Image encryption and decryption methods based on biological information. The encryption method includes: obtaining the biological information; using the chaotic mapping method to preprocess the biological information to construct the first chaotic biological phase plate and the second chaotic biological phase plate; obtaining the original image to be encrypted and use the first chaotic biological phase plate and the second chaotic biological phase plate to determine the reconstructed optical encrypted image based on the discrete cosine transform method, and Fresnel transform method; and inputting reference light that interferes with the encrypted image of the reproduction light to determine the encrypted image. The invention can reduce the information amount of the key, improve the efficiency of storage and transmission, and improve security.

A system may include a first conductive plate configured at least to receive an input signal and a second conductive plate configured at least to output an output signal. The system may further include a first memristor material positioned between the first conductive plate and the second conductive plate. The system may further include a second memristor material positioned between the first conductive plate and the second conductive plate. The first memristor material and the second memristor material may be in parallel electrically. The first memristor material may be different from the second memristor material.

A criterion method of GCCS (Globally Complete Chaos Synchronization) for three-node VCSEL (Vertical Cavity Surface Emitting Laser) networks with delay coupling is provided, including steps of: providing a delay-coupled VCSEL network consisting of three identical units and dynamic equations of the VCSEL network; providing assumptions of an outer-coupling matrix and a unitary matrix under the dynamic equations of the VCSEL network; in the three-node VCSEL network, determining rate equations of i-VCSEL, determining dynamic equations of a synchronization manifold, and determining a master-stability equation; calculating three maximum Lyapunov exponents; determining a stability of a synchronization state of the three-node VCSEL network, and determining whether the synchronization manifold of the VCSEL network is a chaotic waveform. Through a master-stability function, the method for determining whether the GCCS is achieved among all node lasers is provided, which solves a difficult problem of GCCS criterion for the VCSEL networks.

A system includes first and second sets of communication devices. A processor coupled to the first set of communication devices produces a first encoded vector and transmits the first encoded vector to the second set of communication devices via a communication channel that applies a channel transformation to the first encoded vector during transmission. A processor coupled to the second set of communication devices receives the transformed signal, detects an effective channel thereof, and identifies left and right singular vectors of the effective channel. A precoding matrix is selected from a codebook of unitary matrices based on a message, and a second encoded vector is produced based on a second known vector, the precoding matrix, a complex conjugate of the left singular vectors, and the right singular vectors. The second encoded vector is sent to the first set of communication devices for identification of the message.

According to the chaotic communication method and system based on complex modified projective difference function synchronization provided in the present invention, when a chaotic signal has a relatively small amplitude, the amplitude of the chaotic signal can be adjusted by adjusting a proportional matrix, so as to mask plaintext better. Moreover, a robust controller is designed according to a filtered signal and a second coupling function, to ensure complex modified projective difference function synchronization, and such synchronization allows the bit error rate to be zero theoretically. In addition, complex modified projective difference function synchronization does not require a transmitter and a receiver to be exactly consistent, provided that the synchronization can be implemented under the effect of the controller, thereby solving the disadvantage in the prior art that the receiver system and transmitter system are required to have exactly identical structures, and simplifying a structure requirement on the communication system.

Continuous variable quantum secret sharing (CV-QSS) technologies are described that use laser sources and homodyne detectors. Here, a Gaussian-modulated coherent state (GMCS) prepared by one device passes through secure stations of other devices sequentially on its way to a trusted device, and each of the other devices coherently adds a locally prepared, independent GMCS to the group of propagating GMCSs. Finally, the trusted device measures both the amplitude and the phase quadratures of the received group of coherent GMCSs using double homodyne detectors. The trusted device suitably uses the measurement results to establish a secure key for encoding secret messages to be broadcast to the other devices. The devices cooperatively estimate, based on signals corresponding to their respective Gaussian modulations, the trusted device's secure key, so that the cooperative devices can decode the broadcast secret messages with the secure key.

Aspects of the current subject matter are directed to performing privacy-preserving analytics over sensitive data without sharing plaintext data. According to an aspect, a system includes at least one data processor and at least one memory storing instructions which, when executed by the at least one data processor, result in operations including: receiving, from each of a plurality of clients, a utility score and a partial noise value; performing, based on the received utility scores and the partial noise values, a secure multi-party computation of a privacy-preserving statistic, the performing of the secure multi-party computation of the privacy-preserving statistic further comprising determining a noisy utility score for each data value in a domain of output values and selecting a highest noise utility score from the determined noisy utilities scores; and providing, based on the selected highest utility score, an output value for the privacy-preserving statistic.

Memristor based chaotic oscillators exhibit complex dynamics. They are often chosen for secure communication owing to their interesting feature. In chaos-based secure communication applications using the master-slave configuration, synchronization is a central issue. Most of the synchronization methods proposed in the literature are asymptotic. In practice, it is desirable that synchronization be established in a predefined time. This invention provides new developments in the design of high-gain observers with an unknown input dedicated for predefined-time synchronization of memristor based chaotic systems. The proposed predefined-time extended high gain observer is constructed on the basis of a time-dependent coordinates transformation based on modulating functions that annihilate the effect of initial conditions on the synchronization time. Both noise-free channel and noisy channel are considered. Simulations performed on a numerical example illustrated the efficiency of proposed approaches.

Image encryption in which excessive concealment of information is prevented while reduction in cost is achieved by eliminating a need for a receiving side of an image to take measures against leakage of personal information is realized. In one example, a sensor device includes an array sensor with pixels having a light receiving element of visible or invisible light. A detector detects a target area on the basis of an image signal obtained by the array sensor. The target area in the image signal is encrypted on the basis of information from the detector. Thus, encryption of the image signal can be performed in the image sensor at least to the extent that no individual can be identified. Also, depending on a decryption key on a receiving side of the image, a part of the content of the image can be visually recognized while personal information is concealed.

A method making modifications during a key phase of physical layer security methods and enabling the physical layer security methods to be applicable in a wireless communication is provided. The method includes a step of generating a K common key, including steps to be carried out at a modulator during a data transmission phase.