Abstract: Substantially identical numerical sequences known only to stations A and B are generated in a manner not subject to duplication by an eavesdropper and not subject to cryptanalytic attack because they are not derived using a mathematical function (such, as for example, factoring). The sequences are independently derived utilizing a physical phenomena that can only be “measured” precisely the same at stations A and B. Signals are simultaneously transmitted from each station toward the other through a communication channel having a characteristic physical property capable of modifying the signals in a non-deterministic way, such as causing a phase shift. Each signal is “reflected” by the opposite station back toward its station of origin. The effect of the communication channel is “measured” by comparing original and reflected signals. Measured differences are quantized and expressed as numbers.

Abstract: The present invention is directed to realize a stable and highly-efficient quantum communication without being influenced by the jitter of the heralding signal. In regard to the quantum encryption transmitting apparatus 200, the pulse-driven heralded single-photon source 201 generates a photon pair, outputs one photon of the photon pair, and outputs the other photon of the photon pair as a heralding signal. The timing adjuster 202 synchronizes the heralding signal with a clock signal for pulse driving the pulse-driven heralded single-photon source 201, and outputs as a trigger signal. The quantum communication modulating unit 203 implements the signal modulation to a quantum signal, in timing with the trigger signal, and transmits the quantum signal to the quantum encryption receiving apparatus 300 via the quantum communication path 101. The heralding signal transmitting unit 205 transmits the heralding signal to the quantum encryption receiving apparatus 300 via the heralding signal communication path 102.

Abstract: Provided is a polarization coding quantum cryptography system. The quantum cryptography includes a light source, a quantum channel, an optical path selector, and a path-dependent polarization selector. The light source generates a signal light. The quantum channel is used as a path to transmit the signal light to a receiver unit. The optical path selector is disposed between the light source and the quantum channel to transmit the signal light to one of a plurality of propagation paths. The path-dependent polarization selector is disposed between the optical path selector and the quantum channel. Herein, the path-dependent polarization selector is configured to determine the polarization direction of the signal light according to the propagation path of the signal light.

Abstract: The present invention provides an apparatus and method for producing entangled photon pairs via four-wave mixing in optical fiber. The source of entangled photons is designed to be stable with no manual alignment. This is accomplished with proper system design using polarization maintaining fibers or polarization controllers with feedback control. The source may contain a method of switching the output from an unpolarized entangled state to a polarized state, where the polarized state can be used to more easily align subsequent photon measurement systems to the proper configuration for measuring the unpolarized entangled state. The invention further provides a means to engineer the apparatus, including the use of a periodic filter common to both entangled pairs, such that the wavelength spacing between the pairs can be optimized such that multiple pairs can be generated with reduced adverse influence from Raman scattering.

Abstract: A secure, open-air communication system utilizes a plurality of “decoy” data signals to hide one or more true data signals. The true data signal(s) are channel hopped with the plurality of decoy data signals to form a multi-channel “scrambled” output signal that is thereafter transmitted in an open-air communication system. The greater the number of decoy signals, the greater the security provided to the open-air system. Further security may be provided by encrypting both the true and decoy signals prior to scrambling and/or by utilizing a spatially diverse set of transmitters and receivers. Without the knowledge of the channel assignment(s) for the true signal(s), an eavesdropper may be able to intercept (and, with time, perhaps descramble) the open-air transmitted signals, will not be able to distinguish the true data from the decoys without also knowing the channel assignment(s).

Abstract: A controlling device provides conditional access to secured content renderable by an appliance. The controlling device transmits a data frame to the appliance and encrypts at least a part of the data frame that includes data to be used by the appliance to provide access to the secured content. At the appliance a decryption key complimentary to the encryption key is used to decrypt the received the data frame. The appliance allows the secured content to be rendered only after the appliance determines that the data in the received, decrypted data frame includes the data the appliance requires to provide access to the secured content.

Abstract: An apparatus including: an input optical interface configured to receive a series of optical input signals each including photons; an encoder configured to encode a quantum key for distribution by encoding each of the series of received optical input signals with a measurable state; an attenuator configured to attenuate each of the encoded optical input signals to create a series of quantum optical signals; and an output optical interface configured to send the series of quantum optical signals to the remote apparatus via a quantum communication channel.

Abstract: Substantially identical numerical sequences known only to stations A and B are generated in a manner not subject to duplication by an eavesdropper and not subject to cryptanalytic attack because they are not derived using a mathematical function (such, as for example, factoring). The sequences are independently derived utilizing a physical phenomena that can only be “measured” precisely the same at stations A and B. Signals are simultaneously transmitted from each station toward the other through a communication channel having a characteristic physical property capable of modifying the signals in a non-deterministic way, such as causing a phase shift. Each signal is “reflected” by the opposite station back toward its station of origin. The effect of the communication channel is “measured” by comparing original and reflected signals. Measured differences are quantized and expressed as numbers.

Abstract: A data communication apparatus is highly concealable and significantly increases time necessary for an eavesdropper to analyze cipher text. A multi-level code generation section generates, by using predetermined key information, a multi-level code sequence in which a signal level changes so as to be random numbers. The multi-level processing section combines a multi-level code sequence and information data, and generates a multi-level signal having a level corresponding to a combination of the multi-level code sequence and the information data. In the multi-level code generation section, a random number sequence generation section generates a binary random number sequence by using the predetermined key information. A multi-level conversion section generates a multi-level code sequence from the binary random number sequence in accordance with a predetermined encoding rule.

Abstract: A QKD arrangement with a photon source generating entangled idler and signal photons, with two measuring units, one of which receiving the idler photons and the other one receiving the signal photons, and each including an optical module with photon channels, wherein a photon passes a photon channel as a function of its polarization, and a device for detecting the photons in association to its respective photon channel, as well as a time control for timingly adjusting the detection devices; the photon source is adapted for pulsed emission of photon pairs, and an interrupting unit supplying the signal photons to the optical module in pulsed manner is arranged upstream of the other measuring unit, the photon channels in each optical module including delay units with different delay periods, and only one single-photon detector associates the photons to the photon channels on the basis of a time pattern.

Abstract: An apparatus and method for providing security in a Passive Optical Network (PON) using an Enhanced Security Control management entity (ME). In one embodiment, an optical network unit (ONU) comprising: a processor coupled to a memory and configured to exchange security information between the ONU and an optical line terminal (OLT) by using a plurality of attributes in an Enhanced Security Control management entity (ME) in the ONU via an ONU management control interface (OMCI) channel; wherein the plurality of attributes comprise: an OLT crypto capabilities attribute, an ONU selected crypto capabilities attribute, an OLT random challenge table attribute, an ONU authentication result table attribute, an ONU random challenge table attribute, an OLT authentication result table attribute, and a master session key name attribute.

Abstract: A communication system and a timing control method are proposed that optimize timing in a sender and thereby enable information to be stably transmitted at the right timing. Under instructions from a timing controller in a receiver, the timing of driving a phase modulator in a sender is shifted by one step after another, and the then amount of clock shift and result of interference are monitored at the receiver and stored in a memory. The optimum timing is determined based on the stored data. Thus, a clock for driving the phase modulator in the sender can be set at the right timing. This is equivalent to compensating for group velocity dispersion due to wavelength dispersion that occurs when an optical signal channel and a clock signal channel are transmitted by wavelength division multiplexing transmission.

Abstract: Data is encrypted onto an electromagnetic beam by providing an electromagnetic beam having a signal component having a modal state, wherein the signal component is susceptible to accumulation of a geometric phase, and a reference component, transmitted along a path over at least part of which the signal component accumulates a geometric phase by transformation of its modal state from a first to a second modal state, from the second to at least one further modal state, and then back to the first modal state; and modulating with the data the geometric phase so accumulated, by modulating the modal state transformations. Data is decrypted from a received electromagnetic beam by corresponding processing of the received electromagnetic beam and by comparing an overall phase of the signal component with an overall phase of the reference component so as to retrieve the modulation.

Abstract: A data communication apparatus wherein stealthiness is enhanced by significantly increasing the time required for a wiretapper to decrypt an encrypted text. The data communication apparatus is constituted by connecting a data transmitting apparatus and a data receiving apparatus via a transmission path. The data transmitting apparatus receives a first predetermined initial value (key information) and information data, generates a multi-valued signal, the level of which varies substantially in a random number manner, and converts the multi-valued signal to a modulated signal of a predetermined modulation format for transmission. The data receiving apparatus demodulates the modulated signal to output the multi-valued signal, and then reproduces the information data from the multi-valued signal and a received second predetermined initial value (key information).

Abstract: The invention relates to a node device (21) for a network (20) comprising quantum cryptographic connections (1) provided with quantum channels (4) and public channels (5), comprising quantum optics means (11) for connecting to the respective quantum channels, for generating secrets or keys by means of quantum cryptography, comprising means (13) for managing symmetrical secrets or keys, cryptography means (14) for generating cryptograms, and driver means (15) connected thereto for transmission via a public channel, wherein the means (15) for managing symmetrical secrets or keys and the cryptography and driver means (14; 15) are combined in a common node module (24) as central components (13, 14, 15) for a plurality of quantum channel connections, while the quantum optics means (11) are provided separately in decentral modules (23) for the plurality of quantum channel connections.

Abstract: In a quantum cryptography communication apparatus, a light pulse is generated by a light source and split into a signal light pulse and a reference light pulse on a receiving side. The signal light pulse and the reference light pulse are transmitted to a sending side via a communication channel. On the sending side, the received reference light is passed through a first optical path and phase-modulated by a randomly selected amount. Communication information is acquired on the basis of the reference light passed through the first optical path and the signal light passed via a second optical path. Frequencies of the signal light pulse and the reference light pulse are shifted. The intensity of the signal light pulses is attenuated and phase-modulated by an amount corresponding to the communication information. The resultant signal light pulse and the reference light pulse are returned back to the receiving side.

Abstract: A transceiver comprises a transmitter configured to transmit data signals, a receiver configured to receive data signals, and a controller configured to encrypt a string and supply the encrypted string to authenticate the transceiver.

Abstract: Provided is a quantum encryption communication apparatus of a transmission side which performs a communication process based on quantum encryption, including: a light source unit which generates a light pulse; a polarization modulating unit which performs polarization modulation of the light pulse by using a variable wavelength plate; and a controller which drives the variable wavelength plate to convert a polarization state of the light pulse to one of a plurality of predetermined polarization bases at random.

Abstract: In a system carrying out cryptography communication using a quantum, it is aimed to correctly verify a quantum state received at the commit phase according to the quantum bit string commitment system, even if not maintaining the quantum state until the open phase but immediately observing the quantum state. According to the present invention, the quantum cryptography communication system includes a sending device 1 and a receiving device 2 connected by a quantum communication channel 11 and a classical communication channel 12. A carrier sending unit 14 of the sending device 1 sends a quantum to the quantum communication channel 11, a carrier receiving unit 17 of the receiving device 2 receives the quantum and observes its quantum state.

Abstract: Excitation light is split into two components with mutually orthogonal polarization. One component is fed clockwise and the other component is fed counterclockwise into a polarization maintaining loop. A second-order nonlinear optical medium disposed in the loop generates up-converted light from each excitation component by second harmonic generation, and generates down-converted light from the up-converted light by spontaneous parametric down conversion. A polarization manipulation unit manipulates the polarization direction of at least one of the excitation or down-converted components. The clockwise and counterclockwise components of the down-converted light are recombined and output as quantum entangled photon pairs having substantially the same wavelength as the excitation light. The optical components can be optimized for operation at this wavelength without the need to consider the shorter wavelength of the up-converted light.

Abstract: A secure optical communication system and method are disclosed. Short optical pulses are first modulated with data, then dispersed in time so that they spread out over multiple bit periods, then the desired code is applied to the dispersed pulses. The encoding may include frequency shifts or phase shifts or other. The dispersed optical symbols overlap in time so an applied code chip thus acts on multiple symbols simultaneously. There are generally multiple code chips per dispersed symbol. The coding device does not need to be synchronized to the data rate. Multiple wavelength division multiplexed channels may be encoded simultaneously. The signal propagates to a decoder that is synchronized with encoder to apply a complementary code thereby canceling out the effect of the encoder. The encoder and decoder can be realized by varying the wavelength of an optical pump to a parametric amplifier, allowing for a wide-band frequency shift.

Abstract: A quantum key distribution system comprises a source of entangled photon pairs and two single-photon detectors. The source is coupled to each of the single-photon detectors by optical fiber. Operational systems parameters include the efficiency of the first single-photon detector, the efficiency of the second single-photon detector, and the maximum average number of photon pairs per unit time generated by the source. To characterize the operational systems parameters, the transmittances between the source and each single-photon detector are determined. The dark count probability of the first single-photon detector and the dark count probability of the second single-photon detector are determined. The count probability at the first single-photon detector, the count probability at the second single-photon detector, and the coincidence count probability are determined as a function of the optical power from the source.

Abstract: A quantum repeater includes a transmitter portion including a source, a set of matter systems, and an optical system. The source produces a probe pulse in a probe state having components with different photon numbers, and each matter system has at least one state that interacts with photons in the probe pulse to introduce a change in a phase space location of the probe state. The optical system can direct the probe pulse for interaction with one of the matter systems and direct light from the matter system for transmission on a first channel.

Abstract: A cryptography method using a quantum phenomenon, which performs a multi-staged polarization process between a transmitter and a receiver to prevent a third party from knowing the polarization value of a photon. A transmitter rotates a photon flux by arbitrary angle ? and transmits it to a receiver. The receiver rotates the received photon flux by arbitrary angle ? and transmits it to the transmitter. The transmitter rotates the received photon flux by the reverse angle ?? of an angle, by which the transmitter 10 rotated it, then rotates it by polarization corresponding to an information bit, and transmits it to the receiver which rotates the received photon flux by the reverse angle ?? of an angle, and measures the polarization of the photon flux corresponding to the information bit, and recovers the information bit transmitted by the transmitter. Cryptography information may be transmitted using a plurality of photon fluxes.

Abstract: A method of autocalibrating the timing of the laser in a quantum key distribution (QKD) system is disclosed. The laser generates photon signals in response to a laser gating signals from a controller. The method includes first performing a laser gate scan to establish the optimum laser gating signal arrival time corresponding to an optimum bit-error rate when exchanging photon signals between encoding stations of the QKD system. Once the optimum laser gating signal arrival time is determined, the laser gate scan is terminated and laser gate dithering is initiated. Laser gate dithering involves varying the arrival time of the laser gating signal around the optimum value of the arrival time. Laser gate dithering provides minor adjustments to the laser gating signal arrival time to ensure that the system operates at or near the optimum bit-error rate.

Abstract: In order to overcome the limitation of the prior art quantum key terminal equipment not being able to operate across different segments, the present invention discloses a quantum cryptography service network implementation technique to let a point-to-point quantum key equipment in one segment be redesigned to cooperate with other quantum key equipment in other segments to form a quantum key service network. As opposed to the prior art technique of having each segment generates its own quantum key, the present invention can map one pair of quantum key equipment with another pair of quantum key equipment, or map multiple pairs of quantum key equipment connected in series to have quantum keys entirely or partly shared by the quantum key equipment. Therefore, the generated quantum keys can be used across different segments. Each node in the quantum key service network can provide the quantum key to nearby telecommunication equipment in the telecommunication network of the same premises.

Abstract: Provided is a method for setting a security channel between an OLT and at least one ONU in an EPON. In detail, a channel is generated by which the OLT makes a reciprocal security capability agreement with the ONU that wants to set a security channel in a discovery interval and then automatically registers the ONU with the security capability agreement. The security channel is set by which the OLT distributes an encryption key for the security with the ONU completed with the security capability agreement. A renewal point of the encryption key is shared by transmitting a message indicative of a time to change the encryption key between the OLT and the ONU both completed with the encryption key distribution.

Abstract: Communications having high security against information leakage can be established in a current optical fiber network in the following manner. (1) A sender and a receiver share a seed key in advance, and then transmit and receive random numbers superimposed on carrier light accompanied with fluctuations, where transmission basis is determined by a random number. The sender and the receiver check a shared basis determined by the seed key with a random basis and employ only a random number signal superimposed on a slot for the shared basis that coincides with the random basis, and share the random numbers between the sender and the receiver. Here, since the carrier light has fluctuations, a bit error exists in the received signals. However, because of the seed key, a legitimate receiver can receive a signal with a bit error rate smaller than an eavesdropper.

Abstract: A system stores pedigrees that include details of how and when each of multiple blocks of encryption key material were distributed between two endpoints using quantum cryptographic techniques. The system receives an indication of a possible quantum cryptographic security violation and accesses the stored pedigrees to identify one or more of the multiple blocks of encryption key material that may have been compromised.

Abstract: Entanglement-based QKD systems and methods with active phase tracking and stabilization are disclosed wherein pairs of coherent photons at a first wavelength are generated. Second harmonic generation and spontaneous parametric downconversion are used to generate from the pairs of coherent photons entangled pairs of photons having the first wavelength. Relative phase delays of the entangled photons are tracked using reference optical signals. Classical detectors detect the reference signals while single-photon detectors and a control unit generate a phase-correction signal that maintains the relative phases of phase-delay loops via adjustable phase-delay elements.

Abstract: In various embodiments, a secure optical communication system is disclosed. Such a system may include a photon-pair generation circuit configured to generate pairs of photons with each photon pair including a first-channel photon and a second-channel photon, a transmitting circuit configured to receive first-channel photons, and modulate the first-channel photons according to a stream of data using a first optical circulator to produce first-modulated photons, and a receiving circuit configured to receive second-channel photons, pass the second-channel photons through a complementary optical circulator to produce second modulated photons, and detect relative timing between the first-modulated photons and the second modulated photons to recover the stream of data.

Abstract: The invention provides an apparatus and method for time delaying different polarization components of a signal relative to one another, comprising a polarization signal splitter which splits first and second polarization components of an input signal into a first component signal and a second component signal such that said first component signal propagates along a first path and the second component signal propagates along a second path, wherein said first component signal reaches a location relative to when said second component reaches said location at times differing by a delayed time, and use of the apparatus in a communication system. The apparatus may be used for quantum cryptography, to convert a sender's polarization-qubit signal into a signal appropriate for channels and receivers based on phase-encoded schemes.

Abstract: A QKD system (10) having two QKD stations (Alice and Bob) optically coupled by an optical fiber link (FL), wherein Bob includes a variable timing delay arranged between Bob's controller (CB) and modulator (MB) or detector unit (40). A set-up and calibration procedure is performed wherein delay DL2 is adjusted until the timings for the modulator and detector unit (TSB and TS42, respectively) are established. Delay DL2 is then fixed so that the detector unit and modulator operate in a common timing mode that is not changed if the synchronization signal is changed. The timing TSS of the synchronization (sync) signals (SS) sent from Alice to Bob is adjusted to arrive at optimum system performance. Once the QKD system is in operation, because the sync signal can drift, the sync signal timing TSS is dithered maintain optimum QKD system performance.

Abstract: A system and a method for quantum key distribution between a transmitter and a receiver over wavelength division multiplexing (WDM) link are disclosed. The method includes providing one or more quantum channels and one or more conventional channels over the WDM link; assigning a different wavelength to each of the one or more quantum channels and each of the one or more conventional channels; transmitting single photon signals on each of the one or more quantum channels; and transmitting data on each of the one or more conventional channels. The data comprises either conventional data or trigger signals for synchronizing the transmission of the single photon signals on the quantum channels. All channels have wavelengths around 1550 nm. The WDM link can be a 3-channel WDM link comprising two quantum channels for transmitting single photon signals and one conventional channel for transmitting conventional data or triggering signals.

Abstract: A multi-class switching system that includes a coder/decoder for converting voice between analog and digital; a first switch coupled to the coder/decoder to isolate non-secure entities in a dial-up network, including fiber optic ports to pass classified and unclassified data to one of a classified IP network and an unclassified IP network, an encryption device coupled to the first switch to encrypt digitized voice, a second switch coupled to the encryption device and directly to the first switch, wherein the second switch receives encrypted digital voice from the encryption device connection and unencrypted digital voice from the direct connection, and wherein the first switch and the second switch operate in a plurality of states including secure, non-secure, and cut-off, a fiber optic (F/O) switch coupled to the coder/decoder, and at least one controller to control states of the first switch, the second switch, and the fiber optic (F/O) switch.

Abstract: The present invention discloses a free-space quantum communication device with atomic filters which are used in the field of quantum cryptography. The free-space quantum communication device of the present invention includes a beam splitter (2), two ?/2 wave plates (3,10), a ?/4 wave plate (4), two polarization beam splitters (5,11), two atomic filters (6,12), two light couplers (7,13), two optical fibers (8,14) and two single-photon detectors (9,15). In the present invention, the interference filter used in the conventional quantum communication device is replaced by ultra-narrow line-width atomic filters. As the pass-band width of atomic filter is narrower than that of the interference filter in magnitude order of 3 and a light noise rejection ratio of 10?5 can be obtained, error rate generated by background light noise can be reduced by magnitude order of 2-3. Further, the distance for carrying out free-space quantum communication can be increased.

Abstract: Mechanisms for providing a subscriber-side interface with a passive optical network are described herein. An optical network termination (ONT) having an integrated broadband passive optical network processor is utilized to receive downstream data from an optical line termination (OLT) via a passive optical network and provide the contents of the downstream data to one or more subscriber devices via one or more data interfaces. Similarly, the ONT is adapted to receive and transmit upstream data from the one or more subscriber devices to the OLT via the passive optical network. The ONT preferably implements one or more encryption/decryption mechanisms, such as the digital encryption standard (DES), to provide data protection in addition to, or in place of, data churning provided for by the ITU G.983 recommendations.

Abstract: A system and methods are provided for transmitting an encrypted data word of two or more bits. This involves identifying a random key word comprising two or more bits for encrypting the data word and identifying a set of unique orthogonal codes. This also involves selecting a code from the set of unique orthogonal codes that corresponds to a result of an exclusive-or (XOR) operation between the two or more bits of the data word and the random key word. This also involves encoding a signal with the code and transmitting the encoded signal as encrypted data.

Abstract: A method for optical signal processing includes receiving an optical signal containing a plurality of frequency lines, defining at least two wavesets including an updatable random subset of the frequency lines, receiving a data stream, modulating the optical signal with the data stream, encrypting the data stream by extracting the subset of the frequency lines of the at least two wavesets from the modulated optical signal, and phase coding the subset of frequency lines of the at least two wavesets in the modulated optical signal.

Abstract: A method and apparatus for measuring the optical power of very weak light arriving at a receiver, by using a photon detector, are provided. A photon detector detects the presence or absence of the arrival of a photon in accordance with bias application timing. For a train of optical pulses coming in at an arbitrary timing in respective time slots, the bias application timing is sequentially shifted within the range of a time slot. Each time a shift is made, the number of photons detected is counted by a photon counter. Based on this number of photons, the optical power of the train of the optical pulses is measured.

Abstract: The present invention includes various novel techniques, apparatus, and systems for optical WDM communications that involve dynamically modifying certain aspects of the WDM transmission (and corresponding receive) process at the optical (physical) layer to significantly enhance data/network security. These various dynamic modifications can be employed individually or in combination to provide even greater security depending upon the desired application and design tradeoffs. WDM transmission steps typically include encoding the client signals, mapping them to one or more subchannels within or across ITU channels, modulating them onto subcarrier frequencies, and multiplexing them together for optical transmission. By dynamically modifying one or more of these processing steps over time (in addition to any encryption of the underlying client signals), the current invention provides additional security at the physical (optical) layer of an optical network and thus greatly enhances overall network security.

Abstract: The invention solves the following complicated problems. Elaboration of the procedure for secret key extraction from the lower layer optic signal even in a presence of noise in fiber-optic cable. The realization of the quantum protection amplification scheme to clean states of the entangling polarized photons against noise in optical channels, especially in case of use Einstein-Podolsky-Rozen method with single photon source for transmitting and measuring secret keys photon polarization in ROADM network. The development of a system for code key transmission that satisfies requirements of fortuitousness and privacy along with speed enlargement of the key generation in ROADM network. The achievement of the acceptable optical fiber amplification without losing its behavior and the protocol determination, which will allow to detect and correct bit errors in fiber optic cable and ROADM network, caused by linear and nonlinear effects. The development of quantum encoding systems for telecommunication topologies.

Abstract: An optical communications network incorporating photonic layer security, with secure key exchange without loss of data, and a method of operating the network are disclosed. The network comprises a transmit side and a receive side. The transmit side includes first and second scramblers and a transmit side switch; and the receive side includes first and second descramblers and a receive side switch. The scramblers use encryption keys to encrypt optical signals, and the descramblers use the encryption keys to decrypt the encrypted optical signals. The encryption keys can be updated randomly and at will by installing new encryption keys on the scramblers and descramblers, and the transmit side and receive side switches are synchronized so that all of the optical signals that are encrypted using a new or updated encryption key are decrypted using the same new or updated encryption key.

Abstract: Systems and methods to communicate securely includes communicating quantum encryption data on a first wavelength-division multiplexing passive optical network (WDM-PON); and communicating data over separate classical channels of a second WDM-PON, wherein the second WDM-PON synchronizes with the first WDM-PON while providing data communication over the classical channels.

Abstract: The invention provides a system and method for secure communication that involve encoding and transmitting an optical orthogonal frequency division multiplexed (OFDM) signal. Each subcarrier of an optical carrier in OFDM transmission is modulated with data individually, and a variety of data format are used, such as QPSK, OOK, QAM, etc. The data format of each subcarrier may change in time according to a predetermined pattern. An optical receiver uncovers the data transmitted via an optical link. It is based on a coherent optical receiver and a digital signal processing (DSP) unit. A key to the data mapping and change is transmitted via the same optical link or by a separate channel. In one embodiment, the key is transmitted using quantum encryption technique. Besides subcarrier modulation encoding, the system may provide additional layers of security: optical carrier frequency hopping and polarization scrambling.

Abstract: In general, this disclosure relates to maintaining security between an optical network terminal (ONT) and an optical network aggregation device in an Active Ethernet network. An optical network aggregation device includes one or more optical Ethernet switches that can be adaptively configured to support authentication of one or more ONTs. For example, the optical network aggregation device may include a controller with an authentication unit for managing ONT authentication and an optical Ethernet interface for transmitting and receiving data over the optical network. The authentication unit may exchange authentication request messages via the optical Ethernet interface with an ONT and grant the ONT access to the provider network based on the exchange, thereby preventing rogue devices from gaining access to the provider network.

Abstract: Methods and apparatus are provided for improving both node-based and message-based security in a fibre channel network. Entity to entity authentication and key exchange services can be included in existing initialization messages used for introducing fibre channel network entities into a fibre channel fabric, or with specific messages exchanged over an already initialized communication channel. Both per-message authentication and encryption mechanisms can be activated using the authentication and key exchange services. Messages passed between fibre channel network entities can be encrypted and authenticated using information provided during the authentication sequence. Security services such as per-message authentication, confidentiality, integrity protection, and anti-replay protection can be implemented.

Abstract: An optical fiber secure communication apparatus and a data encryption method therefor are provided. The apparatus comprises a transmitter and a receiver being connected with each other via an optical fiber. The transmitter comprises a PPC processor unit, a field programmable gate array test board, a light-emitting module, an optical fiber coupler and a connection optical fiber. The receiver comprises a wavelength division multiplexer, a connection optical fiber, a photodetector, a field programmable gate array test board, a PPC processor unit and a signal output interface. At the transmitter end, two or more paths of input data are forwarded by the PPC, encrypted by the FPGA and then transmitted to the light-emitting module of two or more wavelengths for conversion from electrical signals into optical signals. At the receiver end, signals of two or more wavelengths enter the photodetector for conversion into electrical signals, which are decrypted by the FPGA and then forwarded by the PPC for output.

Abstract: The resolution obtained by an imaging system utilizing separable photons can be achieved by an imaging system making use of entangled photons. Since resolution is not being increased from the separable-photon system, the imaging system utilizing entangled photons can take advantage of a smaller aperture. This results in a smaller and lighter system, which can be especially valuable in satellite imaging where weight and size play a vital role.

Abstract: A continuous variable quantum encryption key distribution system comprises a sender (Alice) able to randomly choose the phase and the amplitude of each coherent light pulse of a signal, to provide a coherent state defined by a first quadrature and a second quadrature that are random, and to transmit to a receiver (Bob) the signal pulses (S) and a local oscillator (LO), the receiver comprising a homodyne detector (36) for measuring a randomly chosen quadrature of a signal pulse. The sender comprises a device for time-division multiplexing the pulses of the signal (S) and of the local oscillator (LO) to handle the transmission over an optical fiber (10) of the signal and local oscillator pulses to the receiver. The receiver comprises a demultiplexer (31), able to send the received pulses over a first channel (32), or over a second channel (33). The channels are applied as inputs to the homodyne detector (36).