Abstract: A call is connected between secure terminals (16) through a network (12). If a network address for the call is included on an approved list (46), a secure call setup procedure (54) is performed automatically. One terminal (16) automatically sends an auto-secure signal. If the other terminal detects the auto-secure signal, secure call setup procedure (54) is performed automatically. The secure call setup procedure (54) determines a current user-identity for the opposing party. If the current user-identity corresponds to a user-identity included on an approved list (76), an abbreviated secure call setup process (80) is performed. If the current user identity is not approved, a full secure call setup process (78) is performed. The abbreviated process (80) differs from the full process (78) in that it uses a traffic key obtained from a prior secure communication session and may be performed more quickly.

Abstract: A call is connected between secure terminals (16) through a network (12). If a network address for the call is included on an approved list (46), a secure call setup procedure (54) is performed automatically. One terminal (16) automatically sends an auto-secure signal. If the other terminal detects the auto-secure signal, secure call setup procedure (54) is performed automatically. The secure call setup procedure (54) determines a current user-identity for the opposing party. If the current user-identity corresponds to a user-identity included on an approved list (76), an abbreviated secure call setup process (80) is performed. If the current user identity is not approved, a full secure call setup process (78) is performed. The abbreviated process (80) differs from the full process (78) in that it uses a traffic key obtained from a prior secure communication session and may be performed more quickly.

Abstract: An apparatus for secure communications contains a controller for automatically selecting one of several data ciphering devices utilizing one of a plurality of ciphering algorithms common to transmitting and receiving terminals. A transmitter for transmitting encrypted data, and a receiver for receiving encrypted data are coupled to the plurality of ciphering devices. The controller automatically determines which of the ciphering devices to employ for any given secure communication. The method for establishing a secure communications link includes the steps of exchanging a first message for determining a common key generation and ciphering method and comparing a further shared message for validation of communications terminal security.

Abstract: A method for establishing a secure communications link between first and second terminals includes a step of exchanging a first message. The first message contains information describing encryption devices and communications modes available within the terminals and user authentication information. The method also includes a step of selecting, in at least one terminal, a common key generation and ciphering algorithm. The method further includes steps of exchanging a second message for providing data to form traffic keys, exchanging a third message for synchronizing secure communications and initiating secure communication.

Abstract: A method for passing supervisory control from a first station to a second station of a plurality of stations comprises steps of providing a message header in interstation messages in the first station, transmitting the interstation message from the first station to the second station, processing a message header from the interstation message to extract data and determining present identification of a system controller from the extracted data. The method includes steps of providing a first field containing message identification information, providing a second field containing supervisor station identification information, providing a third field containing update count information and providing a fourth field containing sending station identification information in the message header.

Abstract: An apparatus for secure communications contains a controller for automatically selecting one of several data ciphering devices utilizing one of a plurality of ciphering algorithms common to transmitting and receiving terminals. A transmitter for transmitting encrypted data, and a receiver for receiving encrypted data are coupled to the plurality of ciphering devices. The controller automatically determines which of the ciphering devices to employ for any given secure communication. The method for establishing a secure communications link includes the steps of exchanging a first message for determining a common key generation and ciphering method and comparing a further shared message for validation of communications terminal security.

Abstract: A cryptographic apparatus comprises a linear feedback shift register for providing a pseudo-random code, coupled to a ciphering device, which is in turn coupled to an adder. The ciphering device encrypts the pseudo-random code. One adder circuit input is coupled to a ciphering device, and the other adder circuit input is coupled to the data input. The adder circuit adds data input signals to ciphering device signals to provide output signals. A method for operation of a ciphering engine is described comprising the steps of providing a random number and setting tap weights for a linear feedback shift register, obtaining a pseudo-random bit stream therefrom, and then encrypting the pseudo-random bit stream to generating a traffic key stream. The traffic key stream is added to a data stream to produce encrypted data from plain-text data or, alternatively, the traffic key stream is added to an encrypted data stream to produce plain-text data.

Abstract: An apparatus for secure communications contains a controller for automatically selecting one of several data ciphering means utilizing one of a plurality of ciphering algorithms common to transmitting and receiving terminals. A transmitting means for transmitting encrypted data, and a receiving means for receiving encrypted data are coupled to the plurality of ciphering means. The control means automatically determines which of the ciphering means to employ for any given secure communication. The method for establishing a secure communications link includes the steps of exchanging a first message for determining a common key generation and ciphering method and comparing a further shared message for validation of communications terminal security.

Abstract: A printer/plotter incorporates four individual microprocessor-based print stations, each for printing on a print media a separate color image for superimposition with one another, forming a final full-color image. The four print stations are located along a transport path for single-pass operation, and each print station includes a transport system that allows the media to traverse a print station with controlled forces exerted on the media by that station. The invention further includes a precise registration system wherein each print station monitors registration marks to detect variations of the media (i.e., stretching or shrinkage) during the printing process and to correct for such variations on obtaining accurate registration of the individual images for a full-color result.

Abstract: A cartridge for shielding a portable electronic micro-circuit and for connecting the circuit into a TV game. The apparatus includes a circuit board that is protected within a housing from static electricity and is adapted for connection with an electrical connector on a TV game. The housing includes two parallel members for moving aside a protective shield on the electrical connector and thereby permitting engagement of the circuit board with the connector in the game.