184 results about "Key space" patented technology

The invention discloses a color image encryption and decryption method based on multiple-fractional-order chaotic systems. An encryption algorithm comprises an original image scrambling stage and a scrambling image encryption stage. Firstly, two different fractional-order chaotic systems are utilize to generate three scrambling arrays and respectively process R, G and B three primary color component arrays of an original color image I0 in a scrambling mode to obtain scrambled image I1. Furthermore, another two different fractional-order chaotic systems are utilize to generate three secret key arrays and carries out exclusive OR operation on elements on the secret key arrays and pixel of the scrambled image I1 one by one to change values of all pixel points of the scrambled image I1 to obtain encrypted image I2, and the image decryption is a reversed process of the encryption. The method uses the multiple-fractional-order chaotic systems so as to greatly enhance safety. Furthermore, the algorithm secret keys are large in space, high in secret key sensitiveness and strong in impact resistance.

The invention provides an image encryption method based on chaotic mapping and bit-level replacement. The method comprises the following steps: converting a grayscale image into an image matrix; iterating 2D-LSCM mapping to generate a chaotic sequence and mapping the chaotic sequence into a matrix, and returning a position index to perform pixel position exchange on the image matrix after descending sorting of each row; sequentially exchanging the lowest three bits in every two pixel bits to obtain an information fusion sequence of the image; performing iteration on the Logistic mapping to generate a chaotic sequence, and performing operation on the information fusion sequence and the chaotic sequence to obtain a pixel replacement column of the image; and performing pixel diffusion on thepixel replacement sequence of the image by using a chaotic sequence and a ciphertext diffusion technology to obtain an encrypted image. The chaotic mapping and scrambled images are used for replacement operation, the differential attack resistance is enhanced through bit information fusion operation and an image pixel-based diffusion method, the secret key space is large enough, violent attack canbe better resisted, and good safety is achieved.

The invention provides an image encryption method based on a multi-dimensional chaotic system and Josephf scrambling, and the method comprises the steps: carrying out the initialization of PWLCM mapping and 2D-LSCM mapping, and obtaining a sequence X, a sequence Y and a sequence Z; uniformly dividing the original image into sub-matrixes according to indexes, carrying out Gray curve scrambling on pixels in the sub-matrixes, and carrying out sequential recombination to obtain a recombined image matrix; taking out elements in the sequence X as a crossover operator, and performing bit crossover operation on the recombined image matrix to obtain an image matrix; taking out a pseudo-random value in the sequence Y as the step value of fixed-step Josephh scrambling, and performing Josephh scrambling operation on the image matrix to obtain a matrix; and taking out the pseudo-random value in the sequence Z and the element pixel value in the matrix to carry out XOR ciphertext feedback to obtain afinal encrypted image. The method can effectively encrypt the image, has a large key space, has high sensitivity to the to-be-encrypted image and the initial key, and has good defense capability whenresisting various attack modes.

In certain embodiments, probabilistic secondary token issuance on a blockchain may be facilitated based on a burning of a primary token of the blockchain. In some embodiments, a blockchain transaction associated with a user may be obtained. The blockchain transaction may indicate (i) an amount of a primary token of the blockchain (owned by the user) to be burned and (ii) a secondary token of the blockchain. Based on the blockchain transaction, (i) the amount of the primary token may be burned, and (ii) a portion of a key space may be allocated to the user. Based on a determination that a hash of at least a portion of a first block of the blockchain corresponds to the key space portion allocated to the user, an issuance of an amount of the secondary token to the user may be stored on a second block for the blockchain.

The invention belongs to the field of information security and relates to construction of encryption algorithm. The password (encryption) algorithm is uncertain and random by using the random function to construct the block encryption method. The uncertainties are determined by partial data in the secret key and some information of plaintext. The encryption method has the advantage that the indeterminacy of the algorithm ensures that the password analysis becomes very difficult as a result of the lack of the information about the algorithm, so that a great amount of known (selected) plaintext ciphertext pair of the same algorithm and the same secret key cannot be acquired, and the condition for password analysis is destroyed to enhance the security. The existing abundant password analysis aims at determined algorithm, and the password analysis is difficult to perform when the algorithm is random. The uncertainty of the password system is increased through multiple ways. The encryption algorithm of the plaintext is uncertain, and the algorithms of different blocks are different, therefore, the secret key space can be increased so as to enhance the safety.

The invention provides a method for encrypting MPEG (moving picture experts group) video streaming information based on a hyper-chaotic sequence, which is characterized in that a streaming encryption technology is combined with a block encryption technology so as to encrypt I frames and P frames of MPEG video streaming; in an algorithm, an initial value of a four-dimensional hyper-chaotic system is taken as an external secret key, the hyper-chaotic sequence generated by the four-dimensional hyper-chaotic system is utilized, and AC (alternating current) coefficients of video images are utilized to generate an inner secret key; and an XOR operation is carried out on DC (direct current) and AC coefficients of the I frames respectively, position scrambling is carried out on luminance information of the I frames by taking a 8*8 block as a unit, the XOR operation is carried out on motion vectors of F macro blocks in the P frames, and original video information is disturbed sufficiently. In the method, the space of the secret keys is huge, and the capacity to resist brute force attacks is strong; because an encryption process is embedded into an MPEG coding process, the method is good in instantaneity; and due to the introduction of the inner secrete key, the capacity of the encryption algorithm to resist plain text attacks is strengthened.

The invention discloses an image encryption method based on L-F cascade chaos and 3D bit scrambling. Image encryption is mainly divided into two steps: (1) 3D bit scrambling encryption and (2) diffusion operation. A novel L-F cascade chaos is constructed, the problem that a blank window exists due to uneven distribution of Logistic is solved while the rapidity of the Logistic is guaranteed, the chaos interval and number of parameters are increased, the secret key space is increased, and the exhaustion attack resistance of the system is improved. According to the method, the randomness of scrambled ciphertext is improved by adopting a 3D cyclic shift bit scrambling mode, and the problem that a bit scrambling sequence is insensitive is solved. According to the method, high-order informationcontaining a large amount of plaintext information and low-order information containing a small amount of plaintext information are separately scrambled, so that the noise attack resistance of the system is improved. According to the encryption system, the plaintext SHA-256 is used for carrying out strong association on the chaotic key, so that the plaintext sensitivity and the capability of resisting the attack of the selected plaintext are effectively improved.

The invention relate to a wireless sensor network key pre-distribution method, which comprises the following steps: step S001: disposition server generating R upper triangular matrixes G and R diagonal matrixes D at random on the finite field GF (q); step S002: generating R groups of real symmetric matrixes K; step S003: saving the ID of every node, row vector seed gir, column vector; step S004: starting base station, and clustering networking; step S005: discovering the shared secret key pair corresponding to secret key space between nodes by pre-distributing secret key; step S006: distributing cluster secret keys with cluster head towards inner-cluster by the constructed shared secret key pair between nodes; step S007: expanding the secret key space dimension. The invention achieves lower node capacity, communication complexity and calculation complexity while ensuring the network completely is communicated; and has higher node anti-capture capability.

A multi-image encryption method based on fractional fourier domain phase template multiplexing comprises the steps of pure phase extraction, phase modulation and fractional fourier transform. The method applies a fractional fourier domain phase recovery procedure to multi-image encryption, increases a convergence rate of an encryption system, avoids crosstalk noise influence, enlarges a key space, and solves the problems of low convergence rate, crosstalk noise presence and small key space of the existing encryption method, an encryption procedure and a decryption procedure can be realized by an optical method, a system is simple, and the method is convenient to operate.

The invention discloses an intelligent optimization four-dimensional chaotic vector encryption orthogonal transmission method. The invention belongs to the technical field of information transmission,the method is based on an orthogonal mode division multiplexing transmission system. A communication system is encrypted from four dimensions of communication constellation, OFDM subcarrier frequency, the time and the mode; enough key space can be provided by multi-dimensional hyper-chaotic encryption to provide powerful guarantee for communication security, innovatively utilize machine learningto multi-dimensional encryption optimization, and realize coordination optimization between dimensions, thereby effectively reducing the time of an encryption processing process, and reducing the negative efficiency of the communication system with encryption steps in the digital signal processing module. Compared with a traditional encryption transmission scheme, the scheme provided by the invention has more powerful security guarantee, and the encryption cost is lower.

The invention discloses a color image encryption and decryption method and system based on double chaotic cross-diffusion. First, the parameters of Logistic and ChebyShev iterations are randomly generated, and then the initial key required for Logistic and ChebyShev iterations is input, and the transient state is eliminated by multiple iterations. Afterwards, Logistic and ChebyShev are used to iterate three times, and the results of the iterations are used as the initial keys for encryption, thereby actually increasing the key space. Then take the pixel in the picture, if the value corresponding to the pixel position is an odd number, use ChebyShev iteration to get the encryption key, otherwise use Logistic iteration to get the encryption key, so as to reduce the correlation between adjacent pixels. Then use the three channels of R, G, and B of this pixel to perform XOR operation with the R', G', and B' of the previous encrypted pixel to diffuse. The present invention reduces the number of iterations on the premise of ensuring safety, can reduce encryption time, and improves efficiency, and is especially suitable for image encryption of mobile devices such as mobile phones and tablet computers that require high real-time performance.

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 Lorenz chaotic pseudo-random sequence generator based on an m sequence. The generator comprises an initial value selection module, a Lorenz chaotic iteration module, a quantification module and an m sequence disturbance module, wherein the initial value selection module is used for giving an initial value needed by a Lorenz chaotic equation before Lorenz chaotic iterationis started and giving an output value generated in last iteration to next iteration to serve as an initial value; the Lorenz chaotic iteration module realizes operation of the Lorenz chaotic equationthrough floating point fractional arithmetic and generates a chaotic real value sequence; the quantification module converts the chaotic real value sequence into a pseudo-random sequence through a bit sequence design method; and the m sequence disturbance module generates the m sequence through a linear feedback shift register and uses the m sequence to disturb the chaotic real value sequence, the disturbed chaotic real value sequence is returned to the initial value selection module, and next iterative operation is performed. The generator overcomes the defect of randomness of an existing pseudo-random sequence, and the generator has a large key space, can resist an exhaustive attack and meets the requirements of various application occasions.

The invention provides an image encryption method and device, electronic equipment and a readable storage medium. The method comprises following steps of acquiring a first pseudo-random sequence and asecond pseudo-random sequence with preset lengths by connecting a hybrid chaotic system in parallel in a precision limited mode; processing the first pseudo-random sequence with the preset length toobtain a first permutation matrix and a first diffusion matrix; according to the first permutation matrix, replacing the to-be-encrypted image by a square formed by four adjacent pixel points as a unit to obtain a first image after replacement; and performing row diffusion and column diffusion on the replaced first image according to a first diffusion matrix to obtain an intermediate result image,and performing a second round of replacement and diffusion on the intermediate result image through the same method to obtain an encrypted image. With the method, the secret key space is increased, the operation speed is increased, higher safety is achieved, and the calculated amount during replacement and diffusion can be reduced.

The invention provides a power battery traceability management code encryption method based on an improved AES algorithm. The power battery traceability management code encryption method comprises thefollowing steps: step 1, grouping plaintext information; step 2, generating an initial key by using a two-dimensional composite chaotic sequence, and performing AES algorithm improved encryption; step 3, carrying out Base64 secondary encryption; step 4, carrying out QR coding; step 5, conducting a decryption process. According to the invention, a two-dimensional composite chaotic sequence is combined with a traditional AES encryption algorithm, and an improved AES encryption algorithm is provided. One group initial key correspondingly encrypts one piece of QR code plaintext information, the security problems of fixed initial secret keys, mutual derivation among the secret keys and secret key space determination in a traditional AES encryption algorithm are effectively eliminated, the decryption difficulty is increased, the confidentiality and privacy of the QR code information are greatly improved, the information of a power battery is effectively protected, data sharing among power battery maintenance, fault analysis, equipment accessories and battery storage is achieved, and scientific and refined management is achieved.

The invention relates to a watermark encryption and decryption algorithm based on a chaotic neural network, and belongs to the technical field of information hiding. The characteristic that Logistic chaotic mapping is extremely sensitive to an initial value and the good approximation effect of the Chebyshev neural network are utilized, and an LCNN network is established to encrypt the watermark, so that the security of the watermark is ensured. The network weights obtained by the LCNN neural network during each operation are different, and the secret keys for watermark encryption are also different, so that the encryption algorithm obtained based on the LCNN has a large secret key space, and the security is high. Besides, when the chaos initial value is slightly changed, the secret key isgreatly changed, the encrypted watermarks obtained after encryption are different from one another, the expected goal of one-time pad can be achieved, and the safety of the algorithm is improved.

The invention provides an image encryption method based on finite time synchronization of a fractional order driving response system. The method comprises the steps of reading a three-dimensional color image to obtain a color component matrix; obtaining chaos signals based on a fractional order driving system, and carrying out resampling to obtain a discrete chaos sequence; arranging and recombining the discrete chaotic sequence according to a column mode to obtain a two-dimensional array, and normalizing the two-dimensional array to obtain a pseudo-random matrix; performing binary XOR operation on the color component matrix by using a pseudo-random matrix to obtain a color component matrix encrypted for the first time; performing scrambling operation on the color component matrix encrypted for the first time and a pseudo-random matrix to obtain a color component matrix encrypted for the second time; and performing equal-area mapping scrambling on the color component matrix encrypted for the second time to obtain a final encrypted image color component matrix. The method has the advantages of large key space, high sensitivity and high attack resistance, and can effectively ensure the security and confidentiality of the encrypted image.

The invention relates to a key management system and method for federated learning security audit, and a storage medium. The key management system comprises: a user interface module used for receiving a request of a user; a key service processing module which is configured to generate a visible key space specific to the user, wherein a key in the visible key space specific to the user can be used for responding to a request of the user; a key generation module; and a key storage module. The state of each secret key stored by the secret key storage module is determined according to whether the federated learning task corresponding to the secret key is finished or not and whether the security audit requirement corresponding to the federated learning task is met or not. The method not only can meet the requirements of various federated learning frameworks and software products for normalization and security, but also considers the requirements of subsequent security auditing and the differences of different individuals of the same participant or different participants in the aspects of permission, privacy, isolation requirements and the like.

The invention discloses an image encryption method based on a chaotic adaptive mechanism. According to the method, the key management difficulty in one-time pad encryption scheme (keys for encryptingdifferent plaintexts are different) is overcome, and a chosen plaintext attack also can be resisted. Compared with the conventional encryption scheme, the encryption method has the advantages that random sequences employed in an encryption process are obtained by adding disturbance items associated with the plaintexts to chaotic sequences rather than an initial value of a chaotic system, and the disturbance items are not part of the keys. A legal decryptor decrypts ciphertexts in a diffusion phase and obtains the disturbance items associated with the plaintexts according to obtained scrambledciphertexts. An experimental result and security analysis show that the algorithm has the advantages that the key space is great, the ciphertexts are very sensitive to the plaintexts and the keys, thepixel distribution of the encrypted images is uniform, the correlation of the adjacent pixels of the ciphertexts is very low, information entropies of the ciphertext images are approximate to 8bit, and the chosen plaintext (ciphertext) attack is resisted. The method has a good application prospect.

The invention discloses a method, system and device for optimally executing an expected timed task and a storage medium, and the method comprises the steps: responding to a received asynchronous task, and judging whether the asynchronous task is the expected timed task or not; in response to the asynchronous task being an expected timed task, judging whether a first difference value between an execution moment of the expected timed task and a current moment exceeds preset time or not; in response to the situation that a first difference value between the execution moment of the expected timed task and the current moment exceeds the preset time, storing the ID and parameter information of the expected timed task into Redis, and setting a key as an exclusive mark of the expected timed task; and calculating a second difference value between the first difference value and the preset time, and setting the timeout time of the key as a third difference value between the second difference value and a preset value. According to the method, on the basis of a release and subscription mode of a key space message of Redis, an asynchronous task calling module is redefined, and an expected timed task execution module of Celery is optimized.

The invention relates to a color image block encryption algorithm based on a hyper-chaotic system and a DNA sequence. The color image block encryption algorithm utilizing the hyper-chaotic system andthe DNA sequence has the advantages that an initial value when a random matrix is generated comes from a hash value of a plaintext image, and one-time pad is realized. Meanwhile, the encrypted image is not the whole image any more, but is consist of image blocks. The DNA coding mode of each sub-block and the DNA operation among the sub-blocks are pseudo-random and are dynamically determined by a chaotic system. Thus, one plaintext image comprises multiple encoding modes and operation modes, the key space is larger, the encryption effect is better, and the security is higher. The simulation result is that the encrypted histogram is uniformly distributed; wherein the key space is at least 1080; the information entropy after encryption is 7.999; in sensitivity analysis, NPCR is 99.6012%, UACIis 33.5786%, and the sensitivity analysis result is close to an ideal state. Accordingly, various attacks may be resisted.

The invention discloses a polarization, phase and mode dynamic disturbance method, which belongs to the technical field of communication. Based on combination of a Chua's multi-scroll chaotic system and a Logistic chaotic system, different scrambling parameters are adopted to respectively carry out scrambling encryption on polarization, phase and mode in the communication system, and a decryptionsequence is generated by using a scrambling vector at a receiving end to decrypt; due to the independent operability of attraction factors and subcarriers of the Chua's multi-scroll system, the communication system can obtain a large security key space; the method has good anti-illegal reception performance, greatly improves the safety of user communication, and points out a potential road for thedevelopment of optical multicarrier in the future.