Cryptography – Key management – Having particular key generator
Patent
1995-02-21
1996-10-01
Lee, Thomas C.
Cryptography
Key management
Having particular key generator
39520009, 39518211, 39518701, 380 25, 364146, 364147, 364148, 364DIG1, G06F 1300
Patent
active
055617700
ABSTRACT:
A secure front-end communication system which couples a plurality of actively redundant process control computers to a computer network. The system includes a front end computer which is capable of establishing time limited communication contracts with one or more computer entity on the computer network. Each time limited communication contract is based upon an acceptable response to the transmission of an unpredicable signal from the front end computer, such as an encrypted transformation of a psuedo-random number generated by the front end computer. A security table is used to identify the network entities that are permitted to send write command messages to the process control computers to which the front end computer is connected. The front end computer also includes at least one permissive table which is used to determined whether a write command message from the network entity should be transmitted to the process control computer for which the message was intended.
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Bell Brian G.
de Bruijn Ronny P.
Schultz Dale H.
Schulze Oscar E.
van Weele Leonardus A.
Coughlin William J.
Lee Thomas C.
Meky Moustafa Mohamed
Schultz Dale H.
The Dow Chemical Company
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