Precomputed and distributed security system for a communication network

摘要

In a data communication network, a system for protecting parts of the network. The system comprises a plurality of user nodes linked together within the network. Each user node comprises means for transmitting list indicating to other nodes in the network the identification of allowed senders and receivers; and two or more security nodes within the network; each security node detects transmission and relays each signal only to the recipients specified in the list.