Abstract: A system and a method are disclosed for protecting the privacy of a wireless data transmission. A request is received from a client device to connect to a base station. A session identification is assigned to the client device and a set of transmission identifications are generated using a block cipher with the assigned session identification and a secret key as input. The transmission identifications identify a frequency channel and a time slot for the client device to wirelessly transmit a message to the base station. The set of transmission identifications are then encrypted and sent to the client device.

Abstract: A keyboard switch system for stenographic machines whereby electrical signals corresponding to key depression may be derived. The switch system is comprised of a plurality of coils each having a coil parameter effecting plunger coaxial therewith and spring loaded to an upper position. The coils are arranged in an assembly so as to be mountable in the stenographic machine with the plunger disposed so as to be contaced and depressed in response to depression of a respective key. Each of the coils form a part of a tuned circuit with plunger position affecting the resonant characteristics so as to create logic levels response to key position.