Abstract: The present invention uniquely applies data communications network techniques to a security system. A series of slave transponders are coupled via a full duplex bus to a master node. The master node is coupled to other master nodes to form a network. The master node periodically polls its slave transponders to authenticate them. Each transponder has processing capability to give a distributed processing system. Each master node is a gateway which directs transmissions to the appropriate end point. The system uses an accordion-like protocol which can have fields added or deleted in a specific structure to conform the protocol to the particular message being transmitted. The protocol begins with address bytes indentifying the destination followed by a control field which identifies the fields which are present. For a broadcast, rather than a point-to-point transmission, a process ID field in the protocol determines what area or function has to be addressed in all units.

Abstract: The invention relates to synchronization of encrypted data communication systems and a method which looks for any lack of pattern or intelligent information in the received data and triggers a resynchronization signal based thereon. If the encrypter/decrypter pairs are out of cryptographic synchronization, the received (decrypted) data resembles pseudorandom data. A method and system are provided for detecting such pseudorandom binary data by, for example, ones density. If the data is sufficiently random the system is resynchronized.

Abstract: A integer encryptor and decryptor, with the integer encryptor comprising a pseudorandom source, a discrete-time source, guard-band means, and adding means. The pseudorandom source generates a random-data signal. The random-data signal is an integer that lies within a first-bounded range. The discrete-time source generates the input-data signal. The guard-band means is coupled to the discrete-time source. In response to the input-data signal, the guard-band means generates an output-data signal. For a second-limit number the guard-band means limits the output-data signal to lie within a second-bounded range. The second-limit number is less than the first-limit number. The modulo-adding means is coupled to the pseudorandom source and the guard-band means. The modulo-adding means repetitively adds the output-data signal with the random-data signal and a third-limit number and generates an encrypted-data signal.

Abstract: A configurable connector between two or more devices with at least one of the devices being capable of programming the connector through an interface therewith. The connector contains programmable electronic circuitry capable of being instructed by the device whereby the connector assumes a desired connecting configuration and/or function. In one embodiment the connector is programmed to inquire and determine the configuration of the device to which it is connected. With the results of its analysis the connector adapts the necessary timing, pin-outs, voltages, and other parameters to assure proper communication between the connected devices. In other embodiments the connector contains electronic components to add specific functions for data exchange, such as data buffering, data encryption and the like. In addition, the connector is programmable with interchangeable pin designations thereby obviating the need for rewiring for different applications and physical connections.

Abstract: Apparatus and methods are disclosed for providing privacy on communications systems which include radio links, such as cellular telephone, marine radiotelephone, IMTS, and RDSS systems, in a manner which does not require a scrambler/descrambler at each called party location. The apparatus includes a base module having a call diverter connected to the public switched telephone network through two standard telephone lines. A bypass interface circuit is connected to the call diverter between the connections to the two telephone lines to selectively connect a scrambler/descrambler in series with the two telephone lines.In operation, a mobile telephone, such as a cellular telephone, places a call to the telephone number of the first telephone line to cause the call diverter to place the second line off-hook and supply a dial tone from the second line through the call diverter and the first line back to the cellular telephone.

Abstract: A holographic device and method encrypts a time dependent data signal, s(t), by a complex time dependent phase shifting signal. This produces a new signal whose modulus is equal the absolute value of the data signal, s(t), but has widely spread the frequency of the data signal. This new complex signal is mathematically transformed, producing an amplitude and phase spectrum (or a real and imaginary transform spectrum) of signal components. The amplitude and phase signals are modulated into a radio frequency carrier (or some other radiating source) as quadrature components and transmitted. At the receiver, the quadrature signals are separated into an amplitude and phase components which are then mathematically inverse transformed. The result is a complex signal with a real and imaginary components. The resulting signal is an accurate representation of the original data signal if a complete signal is recovered.

Abstract: A satellite communication system employing a satellite in a geostationary orbit about the earth for communicating with ground stations disposed along a region of the earth positioned along an arc of a great circle of the earth. The satellite carries a frequency-scanning antenna array oriented for scanning a beam of electromagnetic radiation in one plane aligned with the arc of the great circle. Each position of the beam is formed with a different frequency of the radiation. The operating frequency of each ground station is selected to match the frequency of a beam directed from the satellite to the ground station. An antenna assembly formed of two confocal parabolic reflectors provides for a multiplication of the effective aperture of an array of radiating elements of the antenna, and also for a demagnification of a scan angle of radiation emanating from the array of radiating elements.

Abstract: A monolithic microwave integrated circuit having multiple, vetically stacked components wherein at least three metal layers isolated from each other by layers of non-conducting material are formed on a semi-insulating substrate, generally comprised of gallium arsenide. Vertically stacked capacitors, inductors and various combinations thereof may be fabricated using the present invention. Further, the vetrically stacked components may be formed on active devices such as FETs and diodies.

Abstract: In a packet based communication network 10, a key management center 20 is used to distribute cryptographic keys for either a switched virtual circuit or a permanent virtual circuit. The disclosed methods allow the key management center 20 to communicate directly with the data encryption/decryption devices (DE's) 14 even though they operate in a transparent mode (rather than a store and forward mode). This is accomplished by balancing link counters with calls to fictitious addresses and/or use of interrupt packets transferred between the DTE 12 and the DE 14. In permanent virtual circuits, the MAC of the last packet transmitted under the cold cryptographic key is exchanged to synchronize the key change.

Abstract: A high-power high-isolation switch for high-power devices which switch power to one of several alternative output ports. Unwanted leakage is attenuated and high-isolation between the output ports is obtained. In addition, protection against burn-out during abnormally high leakage conditions is provided where the devices employed are not self protecting.

Abstract: A magnetostrictive flexible line hydrophone having a magnetostrictive elet which is an annealed nickel strip within a toroidal winding. Electrical wires are disposed inside the cylinder formed by the nickel strip and abut a pressure release material about which the strip has been wound. These wires form a toroidal winding by coupling to a second group of insulated wires disposed against the outer surface of the nickel strip.

Abstract: An authenticator for digital data is derived by generating a numerical array, using a secret key to controllably shift the relative positions of the elements of the array, and applying the scrambled array to a message to create an authenticator for that message. The method allows a high level of security and minimizes the risk of a system, such as an intelligent portable token and reader system, being compromised.

Abstract: A method for the fast synchronization of vocoders, coupled to each other by means of enciphering and deciphering devices, consists in synchronizing the data frames transmitted by the vocoders with the end of the sequence for synchronizing the enciphering and deciphering devices, in transmitting the decryption data for a period equal to a whole multiple of the duration of a digital frame of speech data transmitted and in synchronizing the called vocoder with the end of transmission of the decryption data. Thus, a gain is obtained in the synchronization acquisition time.

Abstract: A transaction system comprises terminal stations which can communicate with a host exchange. In order to improve the communication, concentrators are arranged between the host exchange and the terminal stations. Given functions can be accommodated within the concentrators so that they need not be provided in the terminal station. The concentrators as well as the terminal stations are provided with a security box in order to realize encryption/decryption of the data transport; for the terminal station this box is preferably realized in the form of a smart card which acts as an operator identification element. A customer can identify himself by means of a user identification element, for example a magstripe card or a further smart card. The encryption mechanism is preferably DES.

Abstract: A computer system uses security labels for evey word in memory. Each access to a memory location requires that the security level of the memory location be compared to that of a process which is making the access. If the security level of the process does not dominate that of the memory location, access is denied. Each time a memory location is modified, it is assigned a security level consistent with the levels of all of the data which was used to modify the memory location.

Abstract: An information encryption method particularly intended for a communication system in which bidirectional multiplexed communications of the point-to-multipoint type are derived between a switching exchange and plural terminal stations. The switching exchange transmits first multiplexed words respectively destined for the terminal stations. The terminal stations supply second words which are multiplexed and transmitted towards the switching exchange. In the switching exchange, informations concerning transmission errors detected in the second words are derived and transmitted towards the terminal stations, and the first words are encrypted as a function of second words previously received free of transmission error in the switching exchange. In each of the terminal stations, the informations concerning the transmission errors are detected, and the second words transmitted from the terminal station and received free of transmission error by the switching exchange are memorized.

Abstract: A power-on password security function for a digital computer system allows the system software to distinguish between authorized and unauthorized users. Safeguards are made against corruption of password data which could lead to lock-out authorized users, and redundant checks allow the security function to operate even when first-level checks fail. The battery-powered RAM storage area used to hold the password when the system is turned "off" is protected against being accessible by unauthorized users when the system is turned "on".

Abstract: A method of scrambling a television signal is provided in which, during a horizontal blanking interval and during a vertical blanking interval, a video signal is compressed and a key signal containing information concerning the compression is superimposed on an audio signal in the horizontal blanking period. The method is characterized by superimposing a pseudo-key signal on an audio signal in the vertical blanking interval, making the key signal contain information concerning the position of a vertical blanking interval, and fixing a video signal in a predetermined number of horizontal scanning periods before a vertical synchronizing signal portion in the vertical blanking interval at a constant level while eliminating color bursts in a predetermined number of horizontal scanning periods before and after the vertical synchronizing signal portion in the vertical blanking interval. In this way, unauthorized users are prohibited from receiving the signal, and unauthorized access is made difficult.

Abstract: A system for electronically transmitting data objects such as computer programs with a means for verifying that the computer program was actually received and the terms and conditions of its use accepted by the receiver is presented. In this system, the computer program itself controls the verification for its receipt and acceptance. The sender first modifies the program to be delivered, rendering it non-executable in the form in which it will be received by the user initially. The sender inserts into the program an enabling routine and a verification indicia. The enabling routine is capable of rendering the non-executable program into an executable state if certain prerequisite conditions, contained in the verification and enabling routine, are met.

Abstract: The invention provides independent guidance and monitoring to be integrated into an MLS landing system and also provides a scaled-down MLS landing guidance system useable at small airports. In both cases an added fixed beam precision guidance system is integrated into the MLS time sequence format. The fixed beam guidance system is based upon the concept of using paired fixed overlapping beams, sequentially radiated by different fixed antennas. One pair is oriented to left and right of the centerline of the runway, and the other pair is oriented above and below the desired glideslope. The first set of paired beams overlap at the centerline of the runway in such a manner that an aircraft approaching exactly on centerline will intercept equal signal intensities to indicate an on-course approach.