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: 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 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 circuit which finds a synchronization pattern and provides synchronized data from incoming time division multiplexed data is disclosed. The incoming data includes an incoming clock signal used in saving the incoming data in a FIFO memory. A local clock, which is isolated from the incoming clock but exhibits substantially the same rate as the incoming clock, retrieves output data from the FIFO memory. A series of bits from the output data which includes bits having relative bit positions that correspond to the bit positions of the synchronization pattern are examined for the occurrence of the synchronization pattern. If the synchronization pattern is not found, a dummy bit is added to the incoming data stream. The added dummy bit causes the quantity of data stored in the FIFO memory to increase the delays the output data by one bit relative to the output data prior to the addition of the dummy bit. The above described process repeats until synchronization is achieved.