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

The invention relates to a color image encryption method based on a chaos sequence and a hyper-chaos system. The color image encryption method mainly comprises the following steps: an original color image is subjected to bit level united scrambling to obtain a scrambled image; the scrambled image is decomposed into three primary color components, that is R, G and B, and the hyper-chaos system is used for generating an encryption matrix which is used for encrypting the scrambled image; all pixel values of the three primary color components of the scrambled image are changed by utilizing the encryption matrix in combination with plaintext information and information of the three primary color components, united diffusion is conducted to obtain the three primary color components of the image after the united diffusion, and therefore a final encrypted image is obtained. By means of the color image encryption method, a secret key space is greatly enlarged, the safety, the encryption effect and the sensitivity of a secret key are higher, the anti-attack ability is stronger, and hardware implementation is easier.

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 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 provides a diffusion mapping scrambling and chaotic system combined image encryption method, which is characterized by forming a diffusion matrix and an Arnold mapping matrix through a chaotic sequence generated by a two-dimensional nonlinear dynamical system constructed by a Logistic system; then, carrying out diffusion on a color image in primary colors, and carrying out scramblingon the color image on different bit planes; finally, carrying out encryption on a scrambled image file through a chaos sequence generated by a Chen system; and under the action of a key, generating achaos sequence through the Chen system and module operation, and carrying out multiple XOR operation to decrypt the encrypted image. The method adopts the Chen chaotic system and chaotic system combined encryption, has a very large key space and can resist key exhaustive attack; statistical distribution of the encrypted image is completely destroyed, and the method has a very good ability to resist statistical analysis; and the file encryption method can effectively resist attacks using pixel correlation analysis.

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 discloses a joint channel security coding method based on a balance index and a polarization code. The method comprises the steps that after polarization code coding is carried out on all message sequences, the sequences are encoded into balance code words with the same number of 0 and 1; the balance index is used to carry out one-time pad sequence password encryption with small complexity on the balance code words; and private key encryption system encryption is carried out on the balance index based on the polarization code. The code words have dual functions of error correction and encryption, which can reduce the overhead of a system. In the design of the private key encryption system, the redundant information freeze bit of the polarized code is used as one private key which has the tasks of error correction and encryption; a randomly generated error vector ensures that the system is resistant to the existing exhaustive attack and selection plaintext attack; and the decoding complexity is reduced.

The present invention discloses a light chaos-based color image encrypted transmission method and a system thereof. The system comprises a laser module, an image encryption module and an image decryption module. First, a laser generates chaos output under the action of light feedback, and an encrypted key is extracted from a generated chaos signal; a scrambling and diffusion encryption processing is performed on an original image through 3D cat mapping and Logistic chaos mapping and other methods; and an encrypted image is transmitted in an optical fiber by using a chaos concealment technology, and then the encrypted image is decrypted correspondingly, so as to recover the original image. The color image encrypted transmission method and the system thereof have high security and fast transmission speed.

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 belongs to the field of information security, and particularly relates to a transparent data integrity auditing and transparent encrypted data deduplication protocol based on a block chain. The scheme of the invention comprises four modules: parameter initialization, encryption key acquisition, bidirectional upheaval checking, transparent integrity auditing and transparent de-duplication. Compared with the prior art, the protocol can resist the bias audit and delay audit of the cloud server, and meanwhile, the situation that the cloud server claims an erroneous duplicate removal level to charge additional fees can be avoided. According to the protocol, single-point failure attacks and exhaustion attacks can be prevented, and bidirectional ownership proof of a user and a cloud server can be provided. The invention realizes a secure and effective protocol based on the block chain, and can simultaneously realize transparent data integrity auditing and transparent data de-duplication.

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 an image encryption and decryption method based on a fractional order translation chaotic system, and relates to the fields of computer cryptography, image encryption processing and communication and network engineering, which can solve the problems that initial conditions of an existing chaotic system are not associated with plaintexts, plaintext attacks cannot be resisted, and the safety is poor. According to themethod, translation transformation is conducted on the fractional order chaotic system by introducing a piecewise function, parameters are set, different numbers of scroll attractors can be generated, and the fractional order translation chaotic system perfects the field of fractional order chaotic systems composed of three-dimensional one-time autonomousconstant differential. Meanwhile, the fractional order multi-scroll chaotic system has higher dimension space and higher initial value sensitivity, the image encryption and decryption algorithm basedon the system is high in randomness and multiple in secret key parameters, a multi-iteration mode is adopted in the encryption process, an encrypted ciphertext matrix becomes very uniform, and therefore the purpose of effectively hiding original image information is achieved.

The invention discloses an automobile license plate with an encrypted QR two-dimensional code. The automobile license plate is characterized in that the obverse of an automobile license plate contains an encrypted QR two-dimensional code cipher text image and license plate number text. The automobile license plate can be identified quickly and accurately by an intelligent traffic system, meanwhile, the accuracy and time efficiency of identification are improved, and the cost of artificial identification is reduced; a quite strong anti-counterfeiting function is achieved by adopting the encrypted QR two-dimensional code, so the adverse effect of a counterfeit license plate is reduced; besides, a license plate QR two-dimensional code information interface is provided for intelligent traffic management through the automobile license plate, and the automobile license plate allows research and development of related portable devices and implementation of intelligentialization, normalization and lightening of traffic police enforcement to be possible, thereby having broad application prospects.

The invention provides a DNA one-time pad image encryption method based on multiple secret keys, and the method comprises the steps: obtaining four encryption parameters through the calculation of two-dimensional discrete cosine transform, two-dimensional inverse discrete cosine transform, two-dimensional discrete Fourier transform and two-dimensional inverse discrete Fourier transform according to a to-be-encrypted image; taking the four encryption parameters as initial values of four chaos respectively to generate four chaotic sequences; selecting a natural DNA sequence, and processing the four chaotic sequences by using the natural DNA sequence to obtain two diffusion matrixes and two scrambling matrixes; and alternately performing two rounds of diffusion operation and two rounds of scrambling operation on the to-be-encrypted image to obtain an encrypted image. According to the invention, the initial values of all chaotic functions are obtained by calculating the original image information, so that the differential attack can be well resisted. Meanwhile, the problem that one-time pad messy codebooks are difficult to store is solved by utilizing massive DNA sequences, the one-time pad encryption effect is achieved, and the security of the encryption method is improved to a great extent.

The invention provides a user password encryption method based on an improved MD5 encryption algorithm, and relates to the technical field of information security. The method comprises the following steps: firstly, encrypting a password input by a user during registration through an MD5 algorithm to obtain the initial encrypted data, generating a random number through an elliptic curve, sending the random number to a pseudo-random number generator, generating a random character string by the elliptic curve and the pseudo-random number generator, performing bitwise exclusive OR on the random character string and the encrypted data generated by an MD5 algorithm to generate new encrypted data as a message abstract, and storing the new encrypted data in a database. And when the user logs in again, the input password is encrypted, and the encrypted ciphertext is compared with the ciphertext stored in the database for verification. According to the method, based on the improved MD5 encryption algorithm, the random character string is added after the original MD5 algorithm is operated to perform exclusive OR operation, so that the randomness and the collision resistance of the algorithm are improved, the security of the algorithm is improved, and exhaustion attack, birthday attack and differential attack can be effectively resisted.