A method, apparatus and computer program product for secure communication includes receiving a message for transmission from a transmitting node to a receiving node. The message is split into a plurality of channels and each channel receives an identical copy of the message. Noise data is added to each version of the message. The noise data is different for a respective copy of the message than any other version of the message thus producing a plurality of ciphers each for a respective channel. The ciphers are transmitted via the respective channels from the transmitting node to the receiving node.

Disclosed is a method of encrypting a data signal for providing to an input of a radio frequency transmitter, such as modulated baseband signals in the physical layer for wireless transmission. The method comprises receiving the data signal comprising one or more first frequency components with a first phase profile in a frequency band of interest; applying a dispersive encrypting signal filter to the data signal to generate an encrypted data signal comprising the one or more frequency components with a second phase profile, wherein the second phase profile is different to the first phase profile. Decryption is achieved by applying a decrypting filter to the encrypted data signal to substantially reverse the effect of the encrypting filter and recover the first phase profile.

Systems, apparatuses, methods, and computer program products are disclosed for session authentication. An example method includes receiving, by decoding circuitry and over a quantum line, a set of qbits generated based on a first set of quantum bases. The example method further includes decoding, by the decoding circuitry and based on a second set of quantum bases, the set of qbits to generate a decoded set of bits comprising at least one wildcard bit. The example method further includes generating, by session authentication circuitry, a session key based on the decoded set of bits, wherein the session key is generated based at least in part on the at least one wildcard bit.

A key distribution method based on broadband physical random sources includes: utilizing a driving semiconductor laser to generate an optical signal, passing the optical signal through a phase modulator driven by a random signal and then equally dividing the phase-modulated optical signal into two identical paths, injecting the two identical paths into slave semiconductor lasers at both communication parties Alice and Bob's sides, respectively, to generate initial synchronized signals, using the generated initial synchronized signals as driving signals to phase-modulate optical signals generated by continuous-wave (CW) light sources, and inputting the modulated optical signals to dispersion modules; wherein after the modulated CW optical signals pass through the dispersion modules, two synchronized broadband noise-like random signals are generated, and then high-speed synchronized keys are generated by a post-processing method.

Disclosed is a method of encrypting a data signal for providing to an input of a radio frequency transmitter, such as modulated baseband signals in the physical layer for wireless transmission. The method comprises receiving the data signal comprising one or more first frequency components with a first phase profile in a frequency band of interest; applying a dispersive encrypting signal filter to the data signal to generate an encrypted data signal comprising the one or more frequency components with a second phase profile, wherein the second phase profile is different to the first phase profile. Decryption is achieved by applying a decrypting filter to the encrypted data signal to substantially reverse the effect of the encrypting filter and recover the first phase profile.

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.

In the field of image encryption and decryption, in order to solve the problem of small key space in the encryption process caused by low dimension of one-dimensional chaotic map and few initial values and control parameters, the present disclosure provides an image encryption and decryption communication algorithm based on two-dimensional lag complex Logistic map, which expands the variables of one-dimensional Logistic map from the real number domain to the complex number domain, improves the dimension of the mapping system, increases the number of keys, and expands the mapping range, wherein the new mapping system is more sensitive to small disturbances of initial values and parameters, which can break the strong correlation between pixels in the original image, so that the pixels of the encrypted image are uniformly distributed in the whole plane, and the features of the original image are hidden.

A digital communication method over an optical channel. Bob modulates a coherent optical signal with a random envelope phase φr, known to him and not to Alice, and transmits the modulated coherent optical signal (envelope) over the optical channel to Alice. Alice further modulates the envelope with a key phase φk, based on a secret key and a selected modulation scheme, to create a cipher envelope, and sends the cipher envelope towards Bob along the optical channel. Bob then demodulates a received version of the cipher envelope by removing the random envelope phase φr (known to Bob) and then measures the phase of the resulting demodulated coherent optical signal with the coherent detector to extract, to within a certain margin of error, the key phase φk, from which Alice's secret key can be decoded. Bob then uses the secret key for encrypting messages sent to Alice over any digital network.

A coherent detection-based high-speed chaotic secure transmission method includes: at a transmit terminal in a chaotic secure transmission system, optically coupling an optical chaotic carrier and transmission information by using an orthogonal basis to mask the transmission information by using a noise-like feature of the chaotic carrier, so as to obtain a chaotic masked signal; adding a fast phase disturbance and a fast polarization disturbance to the chaotic masked signal and transmitting the chaotic masked signal over an optical fiber transmission link; and at a receive terminal, obtaining the chaotic masked signal through coherent detection, compensating the chaotic masked signal for linear and nonlinear effects through digital signal processing, and using a polarization orthogonal basis- or phase orthogonal basis-based chaotic decryption algorithm to separate the chaotic carrier from the signal so as to complete decryption.

A device for generating a key has a multimode interferometer which can be coupled to a light source and has a light path having an electro-optical material, the light path being configured to obtain light at an input side, influence the light under the influence of a locally varying refraction index of the electro-optical material and provide influenced light at an output side. The device has a receiver configured to receive the influenced light at the output side, and has an evaluator configured to perform an evaluation based on the influenced light and to generate the key based on the evaluation.