A dynamic cross-chaotic encryption method and system applied to smart grid

Abstract

The present invention provides a dynamic cross-chaotic encryption method and system applied to a smart grid. The method of the present invention includes obtaining an encrypted signal and an encryption time transmitted by the smart grid; determining an encryption key stream by using a dynamic cross-chaotic mapping equation, which is based on the Logistic mapping equation and introduces a dynamic cross operator for generating an encryption key stream considering the influence of the encryption time and adjacent key values; and performing an exclusive OR operation on the encryption key stream and the encrypted signal to obtain an encrypted signal. The present invention realizes data encryption by adopting chaotic encryption technology, meets the security requirements of the smart grid for data transmission. At the same time, by introducing a dynamic cross operator, the present invention effectively amplifies errors, making attacks on initial conditions ineffective, thereby greatly improving the brute force attack threshold.

Description

Technical Field

[0001] The present invention belongs to the technical field of smart grid communication, and specifically relates to a dynamic cross-chaotic encryption method and system applied to a smart grid. Background Art

[0002] With the in-depth application of information technology in the power field, the smart grid deeply integrates traditional power grids and technologies such as cloud computing and artificial intelligence. The intelligent control center can collect and analyze various information of a large number of users and make decisions to increase revenue.

[0003] The smart grid is the intelligentization of the traditional power grid. The smart grid realizes two-way information interaction through advanced sensing and measurement technologies, advanced equipment technologies, advanced control methods, and advanced decision support system technologies. However, with the increase in the openness of the smart grid, various information and privacy of users are facing security risks. The smart grid has characteristics such as complexity, strong coupling, and strong correlation. Under this background, it is of great practical significance to study user data security and privacy protection. Therefore, encryption technology in the data transmission process plays a crucial role in the development of the smart grid.

[0004] The data transmission of the existing power grid usually adopts internationally common encryption algorithms, which cannot meet the security requirements of the smart grid for massive data transmission. Summary of the Invention

[0005] In view of this, the present invention aims to solve the problem that the data transmission of the existing power grid usually adopts internationally common encryption algorithms, which cannot meet the security requirements of the smart grid for massive data transmission.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a dynamic cross-chaotic encryption method applied to a smart grid. Based on the Logistic mapping equation, considering the influence of the encryption time and adjacent values, a dynamic cross-chaotic mapping equation is generated, including the following steps:

[0008] Obtain the signal to be encrypted transmitted by the smart grid and the encryption time. The signal to be encrypted is a binary plaintext data stream;

[0009] Generate an encryption key stream using the dynamic cross-chaotic mapping equation. The encryption key stream does not include the initial value;

[0010] Perform an exclusive OR operation on the encryption key stream and the signal to be encrypted to obtain an encrypted signal.

[0011] Further, the dynamic cross-chaotic mapping equation is specifically determined by the following calculation formula:

[0012]

[0013] In the formula, ψ(t) is the dynamic crossover operator, and T sec is the encryption time, x n and x n+1 are two adjacent values in the random sequence, n is a natural number, and μ is the control parameter variable.

[0014] Furthermore, the dynamic crossover operator is specifically determined by the following calculation formula:

[0015]

[0016] In the formula, is the crossover coefficient.

[0017] Furthermore, the encrypted key stream is determined by using the dynamic crossover chaotic mapping equation, specifically including:

[0018] Initialize the control parameter variable μ and the initial value x0;

[0019] Generate a set of random sequences by using the dynamic crossover chaotic mapping equation, and the initial value x0 is not included in the random sequence;

[0020] For each value in the random sequence, take M significant digits to form an integer Y, and take the remainder of the integer Y divided by 256 to obtain a one-byte key;

[0021] The one-byte keys corresponding to each value in the random sequence form the encrypted key stream.

[0022] In the second aspect, the present invention provides a dynamic crossover chaotic encryption system applied to a smart grid. Based on the Logistic mapping equation, considering the influence of the encryption time and adjacent values, a dynamic crossover chaotic mapping equation is generated, including:

[0023] A signal acquisition unit for acquiring the signal to be encrypted and the encryption time transmitted by the smart grid;

[0024] A key generation unit for generating an encrypted key stream by using the dynamic crossover chaotic mapping equation, and the initial value is not included in the encrypted key stream;

[0025] An encryption operation unit for performing an exclusive OR operation on the encrypted key stream and the signal to be encrypted to obtain an encrypted signal.

[0026] Furthermore, the dynamic crossover chaotic mapping equation is specifically determined by the following calculation formula:

[0027]

[0028] In the formula, ψ(t) is the dynamic crossover operator, and T sec is the encryption time, x nand x n+1 are two adjacent values in the random sequence, and μ is a control parameter variable.

[0029] Furthermore, the dynamic crossover operator is specifically determined by the following calculation formula:

[0030]

[0031] In the formula, is the crossover coefficient.

[0032] Furthermore, the secret key generation unit determines the encrypted secret key stream by using the dynamic crossover chaotic mapping equation, specifically including:

[0033] Initialize the control parameter variable μ and the initial value x0;

[0034] Generate a set of random sequences by using the dynamic crossover chaotic mapping equation, and the random sequence does not include the initial value x0;

[0035] For each value in the random sequence, take M significant digits to form an integer Y, and take the remainder of the integer Y divided by 256 to obtain a one-byte secret key;

[0036] The one-byte secret keys corresponding to each value in the random sequence form the encrypted secret key stream.

[0037] In summary, the present invention provides a dynamic crossover chaotic encryption method and system applied to an intelligent power grid. The method of the present invention includes obtaining a signal to be encrypted transmitted by the intelligent power grid and an encryption time; determining an encrypted secret key stream by using the dynamic crossover chaotic mapping equation. The dynamic crossover chaotic mapping equation introduces a dynamic crossover operator on the basis of the Logistic mapping equation to generate an encrypted secret key stream considering the influence of the encryption time and adjacent secret key values; performing an exclusive OR operation on the encrypted secret key stream and the signal to be encrypted to obtain an encrypted signal. The present invention realizes data encryption by adopting chaotic encryption technology, meets the security requirements of the intelligent power grid for data transmission. At the same time, the present invention effectively amplifies errors by introducing a dynamic crossover operator, making attacks on initial conditions ineffective, thereby greatly increasing the brute force attack threshold. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0039] Figure 1 is a schematic flowchart of a dynamic crossover chaotic encryption method applied to an intelligent power grid provided by an embodiment of the present invention;

[0040] Figure 2 It is a schematic flowchart of the dynamic cross-chaos encryption provided by the embodiments of the present invention. Detailed implementation manners

[0041] To make the objectives, features, and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the embodiments described below are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0042] With the in-depth application of information technology in the power field, the smart grid deeply integrates traditional power grids and technologies such as cloud computing and artificial intelligence. The intelligent control center can collect and analyze various information of a large number of users and make decisions to increase revenue.

[0043] The smart grid is the intelligentization of the traditional power grid. The smart grid realizes two-way information interaction through advanced sensing and measurement technologies, advanced equipment technologies, advanced control methods, and advanced decision support system technologies. However, with the increase in the openness of the smart grid, various information and privacy of users are facing security risks. The smart grid has characteristics such as complexity, strong coupling, and strong correlation. Under this background, it is of great practical significance to study the data security and privacy protection of users. Therefore, the encryption technology in the data transmission process plays a crucial role in the development of the smart grid.

[0044] The data transmission of the existing power grid usually adopts internationally common encryption algorithms and cannot meet the security requirements of the smart grid for massive data transmission. The chaos encryption technology is an important branch of nonlinear science that has developed rapidly in recent years and is particularly suitable for fields such as digital communication and multimedia data security. The present invention realizes the data transmission encryption of the smart grid based on the chaos encryption technology. The following makes a simple introduction to the chaos encryption technology.

[0045] Chaos is a seemingly irregular motion, which means that in a deterministic nonlinear system, random behavior can occur without adding any random factors, that is, inherent randomness. It belongs to a deterministic system but is difficult to predict, is implicit in a complex system but is inseparable, and presents a variety of chaotic but quite regular dynamic processes. Its biggest feature is that the system is extremely sensitive to the initial conditions.

[0046] The application of chaos in cryptography is mainly based on the basic characteristics of chaos, such as ergodicity, mixing property, determinism, and sensitivity to initial conditions. The chaotic sequences generated by chaotic systems possess complexity, randomness, difficulty in analysis and prediction, which make them potentially a practical cryptographic system [1] 。

[0047] The Logistic map represents a non-linear chaotic equation, and its mapping process is shown as follows

[0048] x n+1 =μx n (1 - x n ) (1)

[0049] In the formula, μ represents the control parameter variable. After determining the specific value of μ, through a random initial value x0 ∈ [0, 1], a definite time series x0, x1, x2... x can be iteratively calculated n 。

[0050] The form of equation (1) is completely determined and does not contain any random factors. However, due to its non-linear characteristics, it can generate a series of seemingly completely random chaotic solutions x(n) that are extremely sensitive to the initial condition x(0). A slight change in x(0) can generate completely different chaotic series.

[0051] The security of chaotic sequence encryption mainly depends on the chaotic key stream. In a chaotic encryption system, the random sequence {x i} generated by the chaotic system is used as the key stream {k i} and the plaintext data stream {m i} for bitwise operation, and then the ciphertext data stream {c i} is obtained. The plaintext data stream is binary, and the key stream {k i} is obtained by performing data processing on the chaotic sequence {x i}.

[0052] However, the above chaotic encryption system belongs to a one-dimensional discrete-time non-linear dynamic system, which is easy to implement but has problems such as weak confidentiality and possible degradation of the characteristics of the digital chaotic system under limited precision; at the same time, the current chaotic encryption systems usually adopt multiple iteration methods, which can improve the encryption effect to a certain extent, but also greatly increase the computational cost of the encryption process and are not suitable for use in systems with high requirements for data transmission real-time performance. Moreover, the method of multiple iterations cannot essentially change the random sequence generation method. In the case of the Logistic map being confirmed, even with multiple iteration encryption, it is still relatively easy for attackers to further crack by brute force.

[0053] Based on this, the present invention provides a dynamic cross-chaotic encryption method and system applied to smart grids.

[0054] The following is a detailed introduction to an embodiment of a dynamic cross-chaotic encryption method applied to a smart grid in the present invention.

[0055] Please refer to Figure 1 , this embodiment provides a dynamic cross-chaotic encryption method applied to a smart grid. Based on the Logistic mapping equation, considering the influence of the encryption time and adjacent values, a dynamic cross-chaotic mapping equation is generated, including the following steps:

[0056] S100: Obtain the signal to be encrypted transmitted by the smart grid and the encryption time. The signal to be encrypted is a binary plaintext data stream.

[0057] It should be noted that the encryption time in this embodiment is the time of the Beidou timing system obtained through the Beidou time channel, which is the occurrence time of the signal to be encrypted in the smart grid (in this embodiment, seconds are taken, that is, 0 ≤ T sec < 60). The signal to be encrypted is represented in binary form.

[0058] S200: Use the dynamic cross-chaotic mapping equation to determine the encryption key stream. The encryption key stream does not include the initial value.

[0059] It should be noted that the dynamic cross-chaotic mapping equation in this embodiment is specifically determined by the following calculation formula:

[0060] When n = 0,

[0061] x n+1 = μx n (1 - x n ) (2)

[0062] When n > 0,

[0063] x n+1 = μx n (1 - x n ) + (1 - μ)ψ(T sec ) (3)

[0064] Among them, μ ∈ [0, 1], x0 ∈ [0, 1], ψ(t) is a dynamic cross-operator, serving as the real-time "perturbation" quantity of the chaotic system. is the cross coefficient, and T sec is the time of the aforementioned Beidou timing system.

[0065] The dynamic cross-chaotic mapping equation of this embodiment satisfies the following three basic characteristics:

[0066] ① Chaos has extreme sensitivity to the initial value;

[0067] ②The chaotic mapping has topological transitivity;

[0068] ③Although chaos has properties similar to random signals, it is a deterministic motion, and its motion trajectory is determined by the initial value and the chaotic mapping parameters.

[0069] Therefore, the dynamic cross-chaotic mapping equation theoretically meets the conditions for application in cryptography.

[0070] In the dynamic cross-chaotic mapping equation of this embodiment, ψ(T sec ) serves as a real-time "perturbation" quantity. The existence of the T sec variable causes this part of the value to be affected by the occurrence time of the encrypted signal and undergo dynamic changes. And compared with the traditional chaotic system in Equation (1), in the chaotic sequence, x n+1 is directly affected by x n , making the entire random sequence show a single chain-correlation structure form. While in the chaotic sequence of this embodiment, x n+1 is directly affected by the cross-influence of x n and x n-1 . Moreover, there is no definite weight coefficient between x n and x n-1 . Instead, the influence weights of the two are changed in real time through the dynamic cross-coefficient .

[0071] Based on the traditional chaotic equation, this embodiment greatly expands the state space of the chaotic orbit through the dynamic cross-operator ψ(T sec ). Starting from any point x of the chaotic system, it can quickly jump out of the mapping region of the traditional chaotic equation, further strengthening the ergodicity of the chaotic system.

[0072] S300: Perform an exclusive OR operation on the encrypted key stream and the signal to be encrypted to obtain the encrypted signal.

[0073] As Figure 2 shown, Figure 2 is a schematic flowchart of the dynamic cross-chaotic encryption in this embodiment. Among them, the general encryption process of generating the encrypted key stream using the dynamic cross-chaotic mapping is to perform a bitwise exclusive OR operation on the random sequence {x i} = x1, x2... x n (in the solution of the present invention, x0 generated by initialization is not regarded as a member of this random sequence, so {x i} starts from x1) as the key stream {k i} and the plaintext data stream {m i} to obtain the ciphertext data stream {c i}. The plaintext data stream is binary, and the key stream {k i} is for the chaotic sequence {xi} It is obtained by implementing data processing. The specific process is as follows (taking the encryption of two-byte plaintext as an example):

[0074] 1) Initialize the control parameter variable μ and the initial value x0, such as μ = 0.812 and x0 = 0.357;

[0075] 2) Obtain the occurrence time of the signal to be encrypted and take the seconds. It is assumed that the plaintext signals of these two bytes occur at the same moment, which is T sec = 27;

[0076] 3) Generate a set of random sequences using the dynamic cross-chaotic mapping equation, {x2} = {0.2546895264, 0.7244552474};

[0077] 4) Take M = 6, that is, take 6 significant digits of the random sequence to form an integer sequence: [254689, 724455];

[0078] 5) Take the remainder of each element of the integer sequence [254689, 724455] with respect to 256 to obtain two-byte keys [255, 231];

[0079] 6) Perform exclusive OR operations on the two keys of [255, 231] with the two-byte plaintext respectively to obtain the ciphertext.

[0080] This embodiment provides a dynamic cross-chaotic encryption method applied to smart grids, including obtaining the signal to be encrypted and the encryption moment transmitted by the smart grid; determining the encryption key stream using the dynamic cross-chaotic mapping equation. The dynamic cross-chaotic mapping equation introduces a dynamic cross operator on the basis of the Logistic mapping equation to generate an encryption key stream considering the influence of the encryption moment and adjacent key values; performing an exclusive OR operation on the encryption key stream and the signal to be encrypted to obtain the encrypted signal.

[0081] Due to the sensitive dependence of the chaotic system on the initial conditions (μ, x0), for initial values with only slight differences, the chaotic system will generate completely different chaotic sequences. In order to make the chaotic sequences of similar initial values more uncorrelated with each other, in this embodiment, through the dynamic cross operator ψ(T sec ), the error is effectively amplified, making the attack on the initial conditions ineffective. Encryption using this dynamic chaotic mapping can spread the plaintext to a more extensive ciphertext space, thus greatly increasing the brute-force attack threshold. In addition, since the cross coefficient varies dynamically, the unpredictability of the chaotic sequence can be greatly enhanced.

[0082] The above is a detailed introduction to an embodiment of the dynamic cross-chaotic encryption method applied to the smart grid in the present invention. Next, another embodiment of the dynamic cross-chaotic encryption system applied to the smart grid in the present invention will be introduced in detail.

[0083] This embodiment provides a dynamic cross-chaotic encryption system applied to the smart grid. Based on the Logistic mapping equation, a dynamic cross operator is introduced to generate a dynamic cross-chaotic mapping equation considering the influence of the encryption time and adjacent key values, including a signal acquisition unit, a key generation unit, and an encryption operation unit.

[0084] In this embodiment, the signal acquisition unit is used to acquire the signal to be encrypted and the encryption time transmitted by the smart grid, where the signal to be encrypted is a binary plaintext data stream.

[0085] In this embodiment, the key generation unit is used to determine the encryption key stream using the dynamic cross-chaotic mapping equation, and the encryption key stream does not include the initial value.

[0086] It should be noted that the dynamic cross-chaotic mapping equation is specifically determined by the following calculation formula:

[0087]

[0088] In the formula, ψ(t) is the dynamic cross operator, T sec is the encryption time, x n is the nth value in the random sequence, and μ is the control parameter variable.

[0089] Among them, the dynamic cross operator is specifically determined by the following calculation formula:

[0090]

[0091] In the formula, is the cross coefficient.

[0092] In this step, the key generation unit determines the encryption key stream using the dynamic cross-chaotic mapping equation, specifically including:

[0093] Initialize the control parameter variable μ and the initial value x0;

[0094] Generate a set of random sequences using the dynamic cross-chaotic mapping equation, and this random sequence does not include the initial value;

[0095] For each value in the random sequence, take M significant digits to form an integer Y, and take the remainder of the integer Y divided by 256 to obtain a one-byte key;

[0096] The one-byte keys corresponding to each value in the random sequence form the encryption key stream.

[0097] In this embodiment, the encryption operation unit is used to perform an exclusive OR operation on the encrypted key stream and the signal to be encrypted to obtain an encrypted signal.

[0098] It should be noted that the dynamic cross-chaotic encryption system provided in this embodiment is used to implement the dynamic cross-chaotic encryption method provided in the foregoing embodiment. The specific settings of each unit are based on the complete implementation of this method, and will not be elaborated here.

[0099] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dynamic cross-chaotic encryption method applied to the smart grid, characterized in that, Based on the Logistic mapping equation, considering the influence of the encryption moment and adjacent values, a dynamic cross-chaotic mapping equation is generated, including the following steps: Obtain the signal to be encrypted transmitted by the smart grid and the encryption moment, where the signal to be encrypted is a binary plaintext data stream; Generate an encryption key stream using the dynamic cross-chaotic mapping equation, and the encryption key stream does not include the initial value; Perform an exclusive OR operation on the encryption key stream and the signal to be encrypted to obtain an encrypted signal; The dynamic cross-chaotic mapping equation is specifically determined by the following calculation formula: where ψ(t) is the dynamic crossover operator, T sec is the encryption moment, x n and x n+1 are two adjacent values in the random sequence, n is a natural number, and μ is a control parameter variable; The dynamic cross-operator is specifically determined by the following calculation formula: In the formula, is the cross coefficient.

2. The dynamic cross-chaotic encryption method applied to the smart grid according to claim 1, characterized in that, Determining the encryption key stream using the dynamic cross-chaotic mapping equation specifically includes: Initialize the control parameter variable μ and the initial value x0; Generate a set of random sequences using the dynamic cross-chaotic mapping equation, and the random sequences do not include the initial value x0; For each value in the random sequence, take M significant digits to form an integer Y, and take the remainder of the integer Y divided by 256 to obtain a one-byte key; The one-byte keys corresponding to each value in the random sequence form the encryption key stream.

3. A dynamic cross-chaotic encryption system applied to the smart grid, characterized in that, Based on the Logistic mapping equation, considering the influence of the encryption moment and adjacent values, a dynamic cross-chaotic mapping equation is generated, including: A signal acquisition unit for obtaining the signal to be encrypted transmitted by the smart grid and the encryption moment; A key generation unit that generates an encryption key stream using the dynamic cross-chaotic mapping equation, and the encryption key stream does not include the initial value; An encryption operation unit for performing an exclusive OR operation on the encryption key stream and the signal to be encrypted to obtain an encrypted signal; The dynamic cross-chaotic mapping equation is specifically determined by the following calculation formula: where ψ(t) is the dynamic crossover operator, T sec is the encryption time, x n and x n+1 are two adjacent values in the random sequence, and μ is the control parameter variable; The dynamic cross-operator is specifically determined by the following calculation formula: In the formula, is the cross coefficient.

4. The dynamic cross-chaotic encryption system applied to the smart grid according to claim 3, characterized in that, The key generation unit determines the encryption key stream using the dynamic cross-chaotic mapping equation, specifically including: Initialize the control parameter variable μ and the initial value x0; Generate a set of random sequences using the dynamic cross-chaotic mapping equation, and the random sequences do not include the initial value x0; For each value in the random sequence, take M significant digits to form an integer Y, and take the remainder of the integer Y divided by 256 to obtain a one-byte key; The one-byte keys corresponding to each value in the random sequence form the encryption key stream.

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