Abstract: A security key, such as an encryption key, is generated so as to make it more difficult for eavesdroppers to identify the key. Specifically, a cryptographically secure random number generator generates a random bit sequence that is included in a seed. This random seed is provided along with a negotiated master secret to a key generation module. The key generation module may implement a pseudo random function that is in accordance with the Transport Layer Security (TLS) protocol or the Wireless Transport Layer Security (WTLS) protocol. This key may then be used to encrypt a plain text message to form an encrypted data packet. The encrypted data packet also includes the random seed in unencrypted form. The encrypted data packet may be transmitted over a public network to a recipient with reduced risk of eavesdropping.

Abstract: A method to protect the contents of an electronic document through an encryption system based on an initial confusing step in a scrambler and a subsequent diffusion step in a chaotic processor, both steps being of a chaotic type. Initially, encryption keys and an initial chaotic value are acquired; input character strings are acquired; and diffused character strings are calculated using the input character strings, the encryption keys, and previous diffused character strings. After a certain number of iterations, sets of diffused character strings are added to subsequent chaotic values generated by a chaotic processor to obtain encrypted words. Decryption is obtained through two successive operations, wherein the encrypted words are added to chaotic values identical to the encryption values and subtracted from previously decrypted words using an unscrambler element having a structure similar to that of the scrambler and using identical encryption keys.

Abstract: A method for synchronizing a master clock to a slave clock located in master and slave devices communicating with one another via a laser signal beam and a communications channel, each of the devices including a homodyne detector for determining a respective correlation pattern with respect to a phase tuned local oscillator includes steps for recording master and slave correlation patterns while the signal beam cycles between first and second operating modes, transmitting the master correlation pattern and associated first and second times at which the signal beam shifted between the first and second operating modes and between the second and first operating modes over the communications channel, comparing a portion of the master correlation pattern between the first and second times to the slave correlation pattern to thereby determine the time offset between the master and slave correlation patterns, and applying the time offset to the slave clock.

Abstract: A system for synchronizing chaotic transmitters and receivers that is less sensitive to channel effects than other known chaotic communication methods. The system employs duplicate transmitter and receiving modules and in addition to the chaotic output a synchronizing signal which occupies a reduced bandwidth. The small bandwidth affords the system a greater resistance to the affects of frequency dependent channel distortion and noise. The broad band chaotic signal is transmitted and appears to be noise to an unauthorized listener. The receiving unit employs band pass filtering, and when the signal is received the receiver filters the chaotic signal through band pass filters which eliminate channel noise and make gain control easier to implement.

Abstract: A method and apparatus that uses control of a chaotic system to produce secure digital chaotic communication. Controls are intermittently applied by a transmitter-encoder to a chaotic system to generate the 0 and 1 bits of a digital message. A new control/no control bit stream is thereby created in which a 0 indicates that no control was applied and a 1 indicates that a control was applied. The control/no control bit stream and a prepended synchronization bit stream are transmitted, using conventional transmission technologies, from the transmitter-encoder to an identical receiver-decoder. A chaotic system in the receiver-decoder is driven into synchrony and is subject to intermittent controls based on the control/no control bit stream, thereby causing it to generate the digital message.

Abstract: Each of plural CPUs enciphers a plaintext code which is a secrecy object according to chaos block encryption and then enciphers it according to chaos stream encryption. Then, it transmits an obtained cipher code through communication line. On the other hand, each of plural CPUs that received the cipher code synchronously restores the received cipher code according to chaos stream encryption and then restores according to chaos block encryption thereby to obtain an original plaintext code.

Abstract: A method and apparatus for communicating with chaotic and other waveforms employs a filter for estimating a parameter that describes a property of a signal. The filter is constructed by defining a system that models the source of the signal. The system is partitioned into a first subsystem that contains the parameter and a second subsystem that does not contain the parameter, the second subsystem including a term that makes the second subsystem stable and synchronizable with the signal. The signal is introduced as input to the second subsystem and an element of the second subsystem is substituted into a corresponding element of the first subsystem, thereby generating a signal-activated subsystem. An integration factor is introduced to the signal-activated subsystem to cause the parameter to behave as a constant when the signal-activated subsystem with the integration factor is integrated with respect to time.

Abstract: A pseudorandom sequence generator including a first feedback shift register having at least one input and at least one output and a first controller having an output in communication with the at least one input of the first feedback shift register; the first feedback shift register operating at a first speed S1 and the first controller operating at a second speed S2. In one embodiment the first speed S1 of the first feedback shift register is an integer multiple of the second speed S2 of the first controller. In another embodiment the first feedback shift register includes a shift register having an input, an output, and at least one tap; and a feedback function generator having a first input in communication with the at least one tap of the shift register, a second input in communication with the output of the first controller, and an output in communication with the input of the shift register; the feedback function generator includes at least one feedback function.

Abstract: A multiple access communications data and information transport system and methodology for employing the noise present in any conduit as a carrier form using wireless chaotic waveform signals supported by nonlinear noise sustaining structures. The communications system utilizes digital devices and software embodying various algorithms designed to manipulate the nonlinear perturbations of any given conduit to establish a high bandwidth bidirectional, isochronous noise immune communications signal. Additionally, the system can be combined with any of a number of wireless or wireline communication methodologies to further enhance performance in terms of bandwidth, throughput, noise immunity, power consumption, cell size, and number of users without disturbing any concurrent signal traffic.