Computer terminal security system

• US 4,430,728 A
• Filed: 12/29/1981
• Issued: 02/07/1984
• Est. Priority Date: 12/29/1981
• Status: Expired due to Fees

• Current Assignee: Marathon Oil Company 539 South Main St Findlay Oh
• Original Assignee: Marathon Oil Company (Marathon Oil Corporation)
• Inventors: Bruce, Charles R., Cook, Gary R., Beitel, James E., Sartore, Edward L., Mosier, Charles F. Jr.
• Primary Examiner(s): Chan, Eddie P.
• Application Number:
  US06/335,972
• Time in Patent Office: 770 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 340/825.3, 340/825.31, 340/825.34, 178/22.01, 178/22.08, 178/22.09, 178/4.1 B, 179/2 A, 179/2 C, 179/2 CA, 179/2 DP, 179/1 C, 179/1.5 R, 179/1.5 E
• US Class Current: 379/93.02
• CPC Class Codes: G06F 21/31 User authentication

Abstract

The invention provides a system for securing the access of a remote computer terminal (130) to a centrally located host computer (300). The system includes a first security circuit (200) interconnected with a calling telephone (100), a calling modem (110), and the remote computer terminal (130) at the remote location for automatically dialing the number of the called telephone (310) at the location of the central host computer (300). A second security circuit (350) is located at the central host computer (300) and is interconnected with the called telephone (130), the called modem (330), and the central host computer (300). Upon receipt of the user identification code, the second security circuit (350) compares the user identification code with a stored code and, if verified, sends an acknowledgment signal back to the first security circuit (200). At this time, the two security circuits (200 and 350) activate respective solid state switches (260 and 370) to interconnect the host computer (300) with the remote computer terminal (130). A portable memory module (240) is selectively insertable in the first security circuit (200) to selectively activate and deactivate the first security circuit and which contains the secret phone number of the called telephone (310) at the host computer (300) as well as the secret user identification code.

Claims

1. An improved computer terminal security system interconnected with at least one terminal computer having a calling telephone and a calling modem at a remote location and further interconnected with a host computer having a called telephone connectable to said calling telephone over phone lines and a called modem, a plurality of first removable memory modules, a first security circuit connected to said at least one terminal computer, a second security circuit connected to said host computer, and said first security circuit being powered and operative only when any one of said first removable memory modules are inserted, said improved computer terminal security system comprising:

said first removable memory module containing the secret telephone number of said called telephone, a secret user identification code, and remote sequencing program instructions, said first memory module being further capable of being selectively erased and reprogrammed to incorporate different telephone numbers, user identification codes and remote sequencing program instructions in the event of a loss of secrecy,

said first security circuit being further connected to said calling modem and to said calling telephone, said first security circuit comprising;

(a) first receiving means for selectively receiving said first memory module,

(b) a switch,

(c) first processing means connected to said first receiving means and to said switch and responsive to the activation of the switch for causing the first processing means to retrieve said remote sequencing program instructions, said secret user identification code, and said secret called telephone number from said first memory module, and for executing said sequencing program instructions for generating dialing means, delivering means, and first interconnecting means control signals,

(d) dialing means connected to said calling telephone and receptive of said dialing means control signals and secret called telephone number from said first processing means for automatically dialing said called telephone through said calling telephone and over said phone lines,

(e) delivering means connected to said calling telephone and receptive of said delivering means control signals and said secret user identification code from said first processing means for delivering said secret user identification code over said phone lines to said called telephone, and

(f) first interconnecting means connected to said first processing means, to said calling modem, and to said terminal computer and receptive of said first interconnecting control signals for selectively interconnecting said terminal computer to said calling modem, said calling modem being connected to said calling telephone,

a second removable, erasable and programmable memory module for containing a plurality of secret user identification codes and host sequencing program instructions, said second memory module capable of being selectively erased to incorporate different user identification codes and host sequencing program instructions in the event of said loss of secrecy, and

said second security circuit further being connected to said called modem, and to said called telephone, said second security circuit comprising;

(a) second receiving means for selectively receiving said second memory module, said second security circuit being operable only when said second removable memory module is inserted,

(b) second processing means connected to said second receiving means and receptive of said host sequencing program instructions and of said plurality of secret user identification codes for executing said host sequencing program instructions,

(c) answering means connected to said called telephone and to said second processing means for automatically answering said calling telephone, said second processing means being further receptive of said delivered user identification code from said delivering means for comparing said delivered user identification code to the codes in said plurality of secret user identification codes and said second processing means being further capable of generating an acknowledgment signal when said delivered user identification code matches one of said plurality of user identification codes,

(d) sending means connected to said called telephone and receptive of said acknowledgment signal from said second processing means for sending said acknowledgment signal through said called telephone over said phone lines to said first interconnecting means, said first interconnecting means upon receipt of said acknowledgment signal becoming activated to selectively interconnect said terminal computer to said calling modem, and

(e) second interconnecting means connected to said second processing means, to said called modem, and to said host computer for becoming activated and interconnecting said host computer with said called modem only in response to said sending of said acknowledgment signal, said called modem being connected to said called telephone so that said host computer and said terminal computer can communicate over said phone lines, said host computer being accessible by said terminal only after said first and second interconnecting means become activated.

2. An improved computer terminal security system interconnected with at least one terminal computer having a calling telephone and a calling modem at a remote location and further interconnected with a host computer having a called telephone connectable to said calling telephone over phone lines and a called modem, a plurality of first removable memory modules, a first security circuit connected to said at least one terminal computer, a second security circuit connected to said host computer, and said first security circuit being powered and operative only when any one of said first removable memory modules are inserted, said improved computer terminal security system comprising:

said first removable memory module containing the secret telephone number of said called telephone, a secret user identification code, and remote sequencing program instructions, said first memory module being further capable of being selectively erased and reprogrammed to incorporate different telephone numbers, user identification codes and remote sequencing program instructions in the event of secrecy loss,

first security circuit being further connected to said calling modem and to said calling telephone, said first security circuit comprising;

(a) first receiving means for selectively receiving said first memory module,

(b) a switch,

(c) first processing means connected to said first receiving means and to said switch and responsive to the activation of the switch for causing the processing means to retrieve said remote sequencing program instructions, said secret user identification code, and said secret called telephone number from said first memory module and for executing said sequencing program instructions for generating dialing means, delivering means, and first interconnecting means control signals,

(d) dialing means connected to said calling telephone and receptive of said dialing means control signals and secret called telephone number from said first processing means for automatically dialing said called telephone through said calling telephone and over said phone lines,

(e) delivering means connected to said calling telephone and receptive of said delivering means control signals and said secret user identification code from said first processing means for delivering said secret user identification code over said phone lines to said called telephone, and

(f) first interconnecting means connected to said first processing means, to said calling modem, and to said terminal computer and receptive of said first interconnecting control signals for selectively interconnecting said terminal computer to said calling modem, said calling modem being connected to said calling telephone,

said second security circuit being further connected to said called modem and to said called telephone, said second security circuit comprising;

(a) second processing means containing host sequencing program instructions and a plurality of user identification codes for executing said host sequencing program instructions,

(b) answering means connected to said called telephone and to said second processing means for automatically answering said calling telephone, said second processing means being further receptive of said delivered user identification code from said delivering means for comparing said delivered user identification code to the codes in said plurality of user identification codes and said second processing means being further capable of generating an acknowledgment signal when said delivered user identification code matches one of said plurality of user identification codes,

(c) sending means connected to said called telephone and receptive of said acknowledgment signal from said second processing means for sending an acknowledgment signal through said called telephone over said phone lines to said first interconnecting means, said first interconnecting means upon receipt of said acknowledgment signal becoming activated to selectively interconnect said terminal computer to said calling modem, said terminal computer being disconnected from said calling modem at all other times, and

(d) second interconnecting means connected to said second processing means, to said called modem, and to said host computer for becoming activated and interconnecting said host computer with said called modem only in response to said sending of said acknowledgment signal, said host computer being disconnected from said called modem at all other times, said called modem being connected to said called telephone so that said host computer and said terminal computer can communicate over said phone lines, said host computer being accessible by said terminal only after said first and second interconnecting means become activated.

3. An improved computer terminal security system interconnected with at least one terminal computer having a calling telephone and a calling modem at a remote location and further interconnected with a host computer having a called telephone connectable to said calling telephone over phone lines and a called modem, a plurality of first removable memory modules, a remote security circuit connected to said at least one terminal computer, a host security circuit connected to said called modem, and said remote security circuit being powered and operative only when any one of said first removable memory modules are inserted, said improved computer terminal security system comprising:

said first removable memory module for containing the secret telephone number of said called telephone, a secret user identification code, and remote sequencing program instructions, said first memory module capable of being selectively erased and reprogrammed to incorporate different telephone numbers, user identification codes and remote sequencing program instructions in the event of secrecy loss,

said remote security circuit connected to said calling modem and to said calling telephone, said remote security circuit comprising;

(a) first receiving means for selectively receiving said first memory module,

(b) a switch,

(c) first processing means connected to said first receiving means and to said switch and responsive to the activation of the switch for causing the first processing means to retrieve said remote sequencing program instructions, said secret user identification code, and said secret called telephone number from said first memory module and for executing said sequencing program instructions for generating dialing means, delivering means, and remote interconnecting means control signals,

(d) dialing means connected to said calling telephone and receptive of said dialing means control signals and called telephone number from said first processing means for automatically dialing said called telephone through said calling telephone and over said phone lines,

(e) delivering means connected to said calling telephone and receptive of said delivering means control signals and said secret user identification code from said first processing means for delivering said user identification code over said phone lines to said called telephone, and

(f) remote interconnecting means connected to said first processing means, to said calling modem, and to said terminal computer and receptive of said remote interconnecting control signals for selectively interconnecting said terminal computer to said calling modem, said calling modem being connected to said calling telephone,

said host security circuit connected to said called modem and to said called telephone, said host security circuit comprising;

(a) a host processing means containing sequencing program instructions and a plurality of selectively changeable user identification codes for executing the aforesaid sequencing program instructions,

(b) answering means connected to said called telephone and to said second processing means for automatically answering said calling telephone, said second processing means being further receptive of said delivered user identification code from said delivering means for comparing said delivered user identification code to the codes in said plurality of user identification codes and said second processing means being further capable of generating an acknowledgment signal when said delivered user identification code matches one of said plurality of user identification codes,

(c) sending means connected to said called telephone and receptive of said acknowledgment signal from said second processing means for sending an acknowledgment signal through said called telephone over said phone lines to said first interconnecting means, said first interconnecting means upon receipt of said acknowledgment signal becoming activated to selectively interconnect said terminal computer to said calling modem, said terminal computer being disconnected from said calling modem at all other times, and

(d) host interconnecting means connected to said second processing means, to said called modem, and to said host computer for becoming activated and interconnecting said host computer with said called modem only in response to said sending of said acknowledgment signal, said host computer being disconnected from said called modem at all other times, said called modem being connected to said called telephone so that said host computer and said terminal computer can communicate over said phone lines, said host computer being accessible by said terminal only after said first and second interconnecting means become activated.