Abstract: A communication system (10) includes a channel (18) that conveys both clear and secure communications and a channel (12) that does not convey clear communications. An interface module (24) resides between these two channels. When a call is attempted through the two channels (12, 18), the module (24) plays a plain-text, audio voice message (54) into the clear side of the call. The message (54) instructs a human operator to take appropriate actions to cause an initiate security setup (ISS) signal (56) to be generated by a secure terminal (28). This message (54) is continuously repeated until the ISS signal (56) is detected at the module (24). The ISS signal (56) includes predetermined frequency components which are notched out of the message (54) so that the ISS signal (56) may be reliably detected at the module (24).

Abstract: A security module for use in a cellular telephone provides for low power consumption. The security module includes a vocoder processor for manipulating signals from the telephone's microphone and to the telephone's ear piece; an encryption engine; a modem processor for controlling transmitted and received data from the cellular telephone; and a security system controller. The processors consume virtually no power when the phone is in the standby mode and very little power to produce encrypted communication when the cellular phone is operational.

Abstract: A cellular voice privacy arrangement includes a digital privacy unit which is part of each subscriber's fixed equipment. The digital privacy unit includes suitable analog to digital and digital to analog converters. A vocoder, digital signal processor and modem provide the privacy. The identification numbers of each terminal (phone) are exclusive-ORed to form a scramble variable. Vocoder data (voice coded information) is exclusive-ORed with the scramble variable to provided scrambled data for transmission.

Abstract: A digital satellite communication system including a local terminal coupled to a radio wireline interface through a radio satellite network. The radio wireline interface connects the radio satellite network to a public switched telephone network and a remote communication terminal. The system includes a novel method of establishing an end-to-end communication channel between local and remote terminals wherein the local terminal establishes a direct digital channel between itself and the radio wireline interface and transmits a message describing its signaling capabilities to the radio wireline interface. The radio wireline interface then trains its modem with the modem of the remote terminal such that the signaling capabilities of the local terminal are not violated. By moving the modem training procedure to the radio wireline interface, modem training response delays caused by the radio satellite network do not affect the success of establishing the end-to-end communication channel.

Abstract: A split key encryption system to crypto-seal a data file comprising a method for unique variable entry (e.g., terminal serial number), random number generation, key storage device, encryption function for combining the unique variable and the random number to generate an encryption variable in an exclusive-OR function using a variable tap linear feedback shift register, and storage function for receiving the encryption variable and the unencrypted data file. A split key decryption system to unseal the crypto-sealed data file comprises a key storage device, terminal, terminal input, and storage function, with decryption again using an exclusive-OR function using a variable tap linear feedback shift register. A comparator allows use of the unencrypted data file only if the decrypted unique variable matches the terminal serial number.

Abstract: Single or multiple blood plasma component concentrations are measured by a disposable stick having one or more blood plasma component reactive areas covered by a semipermeable membrane which is permeable by blood plasma or serum components and impermeable by blood cellular and particulate matter. A second overlay may be superposed with the semipermeable membrane over the reactive areas to receive a blood sample and meter and distribute that sample uniformly to the semipermeable membrane which in turn passes the plasma components uniformly to the reactive areas. The overlays are subsequently separable from the reactive area to remove the cellular components and particulate matter and expose the reactive areas for inspection by, for example, color comparison to standardized charts.

Abstract: Single or multiple blood plasma component concentrations are measured by a disposable stick having one or more blood plasma component reactive areas covered by a semipermeable membrane which is permeable by blood plasma or serum components and inpermeable by blood cellular and particulate matter. A second overlap may be superposed with the semipermeable membrane over the reactive areas to receive a blood sample and meter and distribute that sample uniformly to the semipermeable membrane which in turn passes the plasma components uniformly to the reactive areas. The overlays are subsequently separable from the reactive area to remove the cellular components and particulate matter and expose the reactive areas for inspection by, for example, color comparison to standardized charts.