Patents Assigned to MagiQ Technologies, Inc.
  • Patent number: 7602919
    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.
    Type: Grant
    Filed: March 16, 2005
    Date of Patent: October 13, 2009
    Assignee: MagiQ Technologies, Inc
    Inventors: Audrius Berzanskis, Harri Hakkarainen, Keun Lee, Muhammad Raghib Hussain
  • Patent number: 7587049
    Abstract: A one-way stabilized QKD system (10) that utilizes a control signal (CS) and a quantum signal (QS) that travel the same path through the system from a first QKD station (Alice) to a second QKD station (Bob). The control signal is detected at Bob and used to stabilize Bob's side of the interferometer against phase variations. The system also includes a polarization control stage (200) that controls (e.g., scrambles) the polarization of the photons entering Bob. The combination of the polarization control and the active phase stabilization of the interferometer at Bob's end allows for the stable operation of the interferometer when used as part of a one-way QKD system.
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: September 8, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Alexel Trifonov, Anton Zavriyev, Darius Subacius
  • Patent number: 7583803
    Abstract: The quantum key distribution (QKD) systems (200, 300, 400) of the invention includes first and second QKD stations (Alice and Bob) according to the present invention, wherein either one or both QKD stations include fast optical switches (120, 220, 310, 320). Each fast optical switch is respectively optically coupled to two different round-trip optical paths (OP1 and OP2 at Alice, OP3 and OP4 at Bob) of different length that define respective optical path differences OPDA and OPDB, wherein OPDA=OPDB. By switching the fast optical switches using timed switching signals (S1-S3 at Alice, S4-S6 at Bob) from their corresponding controllers (CA at Alice, CB at Bob), the quantum signals—which can be single-photon or weak-coherent pulses—can be generated from a single optical pulse (112), randomly selectively encoded while traversing the optical paths in Alice and Bob, and then interfered and measured (detected) at Bob.
    Type: Grant
    Filed: July 28, 2006
    Date of Patent: September 1, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventor: Alexei Trifonov
  • Patent number: 7577254
    Abstract: A method (300) of performing photon detector autocalibration in quantum key distribution (QKD) system (200) is disclosed. The method (300) includes a first act (302) of performing a detector gate scan to establish the optimum arrival time of a detector gate pulse (S3) that corresponds with a maximum number of photon counts (NMAX) from a single-photon detector (216) in the QKD system (200). Once the optimal detector gate pulse arrival time is determined, then in an act (306), the detector gate scan is terminated and in an act (308) a detector gate dither process is initiated. The detector gate dither act (308) involves varying the arrival time (T) of the detector gate pulse (S3) around the optimal value of the arrival time established during the detector gate scan process. The detector gate dither provides minor adjustments to the arrival time to ensure that the detector (216) produces maximum number of photon counts (NMAX).
    Type: Grant
    Filed: January 29, 2004
    Date of Patent: August 18, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Harry Vig, Jonathan Young, Paul A. Jankovich
  • Patent number: 7570420
    Abstract: Systems and methods for transmitting quantum and classical signals over an optical network are disclosed, wherein the quantum signal wavelength either falls within the classical signal wavelength band, or is very close to one of the classical signal wavelengths. The system includes a deep-notch optical filter with a blocking bandwidth that includes the quantum signal wavelength but not any of the classical signal wavelengths. The deep-notch optical filtering is applied to the classical signals prior to their being multiplexed with the quantum signals to prevent noise generated by the classical signals from adversely affecting transmission of quantum signals in the transmission optical fiber. Narrow-band filtering is also applied to the quantum signals prior to their detection in order to substantially exclude spurious non-quantum-signal wavelengths that arise from non-linear effects in the optical fiber.
    Type: Grant
    Filed: May 11, 2007
    Date of Patent: August 4, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: A. Craig Beal, Michael J. LaGasse
  • Patent number: 7570767
    Abstract: An apparatus (1) and method for decoupling error correction from privacy amplification in a quantum key distribution (QKD 100) system includes two or more computer systems (102, 108) linked by quantum and classical channels (120, 122) where each computer system determines a generalized error syndrome associated with quantum communication between the systems, encrypts the generalized error syndrome using a sequence of values, and communicates the encrypted generalized error syndrome via a classical channel (128) to the other system, which uses the encrypted generalized error syndromes to compute error correction for the quantum transmission.
    Type: Grant
    Filed: December 20, 2002
    Date of Patent: August 4, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventor: Hoi Kwong Lo
  • Patent number: 7570365
    Abstract: A compact, tunable, high-efficiency entangled photon source system that utilizes first and second periodically poled waveguides rather than bulk media in order to decrease the required pump power by up to several orders of magnitude. The first and second waveguides are arranged in respective arms of an interferometer. Each waveguide has partially reflecting ends, and are each placed on the Z-face of respective periodically poled KTP or LiNBO3 crystals to form respective first and second Fabry-Perot cavities. All waves (pump, idler, and signal) are co-polarized along the z-axis of the crystals. One of the waveguides is followed by a polarization rotator (shown as a half-wave-plate in the Figures) rotating the idler and signal wave polarization by 90 degrees. The outputs from two interferometer arms are combined by a polarization beam combiner and then split by a wavelength multiplexer into two spatially separated time-bin and polarization entangled beams.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: August 4, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Alexei Trifonov, Anton Zavriyev
  • Patent number: 7550759
    Abstract: The invention is a sensitive measuring instrument, which is principally applied to quantum computation, especially to measurement of quantum bits consisting of superconducting micro and nano-structures. The state of a quantum bit is expressed as the voltage-time integral over a circuit component. Phase measurement is performed by measuring the capacitance of a single-electron transistor between the gate and ground.
    Type: Grant
    Filed: July 18, 2005
    Date of Patent: June 23, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Pertti Hakonen, Mika Sillanpaa, Leif Roschier
  • Patent number: 7539314
    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.
    Type: Grant
    Filed: August 14, 2006
    Date of Patent: May 26, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Audrius Berzanskis, Brandon Kwok, Harry Vig, Jonathan Young
  • Patent number: 7532400
    Abstract: The invention provides systems and methods enabling high fidelity quantum communication over long communication channels even in the presence of significant loss in the channels. The invention involves laser manipulation of quantum correlated atomic ensembles using linear optic components (110, 120), optical sources of low intensity pulses (10), interferers in the form of beam splitters (150), and single-photon detectors (180, 190) requiring only moderate efficiencies. The invention provides fault-tolerant entanglement generation and connection using a sequence of steps that each provide built-in entanglement purification and that are each resilient to realistic noise levels. The invention relies upon collective rather single particle excitations in atomic ensembles and results in communication efficiency scaling polynomially with the total length of the communication channel.
    Type: Grant
    Filed: October 12, 2007
    Date of Patent: May 12, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Peter Zoller, Luming Duan, Ignacio Cirac, Mikhail D. Lukin
  • Patent number: 7529717
    Abstract: The present invention is directed to systems and methods of providing universal quantum computation that avoid certain external control fields that either are hard or impossible to implement, or are serious sources of decoherence (errors). The systems and methods extend the set of scalable physical platforms suitable for implementing quantum computation in solid state, condensed matter and atomic and molecular physics systems. The invention includes identifying of suitable encodings of logical qubits into three physical qubits—i.e. three quantum mechanical systems of two levels—and performing quantum computing operations by changing the quantum states of physical qubits making up one or more logical qubits using only generalized anisotropic exchange interactions. This includes performing a quantum unitary operation over a single logical qubit or a non-local (entangling) two-qubit unitary operation.
    Type: Grant
    Filed: January 21, 2004
    Date of Patent: May 5, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Jiri Vala, Birgitta Whaley
  • Patent number: 7529373
    Abstract: A method of autocalibrating a quantum key distribution (QKD) system (200) is disclosed. The QKD system includes a laser ((202) that generates photon signals in response to a laser gating signal (S0) from a controller (248). The method includes first performing a laser gate scan (304) to establish the optimum arrival time (TMAX) of the laser gating signal corresponding to an optimum—e.g., a maximum number of photon counts (NMAX)—from a single-photon detector (SPD) unit (216) in the QKD system when exchanging photon signals between encoding stations (Alice and Bob) of the QKD system. Once the optimal laser gating signal arrival time (TMAX) is determined, the laser gate scan is terminated and a laser gate dither process (308) is initiated. The laser dither involves varying the arrival time (T) of the laser gating signal around the optimum value of the arrival time TMAX. The laser gate dither provides minor adjustments to the laser gating signal arrival time to ensure that the SPD unit produces an optimum (e.g.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: May 5, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Jonathan Young, Harry Vig, Michael J. Lagasse
  • Patent number: 7502476
    Abstract: Systems and method of enhancing the security of a QKD system having operably coupled QKD stations (Alice, Bob) using correlated photon pulses (P1, P2) are disclosed. The method includes generating the correlated photon pulses at Alice and detecting one of the pulses (P2) to determine the number of photons in the other pulse (P1). Pulse P1 is then randomly modulated to form a modulated pulse P1?, which is transmitted to Bob. Bob then randomly modulates pulses P1? to form twice-modulated pulses P1?. Bob then detects pulses P1? at select timing slots that correspond to the expected arrival times of pulses P1?, as well as to the number of photons in pulse P1 (and thus in P1?). Bob then communicates with Alice to determine the number N1 of single-photon pulses P1? detected and the number N2 of multi-photon pulses P1? detected. A security parameter (SP) is defined based on the probabilities of detecting single-photon and multi-photon pulses.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: March 10, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventors: Alexei Trifonov, Ekaterina Rogacheva
  • Patent number: 7492904
    Abstract: In a quantum key distribution (QKD) system, a method of autocalibrating the gating of a single-photon detector (SPD) unit is disclosed. The method includes exchanging photon signals (P1, P2) to establish a bit-error rate (BER). The method also includes performing a detector gate signal timing scan (314) that varies the signal arrival time (T) to establish an optimum arrival time (TMIN) corresponding to an optimum (e.g., minimum) BER. Detector gate signal timing dithering is then performed (318). This involves varying the detector gate signal arrival times about the optimum arrival time to ensure that the QKD system operates at or near an optimum BER.
    Type: Grant
    Filed: April 20, 2005
    Date of Patent: February 17, 2009
    Assignee: MagiQ Technologies, Inc.
    Inventor: Jonathan Young
  • Publication number: 20090022322
    Abstract: Entanglement-based QKD systems and methods with active phase tracking and stabilization are disclosed. The method includes generating in an initial state-preparation stage (Charlie) pairs of coherent photons (P1) at a first wavelength. Second harmonic generation and spontaneous parametric downconversion are used to generate entangled pairs of photons (P5) having the first wavelength—State detection stages (Alice and Bob) optically coupled to Charlie receive respective entangled photons from Charlie. The relative phase delays of the entangled photons are tracked using reference optical signals (P3) generated by Charlie and having the same wavelength as the entangled photons. Classical detectors (132A, 132B) detect the reference signals while single-photon detectors (130A, 130B) and a control unit (control unit C) generates an phase-correction signal that maintains the relative phases of the three phase delay loops (40, 100A,100B ) via adjustable phase-delay elements (MA, MB).
    Type: Application
    Filed: January 31, 2007
    Publication date: January 22, 2009
    Applicant: MAGIQ TECHNOLOGIES, INC
    Inventor: Alexei Trifonov
  • Patent number: 7450718
    Abstract: A method of synchronizing the operation of a two-way QKD system by sending a sync signal (SC) in only one direction, namely from one QKD station (ALICE) to the other QKD station (BOB). The one-way transmission greatly reduces the amount of light scattering as compared to two-way sync signal transmission. The method includes phase-locking the sync signal at BOB and dithering the timing of the quantum signals so as to operate the QKD system in three different operating states. The number of detected quantum signals is counted for each state for a given number of detector gating signals. The QKD system is then operated in the state associated with the greatest number of detected quantum signals. This method is rapidly repeated during the operation of the QKD system to compensate for timing errors to maintain the system at or near its optimum operating state.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: November 11, 2008
    Assignee: MagiQ Technologies, Inc
    Inventors: Jonathan Young, Michael J. Lagasse
  • Publication number: 20080273703
    Abstract: Systems and methods of incorporating a QKD system (Q) into a WDM network (2) are disclosed. The methods include electrically gating the single-photon detectors (SPDs) (30, 30?) as well as optically gating the SPDs with optical gates (28, 28?). The electronic gating width (TSPD) and the optical gating width (TOG) are selected to significantly reduce noise from scattered photons. The combined optical and electronic gating of the SPDs provides for Fourier-transform-limited detection of the quantum signal (SQ) that is not otherwise possible in a WDM-QKD system that employs only electronic SPD gating.
    Type: Application
    Filed: September 14, 2005
    Publication date: November 6, 2008
    Applicant: MAGIQ TECHNOLOGIES, INC.
    Inventor: Michael J. LaGasse
  • Patent number: 7447386
    Abstract: A cascaded modulator system (20) and method for a QKD system (10) is disclosed. The modulator system includes to modulators (M1 and M2) optically coupled in series. A parallel shift register (50) generates two-bit (i.e., binary) voltages (L1, L2). These voltage levels are adjusted by respective voltage adjusters (30-1 and 30-2) to generate weighted voltages (V1, V2) that drive the respective modulators. An electronic delay element (40) that matches the optical delay between modulators provides for modulator timing (gating). The net modulation (MNET) imparted to an optical signal (60) is the sum of the modulations imparted by the modulators. The modulator system provides four possible net modulations based only on binary voltage signals. This makes for faster and more efficient modulation in QKD systems and related optical systems when compared to using quad-level voltage signals to drive a single modulator.
    Type: Grant
    Filed: February 23, 2006
    Date of Patent: November 4, 2008
    Assignee: Magiq Technologies, Inc
    Inventors: J. Howell Mitchell, Jr., Harry Vig, Michael J. LaGasse
  • Patent number: 7437081
    Abstract: A system and method for providing two-way communication of quantum signals, timing signals, and public data is provided. Generally, the system contains a first public data transceiver capable of transmitting and receiving public data in accordance with a predefined timing sequence, a first optical modulator/demodulator capable of transmitting and receiving timing signals in accordance with the predefined timing sequence, a first quantum transceiver capable of transmitting and receiving quantum signals in accordance with the predefined timing sequence, and a first controller connected to the first public data transceiver, the first optical modulator/demodulator, and the first quantum transceiver. The first controller is capable of controlling the transmission of the public data, the timing signals, and the quantum signals in accordance with the predefined timing sequence.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: October 14, 2008
    Assignee: Magiq Technologies, Inc
    Inventors: J. Howell Mitchell, Harry N. Vig, Anton Zavriyev, Alexei Trifonov
  • Patent number: 7436961
    Abstract: A method of improving the security of a QKD system is disclosed. The method includes sending synchronization (“sync”) signals from a first QKD station to the second QKD station over a sync signal channel and recording data relating to the arrival times of the sync signals at the second QKD station. The method also includes processing the arrival time data to discern between extra signals in the sync signal channel that were not sent by the first QKD station over the sync channel, and sync signals that were sent by the first QKD station over the sync channel. The method also includes sending an alarm signal when it is determined that extra signals in the sync channel could be due to an attack on the QKD system.
    Type: Grant
    Filed: March 8, 2005
    Date of Patent: October 14, 2008
    Assignee: MagiQ Technologies, Inc.
    Inventors: Howell Mitchell, Harry Vig