Computer terminal security system

• US 3,984,637 A
• Filed: 11/29/1974
• Issued: 10/05/1976
• Est. Priority Date: 11/29/1974
• Status: Expired due to Term

• Current Assignee: Link Tactical Military Simulation Corporation Existing Under LAWS of Delaware
• Original Assignee: Singer PLC (Hayleys Plc)
• Inventors: Euler, Edwin E., Caudill, Herman T.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Myers, Randall P.
• Application Number:
  US05/528,092
• Time in Patent Office: 676 Days
• Field of Search: 179/2 A, 179/2 DP, 179/2 CA, 179/1.5 R, 179/1.5 E, 179/2 R, 340/149 R, 340/149 A, 235/61.7 B, 445/22 (2), 445/22 (3), 445/22 (5), 445/46 (6), 445/46 (9), 178/22
• US Class Current: 379/93.02
• CPC Class Codes: G06F 21/313 using a call-back technique via a telephone network
• CPC Class Codes: G07C 9/33 by means of a password
• CPC Class Codes: H04L 12/22 Arrangements for preventing the taking of data from a data transmission channel without authorisation means for verifying the identity or the authority of a user of a secure or secret communication system H04L9/32
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 9/3226 using a predetermined code, e.g. password, passphrase or PIN network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083
• CPC Class Codes: H04L 9/3234 involving additional secure or trusted devices, e.g. TPM, smartcard, USB or software token network architectures or network communication protocols for supporting authentication of entities using an additional device in a packet data network H04L63/0853

Abstract

This invention is a security system for computer terminals which system provides means for preventing the unauthorized access to digital computers from illicit terminals. The invention provides a local code unit which includes means for manually selecting a sequence of digits by means of a keyboard. When the selected sequence and the pre-set code in the local code unit are the same, the terminal equipment is connected to the transmission path. This prevents unauthorized personnel at an authorized terminal from gaining access to a transmission path. A second code, pre-set into the code transmitter by any suitable means such as switches, is transmitted over the transmission path to the code receiver. A code receiver at the other end of the transmission path connects the computer to the transmission path only when the second code is the same as the code pre-set into the code receiver.

Claims

1. A communications system security apparatus, said apparatus comprising:

a. a data processor from which information may be entered or removed;

b. a terminal capable of sending or receiving information from said data processor in a given interval of time;

c. an information transmission path adapted to carry information between said data processor and said terminal in a given interval of time;

d. a first manually controllable means for normally conditioning the connection of said data processor to said transmission path and operated to provide a code receiving mode;

e. a first code means located at said terminal having a first predetermined code combination;

f. a second manually controllable means for normally connecting said terminal to said transmission line and operated to connect said first code means to said transmission path;

g. a second code means, located at said terminal, having a second predetermined code combination stored therein and responsive to a selected code combination such that when both said second code combination and said selected code combination are identical said terminal is connected to said transmission path; and

h. a third code means, located at said data processor, having a third predetermined code combination stored therein and connected to said transmission path in said code receiving mode when said first manually controllable means is operated such that said third code means is responsive to said first predetermined code combination when said second manually controllable means is operated to connect said data processor to said transmission path when both said first and second manually controllable means are returned to normal.

2. The apparatus defined in claim 1 wherein said first manually controllable means is a switch.

3. The apparatus defined in claim 1 wherein said second manually controllable means is a switch.

4. The apparatus defined in claim 1 wherein said first code means is a code transmitter.

5. The apparatus defined in claim 4 wherein said code transmitter comprises:

a. a group of double throw decade switches, each of said group of switches including a plurality of individual switches;

b. a shift register having a plurality of digit positions, each of said digit positions being coupled to one of said decade switches;

c. a clock generator coupled to said shift register;

d. a manually controlled start switch connected to the load input of said shift register and to the disable input of said clock generator;

e. a first NOR gate having its output coupled to said clock generator, and one of its inputs coupled to said start switch; and

f. a second NOR gate having its output coupled to the input of said first NOR gate, and one of its inputs coupled to the input of said clock generator, and its other input coupled to said start switch.

6. The apparatus defined in claim 1 wherein said second code means is a local code unit.

7. The apparatus defined in claim 6 wherein said local code unit comprises a series of trigger circuits connected in series in which an output of one trigger circuit is connected to a conditioning input of the next following trigger circuit, a group of switches having one side connected to a source of energy, and means for connecting the other side of each one of said switches to a trigger input of one of said trigger circuits in a preselected sequence to form said first predetermined code combination.

8. The apparatus defined in claim 1 wherein said third code means is a code receiver.

9. The apparatus defined in claim 8 wherein said code receiver comprises:

a. a register that stores said third predetermined code combination;

b. comparator means for comparing the code stored in said code receiver to said first predetermined code combination; and

c. means responsive to a coincidence of said first and third predetermined code in said comparator to connect said data processor to said transmission path.

10. The apparatus defined in claim 1 wherein said information transmission path is a telephone transmission line.