Audio data encryption method based on chaotic sequence and cosine mapping

Abstract

The invention discloses an audio data encryption method based on a chaotic sequence and cosine mapping, and the method specifically comprises the following steps: S1, obtaining audio data to be encrypted, and splitting the audio data into an audio sequence; s2, performing sequence scrambling on the audio sequence to obtain a first sequence to be encrypted; s3, constructing a chaotic system to generate a chaotic sequence, and performing mapping encryption on the chaotic sequence to obtain a key sequence; and S4, performing XOR operation on the first to-be-encrypted sequence and the key sequence, and outputting an encrypted sequence.

Description

Technical Field

[0001] The present invention relates to the technical field of data security, and particularly to an audio data encryption method based on chaotic sequences and cosine mapping. Background Art

[0002] Existing audio encryption methods mainly focus on complex encryption algorithms, ignoring the consumption of computing resources and not considering the advantages of computer bit operations. As a result, the audio encryption process is complex, and it is even difficult to ensure the real-time performance of audio transmission.

[0003] Taking the patent "Chaos-based Bit-level Audio Encryption Method" with the application number 202010502531.6 as an example, this invention uses a chaotic system to generate a chaotic sequence, and then scrambles the audio data and performs an exclusive OR operation with one of the chaotic sequences to complete audio encryption. This scheme does not fully utilize the random characteristics of the chaotic sequence. Instead, it maps according to the amplitude sorting of the chaotic sequence to scramble the audio sequence, and finally only uses one variable sequence of the chaotic sequence to complete audio encryption. It involves sorting operations on sequences, with a large amount of calculation and high resource consumption, and cannot ensure the real-time performance of audio transmission.

[0004] Taking the patent "Multi-audio Encryption Method Based on Chaos and Zigzag Transformation" with the application number 202010502514.2 as an example, this invention uses a chaotic system to generate a chaotic sequence, and then uses a two-dimensional Zigzag transformation to scramble the audio data and performs an exclusive OR operation with one of the chaotic sequences to complete audio encryption. Although this scheme combines the two-dimensional Zigzag transformation with the chaotic sequence, it does not fully utilize the random characteristics of the chaotic sequence. It only uses one variable sequence of the chaotic sequence to complete audio encryption, and involves sorting operations on sequences, with a large amount of calculation and high resource consumption, and cannot ensure the real-time performance of audio transmission.

[0005] Taking the patent "Audio Encryption Method Based on DNA Convolution" with the application number 202210514672.9 as an example, this invention combines the randomness of the DNA convolution kernel and the chaotic sequence, and uses DNA convolution operations to achieve audio encryption. However, according to the patent description, for an audio sequence with a length of 73120, it will be converted into a 73120×8 DNA matrix, and the DNA convolution kernel is 8×8, so the complexity of DNA convolution operations is extremely high, and the real-time performance of audio transmission cannot be ensured. Summary of the Invention

[0006] Aiming at the problem of low security of audio data in the prior art, the present invention proposes an audio data encryption method based on chaotic sequences and cosine mapping. By using chaotic sequences to encrypt audio data, it can provide a higher level of privacy protection and ensure that sensitive audio information will not be accessed or stolen by unauthorized persons.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An audio data encryption method based on chaotic sequences and cosine mapping, specifically comprising the following steps:

[0009] S1: Obtain the audio data to be encrypted and split it into audio sequences;

[0010] S2: Perform sequence scrambling on the audio sequences to obtain the first sequence to be encrypted;

[0011] S3: Construct a chaotic system to generate a chaotic sequence, and perform mapping encryption on the chaotic sequence to obtain a key sequence;

[0012] S4: Combine the first sequence to be encrypted and the key sequence and output the encrypted sequence.

[0013] Preferably, the S1 includes:

[0014] S1-1: Obtain the audio data to be encrypted;

[0015] S1-2: Split the audio data to be encrypted into audio sequences.

[0016] Preferably, the S1-2 is specifically:

[0017] The audio data to be encrypted includes n audio samples;

[0018] Quantize each audio sample with 16 bits, and then split each sample into the high 8 bits and the low 8 bits to obtain the split samples;

[0019] Combine the n split samples to obtain the audio sequence S.

[0020] Preferably, the S2 includes:

[0021] S2-1: Calculate the audio sequences to obtain the corresponding inverse elements;

[0022] S2-2: Perform an affine transformation on the obtained inverse elements to obtain transformation parameters;

[0023] S2-3: Use the transformation parameters as output bytes to form entries in the S-box to obtain the first encrypted sequence D.

[0024] Preferably, in the S2-2, the formula for the affine transformation is:

[0025] w = A·θ + b (1)

[0026] In formula (1), w represents the transformation parameter; A is a fixed 8×8 linear transformation matrix; b is a constant vector, and θ represents the inverse element.

[0027] Preferably, S3 includes:

[0028] S3-1: Construct a chaotic system;

[0029] S3-2: Generate a chaotic sequence based on the constructed chaotic system;

[0030] S3-3: Map the chaotic sequence to a preset interval through a cosine mapping to obtain a mapped sequence;

[0031] S3-4: Perform 16-bit quantization on the mapped sequence to obtain the key sequence G.

[0032] Preferably, in S3-1, the chaotic system is:

[0033]

[0034] In formula (2), x, y, and z represent the state variables of the chaotic system.

[0035] Preferably, S3-2 includes:

[0036] S3-2-1: Pre-iterate the chaotic system N 1 times;

[0037] S3-2-2: Then iterate the chaotic system N 2 times to generate new state values A = {A x , A y , A z}, where

[0038] A x = {x 1 , x 2 ,..., x k}, A y = {y 1 , y 2 ,..., y k}, A z = {z 1 , z 2 ,..., z k}, 0 < k ≤ P; x k , y k ,

[0039] z k represent the state values of each variable in the k-th iteration of the chaotic system, and P represents the length of the sequence to be encrypted divided by 3;

[0040] S3-2-3: Adjust the order of the state variables according to the numerical changes of the state variable A to generate the chaotic sequence C = {C 1 , C 2 ,..., C k}.

[0041] Preferably, in the step S3-3, the objective function of the cosine mapping is as follows:

[0042] q = cos(T·ε + b) (3)

[0043] In formula (3), q represents the mapping sequence value; T is the frequency controlling the cosine function, b is the phase shift controlling the cosine function; ε represents the input value of the chaotic sequence.

[0044] Preferably, the step S4 includes:

[0045] First, perform exclusive OR operations on the high 8 bits and the low 8 bits of the first encryption sequence D and the key sequence G respectively to obtain a first calculation result and a second calculation result:

[0046] D n = {d 1 , d 2 ,..., d m / 2}, G n = {g 1 , g 2 ,..., g m / 2} (4)

[0047] In formula (4), D n represents the first calculation result; d m / 2 represents the binary bit of the first encryption sequence D n ; G n represents the second calculation result; g m / 2 represents the binary bit of the key sequence G;

[0048] Then, perform audio encryption on the first calculation result based on the exclusive OR operation:

[0049]

[0050] In formula (5), E n represents the encryption result, G kH represents the subsequence of the high m / 2 bits of the chaotic key sequence G; G kL represents the subsequence of the low m / 2 bits of the chaotic key sequence G; represents the exclusive OR operation.

[0051] In summary, due to the adoption of the above technical solutions, compared with the prior art, the present invention has at least the following beneficial effects:

[0052] The present invention combines a chaotic sequence and a cosine mapping, enhances the randomness and nonlinearity of the encryption sequence, avoids the problems of high computational complexity and large resource consumption in the prior art, and simultaneously realizes simple, efficient, and low-resource-consumption audio encryption.

[0053] Real-time optimization: By simplifying the algorithm complexity, reducing the consumption of computing resources, and improving the real-time performance of audio encryption and decryption, it is suitable for the fast processing requirements during transmission.

[0054] High security: Utilize an improved Lorenz chaotic system to generate a key sequence with high randomness and resistance to linear attacks, enhancing the protection of sensitive audio data.

[0055] Wide range of applications: The technical solution is applicable to multiple fields such as communication technology, network audio streams, military defense, and healthcare, covering the multi-scenario requirements from privacy protection to commercial applications.

[0056] Low-cost implementation: Implement the encryption algorithm in software, without the need for new hardware devices, reducing the implementation cost and being suitable for wide promotion. Brief Description of the Drawings

[0057] Figure 1 It is a schematic diagram of an audio data encryption method based on a chaotic sequence and cosine mapping according to an exemplary embodiment of the present invention.

[0058] Figure 2 It is a schematic diagram of the splitting of audio data according to an exemplary embodiment of the present invention. Detailed Embodiment

[0059] The present invention will be further described in detail below in conjunction with embodiments and specific implementation manners. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. Any technology implemented based on the content of the present invention belongs to the scope of the present invention.

[0060] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

[0061] In the description of the present invention, unless otherwise specified and defined, it should be noted that the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0062] Such as Figure 1As shown in the figure, the present invention provides an audio data encryption method based on chaotic sequences and cosine mapping, which specifically includes the following steps:

[0063] S1: Obtain the audio data to be encrypted and split it into audio sequences.

[0064] S1-1: Obtain the audio data to be encrypted.

[0065] In this embodiment, the audio data is in units of frames. Usually, 10 ms of samples are taken as one frame, and it can also be set by itself. Usually, the length of one frame does not exceed 20 ms. Taking 16 kHz sampling as an example, 10 ms represents 160 samples.

[0066] S1-2: Split the audio data to be encrypted into audio sequences.

[0067] As Figure 2 shown, each audio sample is quantized with 16 bits. For the convenience of subsequent processing, each sample is split into the high 8 bits and the low 8 bits to obtain the audio sequence S.

[0068] The audio data to be encrypted includes N samples. The original audio samples are quantized with 16 bits. After being split into two 8-bit parts, the sequence length becomes 2N. Then the length D of the first encrypted sequence after calculation should be 2N.

[0069] In this embodiment, the structure of each sample is the same. Therefore, the first sample is used as an example for illustration. After quantizing the first sample with 16 bits, it is {15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0}. Then the first sample is split into the high 8 bits {15, 14, 13, 12, 11, 10, 9, 8} and the low 8 bits {7, 6, 5, 4, 3, 2, 1, 0}, thereby forming the first split sample.

[0070] By analogy, the second split sample, the Nth split sample can be obtained. Combining all the split samples can obtain the audio sequence S.

[0071] S2: Based on the AES encryption algorithm, perform sequence scrambling on the audio sequence to obtain the first sequence to be encrypted.

[0072] S2-1: Calculate the audio sequence in the finite field GF(2 8 ) based on the AES encryption algorithm to obtain the corresponding inverse element.

[0073] For each input byte (referring to the audio sequence output by S1), first find its inverse element in the finite field GF(2 8 ) to construct the S-box. The inverse element means that for a given element x, there exists an element x -1 , such that their product is 1, that is: x·x-1 = 1.

[0074] In this embodiment, the S-Box (Substitution Box) is an important component in the AES algorithm. It increases the complexity of the cipher by applying a non-linear substitution operation to each data block (byte), making the encryption more difficult to break through simple linear analysis.

[0075] The AES encryption process includes multiple steps, and one of them is to use the S-Box for scrambling. In the AES algorithm, the role of the S-Box is to perform byte substitution operations during the encryption process, replacing each input byte (a number between 0 and 255) with a new byte to form a new data block.

[0076] 1. Structure of the S-Box

[0077] AES uses a fixed S-Box for byte substitution operations. This S-Box is a non-linear substitution table that maps each byte (8 bits, 0 to 255). The design of the S-Box is based on a mathematically irreversible function. Specifically, it uses the inverse element operation on GF(2^8) (finite field) and an affine transformation.

[0078] The construction process of the S-Box includes the following steps:

[0079] Inverse element: First, the input value of the AES S-Box is regarded as an element on GF(2^8), and the inverse element of this element is calculated first (in the finite field).

[0080] Affine transformation: Then, the inverse element undergoes an affine transformation (linear transformation plus a constant) to obtain the final S-Box output.

[0081] 2. Construction Process of the S-Box

[0082] Suppose we want to encrypt a byte x (the value range is 0 to 255). First:

[0083] Regard x as an element in the finite field GF(2^8).

[0084] Perform an inverse operation on x to obtain its inverse element in GF(2^8).

[0085] Perform an affine transformation on the obtained inverse element to obtain the S-Box output through a predefined matrix and constant.

[0086] The design of the S-Box makes the relationship between its output and input highly non-linear, which guarantees the security of AES.

[0087] 3. S-Box Scrambling in AES

[0088] During the encryption process of AES, the S-box scrambling appears in the SubBytes step. This step operates on each byte as follows:

[0089] SubBytes: For each byte x, look up the corresponding value S(x) in the S-box and replace the original byte with the value at the corresponding position in the S-box. The purpose of this step is to break the linear structure of the input bytes and make the ciphertext more random.

[0090] For example, if the input block contains the byte 0x32, after looking it up in the S-box, it may be replaced with 0x87. This byte substitution is irreversible, thus increasing the strength of the cipher.

[0091] 4. Application of S-box in the AES Encryption Process

[0092] During the encryption process of AES, the S-box scrambling is achieved through multiple rounds of the SubBytes step. In each round, the input data (data block) is decomposed into multiple bytes, and each byte is replaced through the S-box. The specific process is as follows:

[0093] Initial Round Key Addition (AddRoundKey): Perform an exclusive OR operation on the input data and the round key.

[0094] SubBytes: Apply S-box substitution (scrambling) to each byte.

[0095] ShiftRows: Perform a cyclic shift on the data rows.

[0096] MixColumns (only in all rounds except the last round): Perform a matrix transformation on the data columns to increase the diffusion of the data.

[0097] AddRoundKey: Perform an exclusive OR operation with the round key again.

[0098] These steps are repeated multiple times until the final encrypted ciphertext is obtained.

[0099] In this embodiment, the core design of the S-box is to enhance the non-linearity of encryption. In the AES algorithm, the role of the S-box scrambling is as follows:

[0100] Improve cipher complexity: By replacing the input bytes with other bytes, the S-box disrupts the data structure, making the relationship between the output and the input very complex. Without the appropriate key, it is impossible to predict the output value.

[0101] Enhance anti-attack ability: The non-linear characteristics of the S-box are crucial for resisting linear attacks, differential attacks, and other mathematical attacks.

[0102] Increase encryption strength: The S-box provides an irreversible transformation, making it difficult to reverse-engineer the original data or key even when analyzing certain bytes during the encryption process.

[0103] The S-box design of AES highly emphasizes security and employs many mathematical techniques to ensure strong anti-attack capabilities. The S-box design enhances security in the following ways:

[0104] Unpredictability: The S-box is carefully designed to ensure that the output of each byte substitution operation is unpredictable, reducing direct inference of the original data.

[0105] Resistance to differential attacks: Differential attack is a method of cracking the key by analyzing the differences between the input and output during the encryption process. The S-box of AES avoids patterns that are easily exploited by differential attacks during design, thus enhancing its resistance to differential attacks.

[0106] Resistance to linear attacks: Linear attacks rely on finding linear relationships between the input and output. The highly non-linear substitution behavior of the S-box of AES makes such attacks very difficult.

[0107] In this embodiment, calculating the inverse element of the input byte requires using the multiplication rule of the finite field GF(2 8 ) and is achieved by solving a specific polynomial (which is prior art and will not be elaborated here).

[0108] In this embodiment, in the finite field GF(2 8 ), the zero element 0x00 has no inverse element. Therefore, during the construction of the S-box, the zero element is specially processed and usually mapped to a fixed value 0x63 to avoid errors.

[0109] S2-2: Perform an affine transformation on the obtained inverse element to obtain transformation parameters.

[0110] In this embodiment, a fixed linear affine transformation is used to further scramble the structure of the inverse element. The formula for the affine transformation is:

[0111] w = A·θ + b (1)

[0112] In formula (1), w represents the transformation parameter; A is a fixed 8×8 linear transformation matrix; b is a constant vector, and θ represents the inverse element. The purpose of the affine transformation is to enhance the unpredictability and resistance to linear attacks of the S-box, making the output of the S-box not easily derivable through simple linear relationships.

[0113] S2-3: Use the transformation parameter as the new output byte to form an entry in the S-box.

[0114] In this embodiment, after the above steps (S2-1, S2-2, S2-3), an output byte corresponding to each input byte (from 0 to 255) is generated. The entire S-box is a lookup table of size 256, which contains the mapping from the input byte to the output byte. In this way, the scrambling operation of the audio sequence is realized, which is also the primary encryption of the audio sequence, and the first encrypted sequence D is obtained.

[0115] S3: Construct a chaotic system to generate a chaotic sequence, and perform mapping encryption on the chaotic sequence to obtain a key sequence.

[0116] S3-1: Construct a chaotic system.

[0117] Chaos phenomenon is a deterministic and pseudo-random process manifested in nonlinear dynamic systems. This process is neither periodic nor convergent, and has a sensitive dependence on the initial value. Its behavior is characterized by uncertainty, non-repeatability, and unpredictability.

[0118] Based on the three-dimensional improved Lorenz chaotic system, the present invention constructs a new three-dimensional chaotic system:

[0119]

[0120] In formula (2), x, y, and z represent the state variables of the chaotic system. The Lyapunov exponents can be calculated to determine whether the system has chaotic characteristics. Since the Lyapunov exponent is an important index for quantifying the sensitivity of the system to the initial conditions, a positive Lyapunov exponent indicates that the system has exponential sensitivity to small changes in the initial conditions, and this behavior is a typical characteristic of a chaotic system.

[0121] For the constructed chaotic system, through numerical analysis, the calculated Lyapunov exponents are (2.1693, 0, -20.1667), that is, the constructed chaotic system has chaotic characteristics. The present invention generates a chaotic sequence based on this new chaotic system.

[0122] S3-2: Generate a chaotic sequence based on the constructed chaotic system.

[0123] Due to the high randomness and complexity of the chaotic system, the chaotic sequence is transformed into the required form through a specific quantization algorithm, which enhances the security of the encryption algorithm. The specific operations are as follows:

[0124] S3-2-1: Pre-iterate the chaotic system N 1 times to eliminate the transient influence of the chaotic system entering the chaotic state.

[0125] S3-2-2: Then iterate the chaotic system N2 Next, generate a new set of state values \(A = \{A x , A y , A z \}\), where \(A x =\{x 1 , x 2 , \cdots, x k \}\), \(A y =\{y 1 , y 2 , \cdots, y k \}\), \(A z =\{z 1 , z 2 , \cdots, z k \}\), \(0 \lt k\leq P\); \(x k \), \(y k \), \(z k \) represent the state values of each variable in the \(k\)-th iteration of the chaotic system, and \(P\) represents the length of the sequence to be encrypted divided by 3.

[0126] S3 - 2 - 3: According to the numerical change of the state variable \(A\), adjust the order of the state variables to generate a chaotic sequence \(C=\{C 1 , C 2 , \cdots, C k \}\), \(C k \) represents the chaotic result of the \(k\)-th iteration of the chaotic system. The mapping relationship between the sorting rule of the chaotic sequence \(C\) and the state variable \(A\) is shown in Table 1.

[0127] Table 1 Mapping relationship between the sorting rule of the chaotic sequence \(C\) and the state variable \(A\)

[0128]

[0129] S3 - 3: Map the chaotic sequence to a preset interval to obtain a mapped sequence.

[0130] Since the value range of the chaotic sequence generated by S3 - 2 is relatively large and it cannot be effectively controlled within the range of \([0, 1]\), this will have an adverse impact on the next chaotic encryption (in the XOR operation, the input value range is preferably between \([0, 1]\), which can avoid the scaling problem of detecting the input value). Therefore, in this step, the input value of the chaotic sequence is mapped to the specified interval \([0, 1]\) through the cosine mapping function, and the nonlinearity of the chaotic sequence can be further improved.

[0131] The objective function of the cosine mapping is as follows:

[0132] q = \cos(T\cdot\varepsilon + b)\ (3)

[0133] In formula (3), q represents the mapping sequence value; T is the frequency that controls the cosine function, and b is the phase shift that controls the cosine function. By adjusting the parameter T, the periodicity and complexity of the generated sequence can be changed. A larger T will result in faster changes, making the generated random number sequence have a shorter period, while a smaller T will result in slower sequence changes and a longer period. Usually, T takes the value of 2 or 3; the parameter b determines the starting point of the mapping and usually takes the value of π / 2; ε represents the input value of the chaotic sequence.

[0134] S3-4: Quantize the mapping sequence to 16 bits to obtain the key sequence G.

[0135] S4: To demonstrate the simplicity and non-linear advantages of the chaotic key implementation, give full play to the advantages of the ciphertext interleaving diffusion technology in audio encryption, and improve its ability to resist illegal attacks, the present invention uses the exclusive OR operation method for audio encryption. Its characteristics are applicable to audio signal encryption, non-linear ciphertext, easy to implement, and can improve the ciphertext diffusion speed.

[0136] Perform exclusive OR operations on the high 8 bits and low 8 bits of the first encryption sequence D and the key sequence G respectively to obtain the first calculation result and the second calculation result:

[0137] D n = {d 1 , d 2 ,..., d m / 2}, G n = {g 1 , g 2 ,..., g m / 2} (4)

[0138] In formula (4), D n represents the first calculation result, and the value range of n is [1, 2N]; d m / 2 represents the binary bit of the first encryption sequence D n ; G n represents the second calculation result; g m / 2 represents the binary bit of the key sequence G; m = 16;

[0139] For example, if D n is 8 bits, it is represented as {d 1 , d 2 ,..., d 8}, and the values of d 1 , d 2 ,..., d 8 are 0 or 1. Since the operation of equation (5) is bitwise exclusive OR operation, this is for convenient description.

[0140] Then, based on the exclusive OR operation, encrypt the first calculation result to obtain the encrypted result, and concatenate each encrypted result to obtain the encrypted sequence:

[0141]

[0142] In formula (5), E n represents the encrypted result, G kH represents the high m / 2-bit subsequence of the chaotic key sequence G; G kL represents the low m / 2-bit subsequence of the chaotic key sequence G; represents the exclusive OR operation.

[0143] The present invention has at least the following advantages:

[0144] Audio privacy protection: By using chaotic sequences to encrypt audio data, a higher level of privacy protection can be provided to ensure that sensitive audio information cannot be accessed or stolen by unauthorized persons;

[0145] Secure communication: In audio communication, such as phone calls or audio chats, chaotic sequence encryption can prevent eavesdroppers from listening to the communication content, thereby protecting the confidentiality of the communication;

[0146] Prevent audio data leakage: Chaotic sequence encryption can help prevent audio data from being stolen by malicious accessors or hackers during transmission or storage, thereby protecting the confidentiality of audio content.

[0147] In the privacy protection of key data of robots, the audio data encryption method based on chaotic sequences and cosine mapping can effectively protect user privacy. The method not only ensures the efficiency and real-time nature of the encryption process, but also effectively prevents unauthorized accessors from eavesdropping on or tampering with sensitive voice commands, ensuring the security and integrity of the data.

[0148] In national defense and military communications, military command centers need to coordinate and communicate with various units and personnel deployed in key military operations. During these communication processes, it is necessary to securely exchange highly confidential and time-sensitive information, such as troop movements, mission plans, and strategic orders. To ensure the maximum security of these communications, the military uses chaotic sequence technology for audio encryption.

[0149] In the field of multimedia playback, music streaming services provide platforms for users to stream and share music. The service offers premium subscription tiers that allow users to access a vast library of high-quality audio tracks. To protect the integrity of audio content, ensure artists' royalties, and protect user privacy, the streaming service uses patented technology based on chaotic sequences for audio encryption.

[0150] The present invention can also be used in the following technical fields:

[0151] Communication technology: This technology can be used to encrypt phone calls, audio chats, and other forms of communication to ensure the confidentiality of communication content, and is applicable to mobile phones, VoIP systems, and communication devices;

[0152] Network audio streaming: Used in areas such as online music, video conferencing, and streaming services to protect audio content from unauthorized access;

[0153] Military and national defense: In the field of military communication and intelligence, it is crucial to protect the security of sensitive audio information. This technology can be applied to military communication devices and intelligence transmission;

[0154] Healthcare: Used to encrypt audio data in medical records to ensure patient privacy, especially in the fields of telemedicine and electronic health records;

[0155] Law and law enforcement: Used to protect recorded evidence to ensure the integrity and security of audio evidence used in court;

[0156] Enterprise and business: In the business field, it can be used to protect the privacy of sensitive business meetings and phone calls, as well as encrypt audio conference and training content;

[0157] Education: Used to encrypt audio course content on online education platforms to ensure the protection of intellectual property and educational resources.

[0158] Those of ordinary skill in the art can understand that the above embodiments are specific examples for implementing the present invention, and in practical applications, various changes can be made to them in form and details without departing from the spirit and scope of the present invention.

Claims

1. An audio data encryption method based on chaotic sequence and cosine mapping, characterized in that: The specific steps include: S1: Obtain the audio data to be encrypted and split it into audio sequences; S2: Scrambling the audio sequence to obtain a first sequence to be encrypted; S3: construct a chaotic system to generate a chaotic sequence, and map and encrypt the chaotic sequence to obtain a key sequence; S4: Combine the first sequence to be encrypted and the key sequence, and output the encrypted sequence.

2. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 1, characterized in that: The S1 includes: S1-1: Obtain audio data to be encrypted; S1-2: Split the audio data to be encrypted into audio sequences.

3. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 2, characterized in that: The S1-2 is specifically: The audio data to be encrypted includes n audio samples; Quantize each audio sample to 16 bits, and then split each sample into high 8 bits and low 8 bits to obtain split samples; The n split sample sets are used to obtain the audio sequence S.

4. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 1, characterized in that: The S2 includes: S2-1: Calculate the audio sequence to obtain the corresponding inverse element; S2-2: Perform affine transformation on the obtained inverse element to obtain transformation parameters; S2-3: Use the transformation parameters as output bytes to form entries in the S-box, and obtain the first encryption sequence D.

5. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 4, characterized in that: In S2-2, the formula of affine transformation is: w=A·θ+b (1) In formula (1), w represents the transformation parameter; A is a fixed 8×8 linear transformation matrix; b is a constant vector, and θ represents the inverse element.

6. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 1, characterized in that: The S3 includes: S3-1: Constructing a chaotic system; S3-2: Generate chaotic sequences based on the constructed chaotic system; S3-3: Mapping the chaotic sequence to a preset interval by cosine mapping to obtain a mapping sequence; S3-4: quantize the mapping sequence to 16 bits to obtain the key sequence G.

7. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 6, characterized in that: In S3-1, the chaotic system is: In formula (2), x, y, and z represent the state variables of the chaotic system.

8. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 6, characterized in that: The S3-2 includes: S3-2-1: pre-iterate the chaotic system N1 times; S3-2-2: Then iterate the chaotic system N2 times to generate a new state value A = {A x ,A y ,A z },in, FLUENT x {x1,x2,...,x k },FLUENT y {y1,y2,...,y k },FLUENT z {z1,z2,...,z k },0 <k≤P;x k 、y k 、 z k represents the state value of each variable of the chaotic system at the kth iteration, and P represents the length of the sequence to be encrypted divided by 3; S3-2-3: According to the value change of state variable A, adjust the order of state variables to generate chaotic sequence C = {C1, C2, ..., C k }.

9. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 6, characterized in that: In S3-3, the objective function of the cosine mapping is as follows: q=cos(T·ε+b) (3) In formula (3), q represents the mapping sequence value; T is the frequency of the control cosine function; b is the phase offset of the control cosine function; ε represents the input value of the chaotic sequence.

10. The audio data encryption method based on chaotic sequence and cosine mapping as claimed in claim 1, characterized in that: The S4 includes: First, perform XOR operations on the high 8 bits and low 8 bits of the first encryption sequence D and the key sequence G to obtain the first calculation result and the second calculation result: D n ={d1,d2,...,d m / 2 },G n ={g1,g2,...,g m / 2 } (4) In formula (4), D n represents the first calculation result; d m / 2 Represents the first encryption sequence D n The binary bit of G n Indicates the second calculation result; g m / 2 Represents the binary bit of the key sequence G; Then the first calculation result is encrypted based on the XOR operation: In formula (5), E n Indicates the encryption result, G kH represents the high m / 2-bit subsequence of the chaotic key sequence G; G kL represents the lower m / 2 bit subsequence of the chaotic key sequence G; Represents the exclusive-or operation.

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