Disclosed are an encryption and decryption method and device based on bit permutation and bit transformation. The method includes: configuring a memory space, and preparing corresponding storage spaces for a plaintext file, a ciphertext file and a key file; changing a bit value of an initial key stream according to a bit operation rule, so as to obtain a bit-transformed key stream, changing a bit value of a plaintext according to the bit operation rule depending on the key stream; on the basis of a bit-transformed plaintext stream, according to a bit permutation rule depending on the key stream, performing a bit permutation operation on the bit-transformed plaintext stream, and randomly distributing the plaintext stream in a ciphertext stream, so as to obtain a target ciphertext and store the same as a file.

The present invention discloses an image encryption method based on an improved class boosting scheme, which comprises the following steps: acquiring parameters of a hyperchaotic system according to plaintext image information; generating weights required by class perceptron networks through the plain text image information; bringing the parameters into the hyperchaotic system to obtain chaotic sequences, and shuffling the chaotic sequences by a shuffling algorithm; pre-processing the chaotic sequences after shuffling to obtain a sequence required by encryption: and bringing a plaintext image and the sequence into an improved class boosting scheme to obtain a ciphertext image, wherein the improved class boosting scheme is realized based on the class perception networks. The method solves the problems that update and prediction functions in an original boosting network are too simple and easy to predict or the like, so as to obtain the ciphertext image with higher information entropy.

Systems and methods performed for generating authentication information for an image using optical computing are provided. When a user takes a photo of an object, an optical authentication system receives light reflected and/or emitted from the object. The system also receives a random key from an authentication server. The system converts the received light to plenoptic data and uploads it to the authentication server. In addition, the system generates an optical hash of the received light using the random key, converts the generated optical hash to a digital optical hash, and uploads the digital optical hash to the authentication server. When the authentication server receives the upload, it verifies whether the time of the upload is within a certain threshold time from the sending of the random key and whether the digital optical hash was generated from the same light as the plenoptic data.

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.

Technologies are provided for clockless physically unclonable functions (PUFs) in reconfigurable devices. Embodiments of the disclosed technologies include processing circuitry configured to perform numerous operations. The operations can include receiving a challenge continuous pulse signal, and generating a response continuous pulse signal by iteratively extending the challenge continuous pulse signal in time-domain. In some configurations, the iteratively extending includes generating a next continuous pulse signal by operating on a prior continuous pulse signal according to a stretching function, and generating a second next continuous pulse width signal by operating on the next continuous pulse signal according to a folding function.

Systems and methods for azimuthal multiplexing using three-dimensional diffractive optics An azimuthal optical multiplexing system includes a light source. The system includes two or more at least partially transparent plates. Each plate of the two or more plates has a structured or patterned surface positioned in an optical path of the light source. The system includes means for rotating at least one plate of the two or more plates axially with respect to at least one other plate of the two or more plates. The means for rotating is operatively coupled to the at least one plate. The structured or patterned surface is configured to modulate light directed along the optical path and through the two or more plates.

A transmitter for a chaos communications system employing chaotic symbol modulation that perform auto-indexing, temporal gain control, increased path diversity and sequence lock up prevention. The transmitter includes a symbol mapper that converts a series of information bits to a series of bit symbols, and a chaos modulator providing chaotic spreading modulation of the bit symbols. The chaos modulator includes a plurality of chaos generators, one for each bit symbol, providing a chaos sequence for the bit symbols. Each chaos modulator includes a RAM/ROM that provides auto-indexing where a chaos sequence output from the RAM/ROM is fed back to an input of the RAM/ROM from which a chaos sequence at a next address in the RAM/ROM is selected as the output of the modulator.

A transmitter for a chaos communications system employing chaotic symbol modulation that perform auto-indexing, temporal gain control, increased path diversity and sequence lock up prevention. The transmitter includes a symbol mapper that converts a series of information bits to a series of bit symbols, and a chaos modulator providing chaotic spreading modulation of the bit symbols. The chaos modulator includes a plurality of chaos generators, one for each bit symbol, providing a chaos sequence for the bit symbols. Each chaos modulator includes a RAM/ROM that provides auto-indexing where a chaos sequence output from the RAM/ROM is fed back to an input of the RAM/ROM from which a chaos sequence at a next address in the RAM/ROM is selected as the output of the modulator.

A method for communicating magnetic resonance imaging (MRI) information wirelessly includes detecting an MRI system emission sequence, and identifying at least one parameter of the sequence. The at least one parameter identified is cross-correlated. A first initial condition for a first chaotic coded sequence and a second initial condition for a second chaotic coded sequence are determined based on the at least one parameter. The method further includes obtaining, from a modulation symbol mapped to MRI information generated at a local coil responsive to the sequence, a real component of the symbol and an imaginary component of the symbol. The real component of the symbol is encrypted based on the first initial condition, and the imaginary component of the symbol is encrypted based on the second initial condition. The encrypted real component and imaginary component of the symbol are wirelessly transmitted.

A key generation method includes modulating a first key to a first light source signal, to obtain a modulated optical signal, splitting the modulated optical signal, to obtain a first sub modulated optical signal and a second sub modulated optical signal, attenuating the first sub modulated optical signal such that a quantity of photons included in each period of the first sub modulated optical signal is less than a preset value, and sending an attenuated first sub modulated optical signal to a receive-end device, and obtaining a second key carried in the second sub modulated optical signal, and storing the second key.