Electronic linkage interface control security system and method

• US 4,672,533 A
• Filed: 12/19/1984
• Issued: 06/09/1987
• Est. Priority Date: 12/19/1984
• Status: Expired due to Fees

• Current Assignee: Communications Link Control Incorporated
• Original Assignee: Communications Link Control Incorporated
• Inventors: Usher, Irwin H., Cole, Garland L., Noble, Richard G.
• Primary Examiner(s): Williams, Archie E.
• Assistant Examiner(s): Munteanu, Florin
• Application Number:
  US06/683,917
• Time in Patent Office: 902 Days
• Field of Search: 178/22.08, 178/22.09, 340/825.34, 375/2.1, 364/200 MS File, 364/900 MS File
• US Class Current: 340/5.74
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G06F 21/34 involving the use of external additional devices, e.g. dongles or smart cards

Abstract

An electronic computer linkage interface control security system that allows a remote computer terminal to control the across to a main computer. The system includes a Computer Linkage Interface Control (CLIC) module that is coupled to the terminal and that generates and stores a random or pseudo-random coupling code that is unique to the terminal and unique for each communication session. The computer, in which the coupling code for the current communications session was stored during the previous session, accesses the current coupling code store in the CLIC module for comparison with the computer'"'"'s previously stored code. If a match occurs, access by the terminal to the main computer is permitted.

Claims

1. A communication linkage interface control circuit, coupled to a data terminal and a computer comprising:

(a) a data transceiver having a receive mode and a transmit mode, for receiving data from and transmitting data to, the computer and the terminal;

(b) a code monitoring circuit, coupled to the transceiver, for monitoring the data flow therein for the occurrence of command codes from the computer matching a set of preset codes;

(c) first latch means coupled to the code monitoring circuit for temporarily indicating the occurrence of a first command code from the computer;

(d) second latch means coupled to the code monitoring means for temporarily indicating the occurrence of a second command code from the computer;

(e) a clock means, coupled to the transceiver, for generating a binary count in response to an increment command, or a preset command and a load command from the computer;

(f) a first controller means, coupled to the first latch means, the transceiver, and the clock means, for alternately enabling the transmit mode of the transceiver means and supplying an increment command to the clock means upon the setting of the first latch means;

(g) second controller means, coupled to the second latch means, the clock means, and the transceiver, for decoding and indicating at least a code generation command, or a load command, and a transmit command from the computer upon the setting of the second latch means; and

(h) code generation and storage means, coupled to the clock means, the second controller means, and the transceiver, for generating and storing a random coupling code upon receipt of a decoded code generation command from the second controller means and sequentially transferring to the transceiver a portion of said random coupling code in response to each preset command, load command, and transmit command decoded by the second controller means from the computer, and for sequentially transferring to the transceiver a portion of the stored coupling code in response to each binary count received from the clock means.