Abstract: Key escrow is achieved without a key escrow facility. An escrow key pair is generated and stored in the terminal. A key escrow field that includes a traffic key encrypted with the escrow key is provided before encrypted traffic is communicated. When access to the traffic key is authorized, the escrow key is extracted from the terminal and used to decrypt the traffic key. The private portion of the escrow key is covered in the terminal with an escrow key access number. The escrow key access number is preferably generated by the terminal manufacturer with a secret algorithm using the terminal serial number. Alternatively, the escrow key is stored within a user token, rather than the terminal.

Abstract: An apparatus is disclosed for continuous load optimization of wireless communication networks by making use of statistical data about both the communication medium characteristics and the characteristics of messages that users desire to send over the network. The network comprises a network control base station (20) and a plurality of slave stations (22). One or more applications (72, 104) are associated with each station which are used to generate the messages in digital format. Each application is coupled to a protocol stack (88) that defines the required characteristics of the data and changes to the data that occur during the communication process. An interface (90) is coupled to the layers of each protocol stack (88) to allow tuning of the message characteristics to maximize successful transmission with minimum message latency.

Abstract: An interface between a digital communication system and a PSTN establishes a user configurable secure encrypted link to a digital subscriber unit through the digital communication system, and provides clear (unencrypted) voice to telephone sets through the PSTN. The interface includes a security module for encrypting and decrypting information with user specific algorithms and keys, a transcoder for converting modulated voice to digital voice and a modem for modulating and demodulating data and encrypted voice. Accordingly, the wireline interface allows for user specified security over a digital wireless portion of an end-to-end communication channel. The interface also provides for the communication of unencrypted voice followed by secure voice or secure data.