10 results about "Chaotic map" patented technology

The invention relates to a computer-based image encryption method using a Bessel map with high chaotic performance, which is developed to fill the gaps between a high performance chaotic map and a simple encryption scheme.

The invention relates to the field of image encryption, in particular to a chaos image encryption method based on DNA coding, which comprises the following steps: S1, calculating a hash value of a plaintext grayscale image by using a hash algorithm, and generating an initial key based on the hash value, S2, iterating a chaos sequence by using the initial key as an initial value and a control parameter of an iteration variable of two-dimensional chaos mapping 2D-CSMM, performing segmentation and quantization processing on the chaotic sequence to obtain a quantization matrix; performing reduction XOR operation on the quantization matrix to obtain a bit matrix; performing scrambling processing on a plaintext grayscale image based on the quantization matrix and the bit matrix to obtain a ciphertext image; s5, performing DNA diffusion processing on the ciphertext image based on the quantization matrix and the bit matrix to obtain an encrypted image; s6, decrypting the encrypted image according to the inverse process of image encryption to obtain a decrypted image; according to the encryption method provided by the invention, the security of image encryption is greatly improved, and the security performance and the encryption effect are good.

The invention relates to the technical field of image encryption, in particular to a block compressed sensing-combined chaotic image encryption method, which comprises the following steps of: S10, acquiring a plaintext grayscale image, calculating a hash value of the plaintext grayscale image by using an SHA-512 algorithm and generating an initial secret key; s20, constructing a measurement matrix required by block compressed sensing and a chaos sequence and a matrix required by an image encryption algorithm by using the chaos sequence iterated by the two-dimensional composite chaos mapping and the initial secret key; s30, performing block processing on the plaintext grayscale image P, measuring each image block by using the measurement matrix, and combining the processed blocks into a new matrix; s40, the new matrix is subjected to scrambling operation based on DNA and S-box, and a ciphertext is obtained; s50, performing diffusion operation on the ciphertext to obtain a final encrypted image CI; s60, decrypting the encrypted image according to an inverse process of image encryption, and reconstructing the decrypted image by using an SL0 algorithm to obtain a final reconstructed image; the algorithm has good safety performance.

This invention belongs to the field of digital image encryption technology and discloses a selective encryption method for chaotic images based on facial recognition and key optimization. The method includes the following steps: Based on an existing chaotic mapping system model, an exponential term and a modulo function are added to optimize the system model's performance, establishing a three-dimensional amplitude-limited coupled hyperchaotic mapping system model; based on the three-dimensional amplitude-limited coupled hyperchaotic mapping system model, a color image face encryption scheme is designed. This invention employs the aforementioned selective encryption method for chaotic images based on facial recognition and key optimization to establish a three-dimensional amplitude-limited coupled hyperchaotic mapping system model, selectively encrypting facial regions, resulting in a wide range of chaos and high complexity; it adopts a face recognition encryption scheme based on the DeepFace model to effectively improve encryption speed; and it uses the PSO optimization algorithm to effectively resist known plaintext attacks, offering significant advantages in computational efficiency and encryption quality compared to traditional encryption methods.

The invention relates to the technical field of communication, in particular to a method for generating an optimal wide-interval frequency hopping sequence based on a genetic algorithm, which comprises the following steps of: generating an initial population by utilizing Bernoulli chaotic mapping; calculating the maximum Hamming autocorrelation function value of individuals in the initial population or the excellent population obtained by the last iteration, and calculating the fitness of the individuals; based on the fitness of the individuals, the probability that the individuals are selected as a parent population is calculated, and the individuals meeting the requirements are selected as the parent population based on the probability; two individuals are randomly selected from the parent population each time, and the individual with the lowest Hamming autocorrelation is directly added into the excellent population obtained through the iteration; or after recombination operation and / or mutation operation are / is carried out on the selected two individuals, the individual with the lowest Hamming autocorrelation is added into the excellent population obtained through iteration of this time. According to the method, the genetic algorithm is adopted to generate the optimal wide-interval frequency hopping sequence, the characteristics of global search and self-adaptive optimization can be fully utilized, and quick optimization is carried out in a large search space.

The present application relates to the field of image encryption, and particularly relates to a chaotic image encryption method based on DNA coding, S1: a hash value of a plaintext grayscale image is calculated by using a hash algorithm, and an initial secret key is generated based on the hash value, S2: the initial secret key is used as an initial value and a control parameter of an iteration variable of a two-dimensional chaotic mapping 2D-CSMM, a chaotic sequence is iterated out, the chaotic sequence is subjected to segmentation and quantization processing to obtain a quantization matrix, the quantization matrix is subjected to a reduction exclusive-OR operation respectively to obtain a bit matrix, and a plaintext grayscale image is subjected to a scrambling processing based on the quantization matrix and the bit matrix to obtain a ciphertext image, S5: the ciphertext image is subjected to a DNA diffusion processing based on the quantization matrix and the bit matrix to obtain an encrypted image, and S6: the encrypted image is decrypted according to an inverse process of image encryption to obtain a decrypted image, the encryption method provided by the present application greatly improves the security of image encryption, and has good security performance and encryption effect.

With the popularity of the Internet and cloud computing technology, image data in the process of transmission and storage is facing unauthorized access, malicious tampering and data theft and other security threats. In order to protect the image information from being stolen and improve the security in the process of network transmission, the application proposes an image scrambling method based on dynamic Joseph ring. First, a one-dimensional chaotic map is used to generate a pseudo-random sequence with high randomness and is integerized; second, the original image I is processed by vector flattening, the Joseph ring structure is constructed and dynamic Joseph scrambling is performed; finally, the pixel sequence after scrambling is reconstructed into a two-dimensional image matrix to obtain the encrypted image E . Experimental results show that the method has strong security and good encryption effect, which can ensure the security of image information in the process of network transmission.

The invention provides a chaotic image encryption method based on magic cube three-dimensional space diagonal rotation and Josephus transformation, and the method comprises the steps: generating a chaotic sequence through a memristor chaotic system, generating a chaotic pseudo-random integer sequence needed by encryption through integer processing, and carrying out the preprocessing of R, G and B channels of a plaintext image, so as to achieve the preliminary diffusion; converting the preprocessed two-dimensional image matrix into a three-dimensional magic cube structure, dynamically controlling a rotating surface and the number of rotating layers through a chaos pseudo-random integer sequence, and performing magic cube three-dimensional space diagonal rotation scrambling on the three-dimensional magic cube structure; the starting point, the counting period and the counting direction of the Josephus conversion scrambling are dynamically controlled by a chaos pseudo-random integer sequence, and the improved Josephus conversion scrambling is carried out; converting the scrambled three-dimensional matrix into a two-dimensional matrix, and performing XOR on the two-dimensional matrix and a chaos matrix generated by Logistic mapping to finish second-step diffusion; and synthesizing the diffusion matrixes of the R channel, the G channel and the B channel into a ciphertext image. The encryption effect of the color image can be improved.

The application relates to the field of information security and image protection technology, and provides a non-adjacent coupling chaotic image encryption method, a decryption method and a system based on two-stage optimization, the encryption method comprising the following steps: performing two-stage evolutionary parameter optimization to obtain optimal parameters, in the first stage, performing global benchmark parameter optimization by using a differential evolution algorithm, and in the second stage, performing grid level heterogeneous parameter optimization based on a covariance matrix adaptive evolution strategy; performing plaintext correlation key generation operation and completing system parameter initialization configuration; generating a chaotic sequence fused with the optimized parameters; performing row and column overlapping double scrambling operation; performing interlaced diffusion processing on the chaotic sequence, and outputting the final ciphertext. The scheme not only greatly improves the chaotic complexity and the anti-attack ability of the system, but also satisfies the cryptographic security threshold of the key space, can effectively resist various password attacks such as differential attacks and statistical analysis, and can be applied to image data protection in high-security scenes.

This invention relates to a DVS data encryption method, decryption method, apparatus, and system, comprising: acquiring an original event stream E; using an initial key parameter K to drive a one-dimensional chaotic map and LIF neurons, extracting the chaotic pulse intervals corresponding to adjacent firing pulses of LIF neurons, and performing least significant bit purification processing to generate a binary key stream KS; based on the binary key stream KS, using Fisher-Yates shuffling traversal to generate a time rearrangement mapping table and a spatial permutation mapping table; sequentially extracting events from the original event stream E, using the binary key stream KS as the overall driver, relying on the time rearrangement mapping table and the spatial permutation mapping table to complete global scrambling of timestamps, one-dimensional flattening and permutation of spatial coordinates, and combining the binary key stream KS to generate a key mask, completing event polarity reversal, and obtaining an encrypted event stream E'. This invention can reduce system latency and reduce computational resources.