A method, for preventing the intelligible voice recording is provided. The voice of a subject or interlocutor is recorded for a given time interval thereby providing a voice recording. The voice recording is cut into shorter time interval segments thereby providing a set of voice recording segments. The set of voice recording segments is mixed in a randomly rearranged order. The mixed set of voice recording segments is spliced into a single randomly mixed voice recording. Emitting the randomly mixed voice recording during speaking of the subject or interlocutor prevents the intelligible recording of the voice of the subject or interlocutor.

Systems, devices, methods, and instructions for transmitting a signal by an electronic apparatus that include generating transmission data and pseudo-random data corresponding to the transmission data, setting a first pseudo time delay interval for the transmission data and a second pseudo time delay interval for the pseudo-random data, acquiring a data signal for transmitting the transmission data to correspond to the first pseudo time delay interval and a pseudo-random signal for transmitting the pseudo-random data to correspond to the second pseudo time delay interval, and transmitting an overlapping signal including the data signal and the pseudo-random signal.

Systems, devices, methods, and instructions for transmitting a signal by an electronic apparatus that include generating transmission data and pseudo-random data corresponding to the transmission data, setting a first pseudo time delay interval for the transmission data and a second pseudo time delay interval for the pseudo-random data, acquiring a data signal for transmitting the transmission data to correspond to the first pseudo time delay interval and a pseudo-random signal for transmitting the pseudo-random data to correspond to the second pseudo time delay interval, and transmitting an overlapping signal including the data signal and the pseudo-random signal.

A method for transmitting data carrying optical information over an optical channel, comprising the steps of providing an optical transmitter consisting of a light source being a Mode-Locked Optical Frequency Comb (MLFC) for generating a frequency comb of multiple carriers, each of which being modulated by a baseband signal; an optical modulator for modulating each and all of the multiple carriers in a modulation bandwidth extending up to the modes' frequency spacing between the multiple carriers; performing all-optical encoding of the modulated carriers by manipulating the optical amplitude and/or phase and/or polarization of all optically modulated carriers; and transmitting, by the optical transmitter, the encoded modulated carriers to an optical receiver, over an optical channel.

Methods, systems, and devices for wireless communications are described. A first wireless device may communicate, with a second wireless device, a first set of messages of a first message type that are acknowledged according to an acknowledgement procedure. The first wireless device, the second wireless device, or both may select a first subset of messages of the first plurality of messages and a first subset of bits from each message of the first subset of messages based on the first set of messages being acknowledged and according to a sampling configuration common to both the first wireless device and the second wireless device. The first wireless device, the second wireless device, or both may generate a key using bit values of the first subset of bits from each message of the first subset of messages, encoding a message using the key, and communicate the encoded message.

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.

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.

This application discloses a method and an apparatus for processing an audio signal. The method includes obtaining a first speech signal acquired by a first device; performing frame blocking on the first speech signal, to obtain multiple speech signal frames; converting the multiple speech signal frames into multiple first frequency domain signal frames; performing aliasing processing on a first sub-frequency domain signal frame among the multiple first frequency domain signal frames with a frequency lower than or equal to a target frequency threshold, and retaining a second sub-frequency domain signal frame among the multiple first frequency domain signal frames with a frequency higher than the target frequency threshold, to obtain multiple second frequency domain signal frames, the target frequency threshold being related to a sampling frequency of a second device; and performing frame fusion on the multiple second frequency domain signal frames, to obtain a second speech signal.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless device may receive a beamformed signal from a transmitting device. The wireless device may estimate a weighted sum based at least in part on one or more coefficients that relate to impairments associated with the transmitting device, a spatial location of the wireless device, and/or the like. The wireless device may determine a cryptographic key based at least in part on a ratio among the plurality of coefficients in the weighted sum, and one or more communications between the wireless device and the transmitting device may be secured based on the cryptographic key. Numerous other aspects are provided.

A method for unbiased interviewing involves, during an interview of an interviewee: capturing an interviewee utterance, generating a voice-modulated interviewee utterance from the interviewee utterance, transmitting the voice-modulated interviewee utterance to an interviewer processing system, capturing an interviewee image, and transmitting the interviewee image to a backend processing system.