Abstract: Methods and devices for processing a signal. The methods include supplying to a first modulator a first RF signal and a first optical signal, wherein the first modulator is configured to output a first output signal; generating a first intensity signal that is based on the first output signal, wherein the first intensity signal is further based on a first biasing parameter; and providing a first intensity signal to a first analog-to-digital converter (ADC) to create a first digital signal processable by a signal processing unit.

Abstract: An umbilical having a plurality of sensors (single, multi-component, or distributed) disposed in a sealed encapsulant, optionally with “accessories” or connectors at the ends, and the methods or manufacturing and deploying such an umbilical for seismic imaging in geological formations and other applications.

Abstract: An umbilical having a plurality of sensors (single, multi-component, or distributed) disposed in a sealed encapsulant, optionally with “accessories” or connectors at the ends, and the methods for manufacturing and deploying such an umbilical for seismic imaging in geological formations and other applications.

Abstract: Key management and user authentication systems and methods for quantum cryptography networks that allow for users securely communicate over a traditional communication link (TC-link). The method includes securely linking a centralized quantum key certificate authority (QKCA) to each network user via respective secure quantum links or “Q-links” that encrypt and decrypt data based on quantum keys (“Q-keys”). When two users (Alice and Bob) wish to communicate, the QKCA sends a set of true random bits (R) to each user over the respective Q-links. They then use R as a key to encode and decode data they send to each other over the TC-link.

Abstract: A medical voice data system includes a hand-held recording device, an electronic information carrier (EIC), and a host station. The hand-held device records medical information from a user that is examining a person in an extreme environment such as battlefield or disaster area. EICs are stored within a housing interior and can be dispensed therefrom by the user. Recording electronics within the housing interior are operably connected to at least one of the EICs. A microphone is operably connected to the recording electronics to record on a EIC medical information about the injured person. The EIC is configured to be attached to and travel with the person as they are evacuated so that the recorded medical information is immediately available to medical personnel at a care center via the host station. The medical voice data system may also employ a wireless EIC. A host station is used to receive and process the recorded information and convert it to text-based medical record.

Abstract: A medical voice data system includes a hand-held recording device, an electronic information carrier (EIC), and a host station. The hand-held device records medical information from a user that is examining a person in an extreme environment such as battlefield or disaster area. EICs are stored within a housing interior and can be dispensed therefrom by the user. Recording electronics within the housing interior are operably connected to at least one of the EICs. A microphone is operably connected to the recording electronics to record on a EIC medical information about the injured person. The EIC is configured to be attached to and travel with the person as they are evacuated so that the recorded medical information is immediately available to medical personnel at a care center via the host station. The medical voice data system may also employ a wireless EIC. A host station is used to receive and process the recorded information and convert it to text-based medical record.

Abstract: Systems and methods for enhanced quantum key distribution (QKD) using an actively compensated QKD system. The method includes exchanging quantum signals between first and second QKD stations and measuring the quantum signal error. An error signal SE representative of the system visibility error is then generated. An error-signal threshold STH that defines a system visibility error limit is then selected. Those qubits measured with the condition SE>STH are called “above-threshold” qubits, while those qubits measured with the condition SE?STH are called “below-threshold” qubits. Only below-threshold qubits are stored and used to form the final quantum key. This is accomplished by sending a blanking signal SB to the memory unit where the qubits are stored. The blanking signal prevents above-threshold qubits from being stored therein. The raw quantum key so formed has few errors and thus forms a longer final quantum key for a given number of exchanged quantum signals.

Abstract: A fast bit-error rate (F-BER) calculation mode for a QKD system is disclosed, wherein the method includes establishing versions of a sifted key in respective sifted-bits (SB) buffers in respective QKD stations (Alice and Bob). The method also includes sending Alice's version of the sifted key to Bob, and Bob performing a comparison of the two sifted key versions. The number of bit errors between the two sifted key versions relative to the length of the sifted key yields the F-BER. The F-BER is calculated much more quickly than the conventional BER calculation (“N-BER”), which involves performing a relatively complex error-correction algorithm. The F-BER calculation mode is particularly useful in quickly setting up and/or calibrating a QKD system, and can be repeated quickly to provide updated BER measurements after each QKD system adjustment.

Abstract: A quantum key distribution (QKD) cascaded network with loop-back capability is disclosed. The QKD system network includes a plurality of cascaded QKD relays each having two QKD stations Alice and Bob. Each QKD relay also includes an optical switch optically coupled to each QKD station in the relay, as well as to input ports of the relay. In a first position, the optical switch allows for communication between adjacent relays and in a second position allows for pass-through communication between the QKD relays that are adjacent the relay whose switch is in the first position.

Abstract: A method for enhancing the security of a quantum key distribution (QKD) system having QKD stations Alice and Bob. The method includes encrypting key bits generated by a true random number generator (TRNG) and sent to a polarization or phase modulator to encode weak optical pulses as qubits to be shared between Alice and Bob. Key bit encryption is achieved by using a shared password and a stream cipher. Bob obtains at least a subset of the original key bits used by Alice by utilizing the same stream cipher and the shared password.

Abstract: A method of integrating quantum key distribution (QKD) with Internet protocol security (IPSec) to improve the security of IPSec. Standard IPSec protocols impose limits on the frequency at which keys can be changed. This makes efforts to improve the security of IPSec by employing quantum keys problematic. The method includes employing multiple security associations (SA) in in-bound and outbound SA Tables in a manner that enables a high key flipping rate and that enables combining quantum keys with classical keys generated by Internet Key Exchange (IKE), thereby enabling QKD-based IPSec.

Abstract: Key management and user authentication systems and methods for quantum cryptography networks that allow for users securely communicate over a traditional communication link (TC-link). The method includes securely linking a centralized quantum key certificate authority (QKCA) to each network user via respective secure quantum links or “Q-links” that encrypt and decrypt data based on quantum keys (“Q-keys”). When two users (Alice and Bob) wish to communicate, the QKCA sends a set of true random bits (R) to each user over the respective Q-links. They then use R as a key to encode and decode data they send to each other over the TC-link.

Abstract: Systems and methods for exchanging and processing encoded quantum signals in quantum key distribution (QKD) systems in real time. A stream of quantum signals is sent from Alice to Bob. Alice only encodes sets or “frames” of the streamed quantum signals based on receiving a “ready” message from Bob. This allows for Bob to finish processing the previous frame of data by allowing different bit buffers to fill and then be used for data processing. This approach results in gaps in between frames wherein quantum signals in the stream are sent unencoded and ignored by Bob. However, those quantum signals that are encoded for the given frame are efficiently processed, which on the whole is better than missing encoded quantum signals because Bob is not ready to receive and process them.

Abstract: Systems and methods for enhanced quantum key distribution (QKD) using an actively compensated QKD system. The method includes exchanging quantum signals between first and second QKD stations and measuring the quantum signal error. An error signal SE representative of the system visibility error is then generated. An error-signal threshold STH that defines a system visibility error limit is then selected. Those qubits measured with the condition SE>STH are called “above-threshold” qubits, while those qubits measured with the condition SE?STH are called “below-threshold” qubits. Only below-threshold qubits are stored and used to form the final quantum key. This is accomplished by sending a blanking signal SB to the memory unit where the qubits are stored. The blanking signal prevents above-threshold qubits from being stored therein. The raw quantum key so formed has few errors and thus forms a longer final quantum key for a given number of exchanged quantum signals.

Abstract: A QKD cascaded network (5) with loop-back capability is disclosed. The QKD system network includes a plurality of cascaded QKD relays (10, 20, 30) each having two QKD stations Alice (A) and Bob (B) therein. Each QKD relay also includes an optical switch (50). The optical switch is optically coupled to each QKD station in the relay, as well as to the input ports (PI) of the relay. In a first position, the optical switch allows for communication between adjacent relays. In a second position, the optical switch allows for pass-through communication between the QKD relays (10 and 30) that are adjacent the relay whose switch is in the first position. Also in the second position, the optical switch allows for communication between the QKD stations A and B within the relay. This, in turn, allows for diagnostic measurements to be made of one or both of the QKD stations via an optical path (90) that is entirely within the relay station enclosure (12, 22, 32).

Abstract: A QKD system having QKD link redundancy between two sites, with the system having only one QKD station at each site, and with two or more QKD links operably coupled to the QKD stations. The QKD stations have respective optical switches that are optically coupled to both QKD links and that are controlled by respective controllers in each of the QKD stations. If one of the QKD links fails or has trouble transmitting optical signals, the QKD switches are switched so that the optical path between the QKD stations uses the remaining QKD link. This arrangement requires only two QKD stations rather than the four QKD stations as presently taught in the prior art.

Abstract: Systems and methods that allow for transmitting qubits and classical signal over the same channel of an optical telecommunications network that includes an optical fiber. The method includes sending the qubits of wavelength ?S over a quantum optical path that includes the optical fiber during a time interval ?T0 when there are no classical optical signals of wavelength ?S traveling over the optical fiber. The method also includes sending the classical signals over a classical optical path that includes the optical fiber, wherein the classical signals are sent outside of the time interval ?T0 to avoid interfering with the qubit transmission. Systems and methods for using the present invention to form quantum key banks for encrypting classical signals sent over the optical telecommunications network are also disclosed.

Abstract: Systems and methods for exchanging and processing encoded quantum signals in quantum key distribution (QKD) systems in real time. A stream of quantum signals is sent from Alice to Bob. Alice only encodes sets or “frames” of the streamed quantum signals based on receiving a “ready” message from Bob. This allows for Bob to finish processing the previous frame of data by allowing different bit buffers to fill and then be used for data processing. This approach results in gaps in between frames wherein quantum signals in the stream are sent unencoded and ignored by Bob. However, those quantum signals that are encoded for the given frame are efficiently processed, which on the whole is better than missing encoded quantum signals because Bob is not ready to receive and process them.

Abstract: A method for enhancing the security of a quantum key distribution (QKD) system having QKD stations Alice and Bob. The method includes encrypting key bits generated by a true random number generator (TRNG) and sent to a polarization or phase modulator to encode weak optical pulses as qubits to be shared between Alice and Bob. Key bit encryption is achieved by using a shared password and a stream cipher. Bob obtains at least a subset of the original key bits used by Alice by utilizing the same stream cipher and the shared password.

Abstract: A method of integrating quantum key distribution (QKD) with Internet protocol security (IPSec) to improve the security of IPSec. Standard IPSec protocols impose limits on the frequency at which keys can be changed. This makes efforts to improve the security of IPSec by employing quantum keys problematic. The method includes increasing the size of the Security Association (SA) Table in a manner that enables a high key change rate so that the quantum keys can be combined with the classical keys generated by Internet Key Exchange (IKE). The invention includes a method of creating the SA Table by combining quantum keys generated by the QKD process with classical keys generated by the IKE process, thereby enabling QKD-based IPSec.