λ 2 ) addition homomorphic calculations.

[0064] For the multiplication homomorphic operation c mult = (c1·c2) mod x0, when multiplying d ciphertexts, the corresponding noise is the (d + 1)-th power of the original noise, and the noise bit length increases by at most d + 1 times. Therefore, the main factor affecting the polynomial degree that the scheme can calculate is the homomorphic multiplication operation. In this paper, the polynomial that the scheme can support homomorphic calculation is represented by the function f, and the order of this polynomial is d = deg(f).

[0065] There exists an arithmetic circuit C, and the corresponding multivariate polynomial is f. Given ||f||1 is the 1-norm of the coefficient vector corresponding to the polynomial f, and the polynomial order is d = deg(f). When ||f||1(2 β+αs ) d ≤ 2 e-2 , the arithmetic circuit C corresponding to this polynomial ∈ C per-c is an admissible circuit.

[0066] According to the parameter settings, using the lemma, it can be obtained that the order of the polynomial that the scheme can support homomorphic calculation is For the ciphertext, it can support at most homomorphic multiplication operations. When selecting parameters, the value of log2(||f||1) can be set to be less than e and β.

[0067] The security verification of the scheme includes: using a game consisting of the adversary atk and the solver ξ to prove the security of the scheme. The game can be described as follows: first, the adversary atk obtains the public key, and then the adversary gives two different plaintexts to ζ. ζ randomly selects a plaintext to encrypt and obtain the corresponding ciphertext, and returns the ciphertext to the adversary atk. The adversary uses the public key and the obtained ciphertext to initiate a guess. If the adversary can correctly guess the plaintext selected by ζ, the adversary wins the game. If the probability that the adversary correctly guesses the plaintext is 1 / 2+negl(λ), where negl(λ) is a negligible amount, the scheme is called secure. The scheme relies on a complexity problem, namely the random approximate common factor problem (RAGCD), which is a variant of the AGCD problem. When constructing the RAGCD problem, u i It obeys uniform distribution. As h increases, according to the law of large numbers, the probability that u obeys Gaussian distribution is 1-negl(λ). Compared with AGCD problem, RAGCD problem is more complicated. The security of the scheme is reduced to RAGCD problem.

[0068] The biggest advantage of the present invention compared to the prior art is that it has a smaller key size and a smaller ciphertext expansion rate.

[0069] Complexity analysis includes: key size, encryption complexity, decryption complexity, and homomorphic computation complexity. The complexity demonstration process of the present invention includes: the fully homomorphic encryption algorithm used, the public key consists of two O(λ 4 )-bit large integer, and a set of k O(λ)-bit small prime numbers, the key size is O(λ 4 ).

[0070] The encryption algorithm consists of two stages: 1. Generate intermediate plaintext from initial plaintext. k To calculate the intermediate plaintext m, the calculation requires k divisions, 2k modular operations and multiplications, and k-1 additions. The computational complexity is 2. Perform encryption calculation on the intermediate plaintext to generate ciphertext. Encryption calculation is a process with a complexity of O(λ 5 ) multiplication calculation, generating a bit size of about O(λ 4 ) ciphertext. This is followed by a modular operation with a modulus of one bit, which is approximately O(λ 4 ) integer x0, the complexity of this modular operation is O(λ 8 ).

[0071] Decryption is performed as two modular reduction operations. The first modular reduction is about O(λ 4 ) has a ciphertext and bit size of approximately O(λ 3 ) is calculated with the private key p, the resulting computational complexity should be O(λ 8), and we get a bit size of about O(λ 3 ). This value is then modularly reduced to obtain a bit size of approximately O(λ 2 ), the computational complexity of the second modular reduction is O(λ 6 ), and we get a bit size of about O(λ 2 ) of the intermediate plaintext. k In the conversion, k rounding operations and k multiplication and subtraction operations are required, and the computational complexity is

[0072] Homomorphic computational complexity. Homomorphic addition is relatively simple, which is to directly add two ciphertexts. The algorithm complexity is O(λ 4 ); After an addition is completed, the size of the ciphertext does not increase, so the corresponding decryption algorithm complexity remains unchanged; homomorphic multiplication is to multiply two ciphertexts, obtain an integer and then reduce it modulo x0, so the complexity is O(λ 8 ). Combining the above complexity analysis, we can conclude that the overall computational complexity of the solution is O(λ 8 ).

[0073] A method for protecting data of a smart grid throughout its life cycle proposed in Example 1 of the present invention adopts a data asset life cycle model, models power parameters throughout their life cycle, and adopts a fully homomorphic encryption algorithm. Data encryption is performed during the generation phase of power reference data, and the duration of the ciphertext is extended to the data destruction phase, thereby achieving data confidentiality throughout the entire life cycle and providing a data confidentiality support solution for the safe operation of the smart grid.

[0074] Example 2

[0075] Based on the method for protecting data of the entire life cycle of a smart grid proposed in Example 1 of the present invention, Example 2 of the present invention proposes a system for protecting data of the entire life cycle of a smart grid, such as Figure 3 This is a schematic diagram of a smart grid full life cycle data protection system according to Embodiment 2 of the present invention, the system comprising: an encryption module and a decryption module;

[0076] Among them, the encryption module is used to obtain the full life cycle data during the operation of the power grid. In the generation stage of power parameters, the power parameters are encrypted based on the fully homomorphic encryption algorithm; and operations are performed on the power parameters in the encrypted state; the process of encrypting the power parameters with the fully homomorphic encryption algorithm includes: determining the public key and private key of the fully homomorphic encryption algorithm; and based on the public key, a large number of power parameters are calculated according to the Chinese remainder theorem to obtain a first intermediate plaintext; then a number of bit integers are randomly selected from the first intermediate plaintext to calculate the ciphertext.

[0077] The system also includes a decryption module; the decryption module is used to decrypt the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use phase, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; the second intermediate plaintext is used to infer the initial plaintext based on the Chinese remainder theorem.

[0078] The process of implementing the encryption module includes: randomly selecting an odd number p of the first bit length e and an integer h of the second bit length t; in order to resist the brute force attack e=O(λ 3 );λ is the safety parameter;

[0079] The larger the value of the λ parameter, the higher the security of the scheme and the lower the computational efficiency. Considering the security of power parameter data protection and the degree of ciphertext expansion, the recommended value in practical applications is λ = 42.

[0080] The bit length of the random quantity h is introduced in the process of generating the public key x1 to support homomorphic computation of the intermediate plaintext.

[0081] Select an integer u of the third bit length e′ i , i={1,2,...h}; where u i Follows normal distribution; To support homomorphic computation of intermediate plaintext, e'=O(λ 2 );

[0082] Using an odd number p of the first length e and an integer number u of the third length e′ i Generate private key sk = (p,u).

[0083] The process of determining the public key of the fully homomorphic encryption algorithm includes:

[0084] From the interval [0,2 g / p) randomly select two integers q0 and q1, and calculate x0=pq0. And x0 and x1 are relatively prime, x0 is greater than x1; where g is the bit length of x0 and x1, to resist lattice attacks, g = O(λ 4 );

[0085] Randomly select k prime numbers n that are mutually prime i As part of the public key, calculate The public key is pk=(x0,x1,n,(n1,n2,...,n k )); k is the number of plaintext spaces, because n = 2 O(β) ,have

[0086] Based on the public key, a large number of power parameters are calculated according to the Chinese remainder theorem to obtain the first intermediate plaintext; then, a number of bit integers are randomly selected from the first intermediate plaintext, and the detailed process of calculating the ciphertext is as follows:

[0087] According to the Chinese remainder theorem, for k initial plaintexts π1,π2,...,π k Calculate and get the first intermediate plaintext m∈Z n ; Assume l i =n / n i , Then there is Among them l i is the ratio parameter, v in the Chinese remainder theorem i is the product parameter in the Chinese Remainder Theorem;

[0088] An integer r of the fourth bit s is randomly selected from the first intermediate plaintext m, where The ciphertext c=(m+rx1)modx0 is calculated.

[0089] In the encryption process, the bit length of the random quantity r is introduced to increase the security of the scheme. In order to support homomorphic calculation of the initial plaintext,

[0090] The process of implementing the decryption module includes: given a ciphertext c and a private key sk = (p,u), running the decryption algorithm to calculate the second intermediate plaintext m = (cmodp) modu;

[0091] According to the Chinese remainder theorem, m = π i modn i ; Calculate k initial plaintexts π1,π2,...,π k , and π i =m-[m / n i ]n i .

[0092] A smart grid full life cycle data protection system proposed in Example 2 of the present invention adopts a data asset full life cycle model, models the power parameters throughout their life cycle, and adopts a fully homomorphic encryption algorithm. Data encryption is performed during the power reference data generation phase. The duration of the ciphertext extends to the data destruction phase, thereby achieving data confidentiality throughout the entire life cycle and providing a data confidentiality support solution for the safe operation of the smart grid.

[0093] 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 that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment that includes a series of elements are inherent to the elements. In the absence of more restrictions, the elements limited by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment that includes the elements. In addition, the above-mentioned technical solution provided in the embodiment of the present application is consistent with the corresponding technical solution in the prior art in principle, and the part is not described in detail, so as not to repeat too much.

[0094] Although the above describes the specific implementation of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. For those skilled in the art, other different forms of modifications or deformations can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. On the basis of the technical solution of the present invention, various modifications or deformations that can be made by those skilled in the art without creative work are still within the scope of protection of the present invention.

Claims

1. A method for protecting data in the entire life cycle of a smart grid, characterized in that: The following steps are involved: Acquire the full life cycle data during the operation of the power grid, and encrypt the power parameters based on the fully homomorphic encryption algorithm during the generation stage of the power parameters; and performing operations on power parameters in an encrypted state; The process of encrypting the power parameter using the fully homomorphic encryption algorithm includes: determining a public key and a private key of the fully homomorphic encryption algorithm; and calculating a large number of power parameters based on the public key according to the Chinese remainder theorem to obtain a first intermediate plaintext; and then randomly selecting a plurality of bit integers from the first intermediate plaintext to calculate a ciphertext; The process of determining the private key of the fully homomorphic encryption algorithm includes: Randomly select an odd number p of the first bit length e and an integer h of the second bit length t; where e=O(λ 3 );λ is the safety parameter; Select an integer u of the third bit length e′ i , i={1,2,...h}; where u i Follows normal distribution; e'=O(λ 2 ); Using an odd number p of the first length e and an integer number u of the third length e′ i Generate private key sk = (p,u); The process of determining the public key of the fully homomorphic encryption algorithm includes: Randomly select two integers q0 and q1 from the interval [0,2g / p) and calculate x0=pq0, And x0 and x1 are relatively prime, x0 is greater than x1; where g is the bit length of x0 and x1, g = O(λ 4 ); Randomly select k prime numbers n that are mutually prime i As part of the public key, calculate The public key is pk=(x0,x1,n,(n1,n2,...,n k )); The first intermediate plaintext is obtained by calculating a large number of power parameters based on the public key according to the Chinese remainder theorem; then a number of bit integers are randomly selected from the first intermediate plaintext to calculate the ciphertext. The detailed process is as follows: According to the Chinese remainder theorem, for k initial plaintexts π1,π2,...,π k Calculate and get the first intermediate plaintext m∈Z n ; Assume l i =n / n i , Then there is Among them l i is the ratio parameter, v in the Chinese remainder theorem i is the product parameter in the Chinese Remainder Theorem; An integer r of the fourth bit s is randomly selected from the first intermediate plaintext m, where The ciphertext c=(m+rx1)modx0 is calculated.

2. A method for protecting data of the entire life cycle of a smart grid according to claim 1, characterized in that: The method also includes decrypting the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use phase, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; and deducing the initial plaintext from the second intermediate plaintext based on the Chinese remainder theorem.

3. A method for protecting data of a smart grid throughout its life cycle according to claim 2, characterized in that: The full life cycle data during the power grid operation process includes planning phase data, definition phase data, creation or reception phase data, processing phase data, storage phase data, integration phase data, sharing phase data, discovery phase data, use phase data and archiving or destruction phase data.

4. A method for protecting data of a smart grid throughout its life cycle according to claim 2, characterized in that: The decryption process includes in detail: Given a ciphertext c and a private key sk = (p,u), run the decryption algorithm to calculate the second intermediate plaintext m = (cmodp)modu; According to the Chinese remainder theorem, m = π i modn i ; Calculate k initial plaintexts π1,π2,...,π k , and π i =m-[m / n i ]n i .

5. A smart grid full life cycle data protection system, used to execute a smart grid full life cycle data protection method according to any one of claims 1 to 4, characterized in that: Includes encryption module; The encryption module is used to obtain the full life cycle data during the operation of the power grid, and encrypt the power parameters based on the fully homomorphic encryption algorithm during the generation stage of the power parameters; and performing operations on power parameters in an encrypted state; The process of encrypting the power parameters using the fully homomorphic encryption algorithm includes: determining the public key and private key of the fully homomorphic encryption algorithm; and calculating a large number of power parameters based on the public key according to the Chinese remainder theorem to obtain a first intermediate plaintext; and then randomly selecting a number of bit integers from the first intermediate plaintext to calculate a ciphertext.

6. A smart grid full life cycle data protection system according to claim 5, characterized in that: The system also includes a decryption module; The decryption module is used to decrypt the encrypted power parameters based on the private key of the fully homomorphic encryption algorithm during the use phase, wherein the decryption process includes calculating a second intermediate plaintext based on the ciphertext and the private key; and the second intermediate plaintext is used to infer the initial plaintext based on the Chinese remainder theorem.

7. A smart grid full life cycle data protection system according to claim 6, characterized in that: The full life cycle data during the power grid operation process includes planning phase data, definition phase data, creation or reception phase data, processing phase data, storage phase data, integration phase data, sharing phase data, discovery phase data, use phase data and archiving or destruction phase data.

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