177results about How to "Strong resistance to attack" patented technology

The invention provides a space network cross-domain anonymous identity authentication method based on hyper-chaos encryption, relates to the technology of space information network, and solves the problem that the security mechanism applied in the conventional network cannot be directly applied to space network, and space cross-domain identity authentication cannot be realized. Provided is a space network cross-domain anonymous identity authentication method based on hyper-chaos encryption. The method includes two parts: a register stage and an authentication stage, a chaos algorithm is sensitive to initial conditions and control parameters, the structure is complex, prediction and analysis are difficult, and pseudo random sequences with good randomness and complexity are provided so that the chaos is applicable to encryption. A quantum cellular neural network is a cellular neural network structure coupling via quantum cellular neural network automata, complex linear dynamic features are obtained from the polarizability and quantum phase of each quantum cellular automaton, a nano-scale hyper-chaos oscillator can be constructed, the power consumption is low, the integration level is high, and the application requirement of space network satellite nodes can be better met.

The invention provides a color image encryption method based on three-dimensional Logistic mapping and generalized Cat mapping, which comprises the following steps: reading an original color image toobtain two-dimensional pixel matrixes corresponding to R, G and B components, and straightening the two-dimensional pixel matrixes to obtain three pixel sequences; three groups of chaotic sequences are generated through three-dimensional Logistic mapping iteration, and subjecting the three groups of chaotic sequences and the three pixel sequences to XOR operation to realize diffusion processing; carrying out data reconstruction on the chaotic sequence obtained after diffusion processing and expanding the chaotic sequence into a three-dimensional cube; performing position scrambling processingon the three-dimensional cube through generalized Cat mapping; and converting the three-dimensional cube with the scrambled position into a cuboid which is a ciphertext image. According to the method,parameters and initial values of three-dimensional Logistic mapping and generalized Cat mapping and the plaintext image size are used as keys, the key space is increased. Encryption safety is improved, and the method has the advantages of being high in key sensitivity, high in anti-attack capability and the like.

The invention provides a digital watermark encryption realization method. On the basis of the research of a digital watermark embedding algorithm in a wavelet domain, the chaos theory is introduced into the establishment of the digital watermark; the algorithm that a chaos sequence which is generated by Logistic mapping is embedded into a wavelet domain digital watermark is proposed and realized; and the algorithm has the characteristics of secret key uniqueness, irreversibility, invisibility and robustness according to the specific unpredictability of the chaos sequence. An experiment proves that the algorithm has a good visual effect and is a practical and feasible digital watermark encryption algorithm.

The invention discloses a DDoS attack joint defense system and method based on blockchain, belongs to the technical field of DDoS attack defense, and aims to solve the technical problem of how to defend DDoS attacks safely, quickly and effectively. The system comprises at least one terminal device; at least one piece of edge equipment which is provided with an Ethereum client; a blockchain which is provided with a device information sharing smart contract and a device filtering smart contract, wherein the blockchain is used for realizing information sharing among the edge nodes based on a blockchain consensus mechanism, and the edge equipment is used for carrying out DDoS anomaly detection to obtain DDoS anomaly traffic information, storing the DDoS anomaly traffic information through local data, and uploading the DDoS anomaly traffic information to the blockchain based on the device information sharing smart contract.

The invention relates to the technical field of information security, and discloses an optical image encryption method based on a quantum cell nerve network hyperchaotic system, for solving the defect of insufficient non-linear degree of a conventional optical encryption system. According to the invention, an optical image is encrypted and decrypted by use of the quantum cell nerve network hyperchaotic system, due to the hyperchaonic characteristic of a quantum cell nerve network, the linearity characteristic of a conventional double-random phase coding optical encryption technology is made up for, and the optical image encryption method has the security characteristics of large secret key space and high anti-attack capability. Besides, since a quantum dot and a quantum cell automatic machine are novel nanometer-level electronic devices which transmit information through coulomb interaction, compared to the prior art, the quantum cell automatic machine has the advantages of super-high integration, super-low power consumption, lead-free integration and the like.

The invention provides a robust hidden watermark embedding and extracting method for 3D high definition digital videos, and belongs to the crossing field of image processing, etc. A user inputs a segment of 3D video, and an algorithm divides the 3D video into sequence frames according to a frame rate thereof and carries out an embedding operation on each frame in the sequence frames. On each frame, the algorithm separately carries out DCT conversion on left and right views with 8 * 8 pixel blocks a unit at first. Each bit in a watermark is sequentially embedded on a pair of 8 * 8 DCT coefficient blocks at the same positions in the left and right channel views. A watermark algorithm selects intermediate frequency areas in the DCT coefficient blocks for embedding and introduces three coefficient limit mechanisms to effectively limit the embedding strength, which are respectively a least identifiable difference perception model, a fine grain modulation parameter and an embedding reference matrix. According to the robust hidden watermark embedding and extracting method provided by the invention, the overall complexity is simplified on the theoretical foundation of the study of the watermarking technology based on single channel video, intensive tasks can be processed and calculated in parallel, the processing speed of the high definition 3D videos is accelerated, and the imperceptibility and the robustness are guaranteed on the premise of achieving the above effects.