38results about How to "Resist Brute Force Attacks" patented technology

The invention relates to an image compression and encryption method based on wavelet transform and SHA-1 (secure has algorithm-1) and aims to encrypt in image compression process. According to the algorithm, an image is subjected to four-layer wavelet decomposition first, and coefficients are divided into a low-frequency portion and a high-frequency portion after decomposition. Low-frequency coefficients, initial keys and original image pixels are used to generate 160-bit hashed values by SHA-1, and the hashed values generate subkey scrambled high-frequency coefficients. The scrambled high-frequency coefficients are subjected to SPIHT (set partitioning in hierarchical trees) encoding, and the initial keys disturbed by the hashed values are used to partially encrypt encoded data streams. Part of the encrypted high-frequency coefficients and the initial keys are used as input messages for SHA-1. The subkey scrambled low-frequency coefficients are generated by the hashed values, the scrambled low-frequency coefficients are subjected to Huffman encoding, and then the initial keys are disturbed by the hashed values to encrypt the encoded data streams, so that low-frequency coefficients are encrypted. Input information is sensitized by SHA-1, the low-frequency portion and the high-frequency portion are mutually encrypted, and accordingly image information safety is guaranteed.

The invention relates to a quantum chaos-based parallel image encryption method. The invention aims to solve the defects of a current traditional serial chaotic encryption algorithm. According to the method of the invention, a sequence generated by hyperchaotic Lorenz mapping and Chen mapping is used as an input sequence for parallel encryption; a generated intermediate ciphertext is adopted as the input of quantum logistic mapping; three-dimensional Baker scrambling operation is performed; and therefore, plaintext information can be hidden. As indicated by experimental simulation, the encryption speed of the algorithm of the invention is higher than that of the traditional serial encryption algorithm, the algorithm of the invention can effectively resist statistical attacks and differential attacks to achieve a very good encryption effect.

The present invention relates to a DNA dynamic coding based colored image encryption method, comprising: obtaining a key through a colored plain-text image; by the key, calculating an initial value and a parameter of a chaotic system used in scrambling and diffusion processes; substituting the initial value and the parameter to the chaotic system for iteration to obtain W1 and W2, obtaining a scrambling matrix K from W1, obtaining an integer matrix Y and an index matrix Ind from W2, and performing DNA coding on Y according to the index matrix Ind; and performing scrambling on the plain-text image row by row by using the matrix K, then performing coding and diffusion until all rows finish DNA coding, and finally performing decoding and recomposing on a DNA matrix, to obtain a final colored ciphertext image. According to the method, a function SHA256 is used to generate the key, so that the key space is expanded; the generation of the key depends on a plain-text, so that plain-text attack can be effectively resisted; chaotic characteristics are combined with DNA dynamic coding, so that the security is further improved; and meanwhile, scrambling and diffusion operations are performed according to the row of images, so that parallel computing is facilitated and the efficiency is improved.

The invention discloses a multi-image encryption method based on log-polar transform. The method comprises the following steps of: with log-polar transform, encoding different images to different annular ranges, wherein the inner and outer radiuses of the different annular ranges are not overlapped; and superposing all annular images to obtain one image; and performing double-random phase encoding encryption on the superposed image on the basis of fractional Fourier transform in an optical mode, wherein the transform order of the fractional Fourier transform and the random phase template are used as keys and the inner diameter and outer diameter of the transform annular area can be used as secondary keys. The method disclosed by the invention is simple and easy to operate, improves the image encryption efficiency, and has relatively good attack resistance and relatively high safety.

The invention relates to a color image encryption method based on an SHA-384 function, a spatiotemporal chaotic system, a quantum chaotic system and a neural network. The method includes the steps that an original color image I0 is calculated through the SHA-384 function, a Hash value is obtained as a secret key, the Hash value, a CML and one-dimension Logistic chaotic mapping are utilized for generating a chaos sequence, bit-level line-column scrambling is carried out on high four-digit images of components of three primary colors of the I0 through the chaos sequence, and a scrambled image I1 is obtained; the Logistic quantum chaotic system is utilized for generating a chaos sequence for encrypting the scrambled image, and is combined with the neural network to carry out parallel diffusion processing on all pixel values of components of three primary colors of the I1, and a final encrypted image I2 is obtained. By the method, the space of the secret key is greatly enlarged, the safety, encryption effect and secret key sensibility are higher, the attack resistance capacity is higher, the scrambling process and the encryption time are shorter, and hardware implementation is easier.

The invention relates to a color image encryption method based on Latin square scrambling. Plaintext keys r1, g1 and b1 are calculated through utilization of R, G and B components of a color plaintextimage, an initial value and a parameter obtained through calculation based on the keys are substituted into a chaotic system, and three groups of chaotic sequences are generated; the chaotic sequences for scrambling and diffusion are selected through utilization of a chaotic sequence selection mechanism based on the plaintext and digital arrangement; and a final ciphertext image is obtained through adoption of a block scrambling policy based on a Latin square and the chaotic sequences, and diffusion operation based on the plaintext and a scrambled image. The encryption method is closely related to the plaintext, so the plaintext attack resistance is improved. The employed chaotic system is an improved chaotic system, a chaotic characteristic is good, the randomness is high and a key spaceis great, so a security level is further improved. A simulation result and safety analysis show that according to the encryption provided by the invention, an image complete encryption demand can besatisfied, the encryption efficiency is high, and the robustness is high.

The invention relates to an image encryption method based on hyperchaotic system key dynamic selection, which mainly includes the following steps: arranging the original plaintext images into an image array P, and then using the hyperchaotic system to generate chaotic sequences and grouping them; combining the plaintext-dependent KSSG and KS dynamic selection mechanism to generate forward scrambling key K1, and perform forward scrambling on P to obtain P1; combine KSSG and KS mechanism to generate forward diffusion key K2, and perform forward diffusion on P1 to obtain P2; combine KSSG and KS The dynamic selection mechanism generates reverse scrambling key K3, reverse scrambles P2 to obtain P3; uses KSSG and KS dynamic selection mechanism to generate reverse diffusion key K4, performs reverse diffusion on P3 to obtain P4, and reorganizes P4 That is, the final ciphertext image is obtained. The above method increases the key space, makes the security, the encryption effect and the key sensitivity higher, the anti-attack ability is stronger, and it is easier to realize by hardware.

The invention discloses an automobile license plate with an encrypted QR two-dimensional code, which is characterized in that the front of the automobile license plate contains an encrypted QR two-dimensional code ciphertext image and a license plate number text. The automobile license plate of the present invention can not only realize the rapid and accurate identification of the automobile license plate by the intelligent transportation system, improve the accuracy and time efficiency of identification, and reduce the cost of manual identification; The adverse effects of ghost license plates; in addition, the present invention provides license plate QR two-dimensional code information interface for intelligent traffic management, and provides possibility for researching and developing related portable devices, and realizing intelligent, unified and portable traffic police law enforcement. broad.

The invention relates to a chaos image encryption method based on dual scrambling and DNA coding, firstly, carrying out bit plane decomposition on a plaintext image and carrying out DNA coding and transformation on the image to turn the image into a three-dimensional DNA matrix; then, scrambling the three-dimensional DNA matrix through the dual scrambling operation, wherein the sequence of the chaotic sequences is scrambled and the DNA sequence is scrambled in a bit level through combining the three-dimensional cat mapping; next, performing diffusion operation on the scrambled three-dimensional DNA matrix, and converting the diffused matrix into a two-dimensional DNA matrix; finally, performing decoding operation on the two-dimensional DNA matrix to obtain a ciphertext image. According tothe invention, the SHA256 hash function of the plaintext image is used to calculate the initial value of the chaotic system, and the parameters of three-dimensional cat mapping are also related to theplaintext image, which enhances the ability of the algorithm to resist the selection of plaintext attack. Experimental results and safety analysis show that the encryption scheme can resist various known attacks, and can effectively protect the security of images and also can improve the security level.

The invention discloses a hyperchaotic system based quantum image encryption method. The method comprises: finishing quantum image encryption by utilizing CNOT operation to realize XOR operation of a quantum image, namely, generating a hyperchaotic sequence by a Chen's hyperchaotic system, controlling unit transformation and NOT gate by a processed hyperchaotic sequence to construct CNOT transformation, and then, utilizing the CNOT operation to realize the XOR operation of the quantum image, thereby finishing the quantum image encryption. According to the method, the XOR operation of the quantum image is constructed for the first time and applied to the quantum image encryption, so that the attack resistance and security of an encryption algorithm can be enhanced; an initial condition of the Chen's hyperchaotic system serves as a secret key of the encryption algorithm, so that the effect of expanding secret key space is achieved; and the algorithm can resist strong attack, so that the secret key is easier to allocate, store and memorize.

The invention discloses a safe and effective client deduplication protocol based on proof of ownership, which belongs to the technical field of communication. The present invention includes: system initialization safety factor and parameter, client and key server communication obtain the key of encrypted file through blind signature, cloud server and client communication implementation challenge-response mechanism; Key server introduces Rate-limiting strategy, limits The number of times the client initiates requests to the key server within a certain period of time; the invention of this scheme resists exhaustive attacks and spoofing attacks, ensuring the security and efficiency of the proof-of-possession protocol; the invention can improve the efficiency of authentication and save storage space , guaranteeing a constant communication cost.

The invention provides an image encryption method based on H geometric fractal and a Hilbert curve. The image encryption method comprises the following steps: calculating a hash value of the originalgray level image as an initial value of a chaotic system by using an SHA-3 algorithm, and carrying out bitwise ratio specificity or diffusion on image pixels by using a sequence generated by the chaotic system; And alternately carrying out diffusion operation and two-dimensional Hilbert scanning curve scrambling operation by using the second-order H fractal to obtain an encrypted image. Accordingto the invention, Hilbert curve scanning scrambling and H geometric fractal diffusion are adopted, and a chaotic system, DNA coding, a Hilbert scanning curve and H fractal are combined to realize tworounds of pixel position scrambling and pixel value diffusion; Experimental results and security analysis show that the method not only has enough key space to resist exhaustive attacks, but also canresist statistical attacks, differential attacks, data loss attacks and noise attacks, and is widely applicable to secure transmission of image information.

The invention discloses a chaotic encryption method for voice information. The method is characterized in comprising the steps of 1), establishing a dynamic variable parameter composite chaotic system and generating a real-value chaotic sequence of which length is the same to that of a plaintext voice sequence through utilization of the system; 2), carrying out binarization processing on the real-value chaotic sequence, thereby obtaining a chaotic key sequence of which length is the same to that of the plaintext voice sequence; and 3), through combination of the chaotic key sequence, carrying out bit-by-bit exclusive or operation on the plaintext voice sequence, thereby obtaining a ciphertext. According to the method, under limited calculation precision, the chaotic sequence with good pseudo-randomness can be generated, the valid precision effect is reduced, and a chaotic sequence cycle is prolonged; and through adoption of a chaotic system cascading mode, the encryption security is improved, a sufficient key space can be generated, and an exhaustive attack can be resisted effectively.

The invention provides a method for constructing an IP core of an FPGA-based ZUC encryption system. ZUC is used as a key stream generation algorithm, and the output of an improved one-dimensional discrete chaotic system based on the Logistic chaotic system is used as the initial vector IV of ZUC, which is implemented in hardware. When encrypting the system, the flow management mode is used to realize the data interaction between various modules. In this transmission mode, both the upstream and downstream have the right to stop the other party and the obligation to respond to the other party being stopped. The transmission guarantees the correctness of the handshake logic and the continuity of the data. The FIFO memory is added to the corresponding module to cache, so that the upstream and downstream The latent period of inter-divergence can be converged to 1, so that the advantages of FPGA parallel work can be truly utilized, and the running speed of the entire encryption system can be effectively improved. The present invention combines the sequence cipher with chaos through the important parameter initial vector IV in the sequence cipher, so that the key of the whole system can be replaced regularly, thereby further improving the security performance of the whole system.