Patents Represented by Attorney Eric Froehlich
  • Patent number: 8069349
    Abstract: A method of securely transferring files from an un-trusted to a trusted network is disclosed. A file that is an archive file of many component files is separated into constituent files. Each file is stored on a server connected to an un-trusted network, and a series of initial checks, such as virus, file size, and file extension are performed. If the files pass, additional, file format specific security rules are applied. An open format transform is performed on proprietary format type files, and embedded file components are separated out. A user-definable security rule set is performed on each open format transform component. If all security tests pass, the file is reassembled and saved as a trusted file in the same format as the original file.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: November 29, 2011
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventors: Jeffrey Israel, Colin Richmond, Darrel Sharpe, Wohlgemuth Erik
  • Patent number: 8068850
    Abstract: A method of locating a transmitter is disclosed. A communications link is established between multiple receiving stations and a control station, and used with a calibration signal to calibrate out the time delay of the communications link. A radiated signal from an unknown transmitter is received at a receiving station and sent to the control station over the communications link. The time of arrival is recorded. Upon receiving a user input, the communication link switches from transmitting the received radiated signal to transmitting the calibration signal. The start of calibration signal is timed to begin at the same time across all of the receiving stations. The communication link time delay for each link is calculated by subtracting the start time from the received time, and the communication link time delay is subtracted from the received time recorded for the radiated signal. TDOA calculations are made to locate the transmitter.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: November 29, 2011
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventors: Walter J Kleinfelder, James E Meister
  • Patent number: 7945947
    Abstract: A method of giving a user high-level access privileges if a combination of keystrokes is sent to a desktop is disclosed. Each terminal services session is enumerated and sessions identified. Unidentified sessions have a user-definable process associated with the session. Desktops registered in the terminal services session are identified, and if a new desktop is identified, a thread is created to attach to that desktop and hook the desktop's low-level keyboard input. The keyboard input is then monitored for a pre-defined combination of keystrokes, and if found, a command shell starts, giving the user higher-level access privileges.
    Type: Grant
    Filed: December 3, 2007
    Date of Patent: May 17, 2011
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventor: Eric B. Chudow
  • Patent number: 7930538
    Abstract: A method of securely transferring files from an un-trusted to a trusted network is disclosed. A file that is an archive file of many component files is separated into constituent files. Each file is stored on a first computer connected to an un-trusted network, and a series of initial checks, such as virus, file size, and file extension are performed. If the files pass, the file is transferred to a second server using a one-way file transfer mechanism. A series of secondary checks, similar to the initial checks is performed on each file transferred. For text files or images, a simplified security rule is applied. An open format transform is performed on proprietary format type files, and embedded file components are separated out. A user-definable security rule set is performed on each open format transform component. If all security tests pass, the file is reassembled and transferred to the trusted network.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: April 19, 2011
    Assignee: The United States of America as represented by the Director of the National Security Agency
    Inventors: Jeffrey Israel, Colin Richmond, Darrel Sharpe, Erik Wohlgemuth
  • Patent number: 7734671
    Abstract: A method of sorting text for memory efficient searching is disclosed. A FM-index is created on received text, and a number of rows are marked. The locations of the marked rows are stored in data buckets as well as the last column of the FM-index, which is stored as a wavelet tree. Data blocks containing the data buckets are created; containing the number of times each character appears in the data block before each data bucket. A header block is created comprising an array of the number of times each character appears in the last column of the FM-index before each data blocks, the location of the end of the data blocks and the location of the end of the data, and appended to the data block. The header and data blocks are stored. The search process loads data buckets into memory as needed to find the required text.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: June 8, 2010
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventor: Michael P. Ferguson
  • Patent number: 7734991
    Abstract: A method of encoding a communication signal by selecting a cyclic code, establishing a generator polynomial, generating a polynomial using the generator polynomial, forming a matrix from the generated polynomial, receiving data to be encoded, appending zeros to the received data, calculating a syndrome of the matrix, calculating check values from the syndrome, appending the check values to the received data, and encoding the received data with appended check values using the generator polynomial.
    Type: Grant
    Filed: January 4, 2007
    Date of Patent: June 8, 2010
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventor: Donald W. Newhart
  • Patent number: 7715996
    Abstract: The present invention is a novel method of performing spectral analysis on a digital signal. The received signal is segmented into a number of data blocks, which may be disjoint or overlapping. For each data block, the signal is differentiated, and the Gram-Schmidt process is used to obtain orthogonality between a signal and its derivative. The complex extension leads to computation of phase using either the inverse tangent function or the complex logarithm. Finally, frequency estimation follows through differentiation of the unwrapped phase.
    Type: Grant
    Filed: September 27, 2007
    Date of Patent: May 11, 2010
    Assignee: The United States of America as represented by the Director of the National Security Agency
    Inventor: Adolf Cusmariu
  • Patent number: 7694207
    Abstract: A method of correcting a communication signal with BCH product codes is disclosed. The method comprising the steps of receiving a codeword vector, establishing a generator polynomial, establishing a check polynomial, calculating a binary-matrix, and calculating the binary syndrome S=Hrt. If an all zero vector results, no errors exist in the received vector. If errors exist, a tm x (N?k) binary matrix is created, the power basis expansion of (r(?1), r(?3), r(?5), . . . r(?2t?1)) is calculated, and the syndrome is solved. The speed of the method comes from using word-level XOR's to apply the check polynomial to the stream at all offsets. The utility of this approach is due in part to the fact that the conversion matrix involved can be created quickly using only items needed elsewhere in BCH decoders: a field table and the generator polynomial coefficients.
    Type: Grant
    Filed: September 25, 2006
    Date of Patent: April 6, 2010
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventors: Jason Michael Kline, Donald W. Newhart, Nicholas Paul Nirschl
  • Patent number: 7642986
    Abstract: Range limited antenna includes at least two sets of antenna elements and an RF signal processing network connected to each set of antenna elements. The network has a function, F(?,x)=?A(x)??B(x)+?C(x)??D(x) . . . +?N?1(x)??N(x), where x is a signal, ?A(x) is the phase angle of signal x at the first element set, ?B(x) is the phase angle of signal x at the second element set, ?N(x) is the phase angle of signal x at the set N, and ? contains all additional parameters which bear on the system. The network is configured to pass a signal for which F(?,x)>?, where ? is a threshold amount, such that the antenna has gain to signals within a radius and has attenuation outside the radius.
    Type: Grant
    Filed: September 19, 2007
    Date of Patent: January 5, 2010
    Assignee: The United States of America as represented by the Director, National Security Agency
    Inventor: Mark L. G. Althouse
  • Patent number: 7607858
    Abstract: An enhanced security manhole cover is disclosed, comprising a frame, outer cover, inner cover, crossbar, saddle, eyebolt, and padlock. The inner cover, which closes the lower opening in a manhole, includes a detent in the top surface for receiving the eyebolt. The crossbar is positioned above the inner cover and engages the walls of the frame. The crossbar includes a threaded hole that aligns with the detent. The saddle, an upside down U-shaped member, is positioned over the crossbar and includes a slot for the eyebolt to partially extend through. The saddle may include a shoulder on the base, to protect the eyebolt. The eyebolt passes partially through the saddle and crossbar and threads into the bore. The shackle of the padlock passes through holes in the upright of the U-shaped saddle below the crossbar, locking the saddle in place. The upper cover closes the top of the frame.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: October 27, 2009
    Assignee: The United States of America as represented by the Director, The National Security Agency
    Inventors: Gary S. Mosholder, Thomas Zuby
  • Patent number: 7581089
    Abstract: A method of protecting a return address on a computer stack is disclosed. Two stacks are created, the first a normal stack, and the second, or shadow, having shadow frames containing the return address upon a subroutine call, the address on the first stack where the return address is stored, and a user-definable state variable which is used to identify a shadow frame as a return address. Before returning from a subroutine, the two return addresses are compared, and if they do not match, the second stack is searched down, and then up, for a matching return address. If there is a match, the shadow is re-synchronized with the first stack by comparing the stored values of the first stack pointer with the first stack pointer and adjusting appropriately the shadow stack pointer. The matching shadow frame must also be a return address datatype of return address.
    Type: Grant
    Filed: April 18, 2007
    Date of Patent: August 25, 2009
    Assignee: The United States of America as represented by the Director of the National Security Agency
    Inventor: Andrew H. White
  • Patent number: 7400194
    Abstract: An efficient method of amplifying a digital signal with reduced electromagnetic interference is disclosed. The invention applies an average amplitude detector to the input signal to control the clock frequency of a pseudo-random number generator so that the clock signal decreases when the average amplitude of the signal increases. The input signal and the pseudo-random number generator are compared to generate a control signal for a switching power amplifier followed by a low-pass filter. When the average amplitude of the input signal falls below a pre-determine threshold, the switching amplifier is placed in a sleep mode.
    Type: Grant
    Filed: June 8, 2006
    Date of Patent: July 15, 2008
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: Richard John Kuehnel
  • Patent number: 7383026
    Abstract: A novel single wideband retroreflector is disclosed that eliminates the need for a local oscillator and a local transmitter. The wideband retroreflector of the present invention comprises an antenna, a circulator, and a mixer. An externally produced continuous wave radio wave transmission within the microwave-millimeter wave frequency band is modulated with a wideband signal with a minimum operating instantaneous bandwidth of 5 KHz-500 MHz and retransmitted as a modulated waveform by the antenna.
    Type: Grant
    Filed: October 17, 2005
    Date of Patent: June 3, 2008
    Assignee: The United States of America as represented by the Nation Security Agency
    Inventors: John Lewis Detch, Hugh Warren Schwartz
  • Patent number: 7350689
    Abstract: A reusable tamper-evident envelope includes a first substrate, a second substrate superimposed on the first substrate, at least one auxiliary substrate superimposed on and joined along one edge to the second substrate, and at least one seal along all but one edge joining the first substrate to the second substrate. Each auxiliary substrate is spaced a user-defined distance from the top edge of the first substrate. A perforation line, extending from the left side to the right side of both the first substrate and second substrates facilitate removal of a portion of the respective substrates. After an item is placed into the envelope, the user-activated seal along the remaining edge joins the first substrate to the second substrate. Subsequent uses are possible by removing portions of the first substrate and second substrate along the perforation lines and activating the auxiliary user-activated seal along the auxiliary substrate joining the first substrate to the second substrate.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: April 1, 2008
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: Stephen Richard Campbell
  • Patent number: 7346311
    Abstract: A novel single frequency repeater is disclosed that eliminates the problems of feedback and concurrent oscillation. The single frequency repeater of the present invention comprises a backplane, a first antenna, a filter, an amplifier, a power supply, a switch, and a second antenna. The first antenna, filter, amplifier, power supply, and switch are mounted to one side of the backplane. Preferably, the backplane is electrically grounded. The second antenna is mounted on the second side of the backplane, in an orthogonal direction to the first antenna on the first side of the backplane. By placing the first antenna in the back lobe of the second antenna, separating the first antenna and the second antenna with the grounded backplane, and mounting the second antenna in an orthogonal orientation to the first antenna, problems with feedback and concurrent oscillation have been overcome.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: March 18, 2008
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: Hugh Warren Schwartz
  • Patent number: 7283015
    Abstract: An impedance matching device comprises a dielectric material having a ground plane affixed to one surface, a microstripline conductor disposed on an opposite surface, and a movable dielectric plate. The movable dielectric plate has a higher dielectric constant than the dielectric material, a user-selectable shape, and a conductive coating on the top surface. The bottom surface of the movable dielectric plate engages a portion of the microstripline conductor, and is movable transversely to the microstripline conductor to increase or decrease the impedance of the microstripline conductor and linearly to change the phase of the microstripline conductor.
    Type: Grant
    Filed: September 22, 2005
    Date of Patent: October 16, 2007
    Assignee: The United States of America as Represented by the National Security Agency
    Inventor: Craig A. Rockenbauch
  • Patent number: 7201410
    Abstract: A reusable tamper-evident security device for use on a door or container includes a pair of base members, a pair of first leg members, a pair of second leg members, a pair of U-shaped upper members, and a pair of removable security label blanks. A base member, a first leg member, a second leg member, and a U-shaped upper member are abutted, form an inner cavity between the base member and the U-shaped upper member. At least one mounting hole is provided to affix the base member to the door or container. A first guide and a parallel second guide extent perpendicularly from the top surface of the base member, allowing the removable security label blank to be slidably inserted. The U-shaped upper member abutting each base member is oriented to form an oblong shape when the two base members are adjacent the other. An optional security label may be applied to the removable security label blank.
    Type: Grant
    Filed: January 28, 2005
    Date of Patent: April 10, 2007
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: David Lassen
  • Patent number: 7129742
    Abstract: A novel majority logic circuit is disclosed to determine whether the majority of the inputs are a one, within a constant number of clock cycles, regardless of the number of inputs. The majority logic circuit according to the present invention includes a plurality of current mirror stages and an amplifier stage. For each input, one current mirror stage is used, which outputs either a current source if the input is a one, or a current sink if the input is a zero. The current sources of all the input current mirror stages are connected in parallel to the current source input node of the amplifier stage. The current sinks of all the input current mirror stages are connected in parallel to the current sink input node of the amplifier stage. The amplifier is a differential type, which outputs either a positive voltage or a zero voltage depending upon the majority of the inputs.
    Type: Grant
    Filed: February 23, 2005
    Date of Patent: October 31, 2006
    Assignee: The United States of America as represented by the National Security Agency
    Inventor: Richard John Kuehnel
  • Patent number: 7005652
    Abstract: The present invention is a sample-stage for a scanning electron microscope. The sample stage has a U-shaped base, horizontally oriented with the closed end forming the right side. A bottom member abuts the bottom of the U-shaped base, forming an interior cavity with the U-shaped base. An angled support member abuts the top of the U-shaped base farthest from the right side for holding a sample at a user-defined angle. A first reflector abuts a portion of the interior right side of the U-shaped base, and a second reflector abuts a portion of the top surface of the bottom member. A beam stop abuts a portion of the right side of the U-shaped base.
    Type: Grant
    Filed: October 4, 2004
    Date of Patent: February 28, 2006
    Assignee: The United States of America as represented by National Security Agency
    Inventor: William Edward Vanderlinde