Digital Computer System Security Device

The present invention relates to a security device for a computer system, more particularly, to the security device which can be operated under a different operating system. The present invention allows a computer system to interface with an input/output device or a file in a normal state while the security device protects the computer system.

The notion of controlling access to computer peripherals via a separate operating system is not new. For example, U.S. Pat. No. 5,434,562 for a Method For Limiting Computer Access to Peripheral Devices to Reardon discloses the use of user operated hardware switches to deny access to peripheral devices. Access to the switches can not be overridden by the computer. The purpose of this arrangement is to prevent unauthorized users or computer viruses from gaining an access to peripheral devices. Reardon '562, however, appears to contain solely mechanical switches without any software to operate them.

Another example is found in U.S. Pat. No. 5,202,997 for a Device For Controlling Access to Computer Peripherals to Arato. A microprocessor requests the user enter a valid identification code in order to gain access to a peripheral. When the user inputs an unauthorized code, the microprocessor will deny access to the peripheral. Arato is an example of software being used to provide security access to computer peripherals.

A similar example is found in U.S. Pat. No. 5,481,253 for an Automotive Security System to Phelan et al. discloses an anti-theft system includes a microprocessor based control module that enables operation of solenoids of the power circuits of the car only if a proper identification code is entered.

Finally, U.S. Pat. No. 5,311,591 for a Computer System Security Method And Apparatus For Creating And Using Program Authorization Information Data Structures to Fischer discloses a program authorization information required to gain access to various terminals. This is to prevent viruses from potentially destroying devices by moving from terminal to terminal. The co-signatory authority may be required in one embodiment as a security measure to prevent unauthorized access to devices.

What is needed is a hardware switching security device that is controlled by software operated under a different operating system so that access to and from peripheral devices may be controlled.

It is an object of the present invention to provide a security device for a digital computer system, operated under a different operating system by using hardware, that protects a computer system while allowing it to interface in a normal state with an input/output device or a file.

These and other objects may be achieved by having a security device for a digital computer system having a peripheral device and peripheral device control means that includes a security user input/output means which displays the contents stored to the peripheral device and receives information for the protection of the peripheral device, a security system control means which is connected to the security user input(output means, and protects and controls the peripheral device, a security control means which is connected to the security system control means, the peripheral device control means and the peripheral device, and protects the peripheral device from being controlled by the peripheral device control means.

A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:

FIG. 1 is a schematic diagram of a digital computer system security device in accordance with the preferred embodiment of the present invention;

FIG. 2 is a security schematic diagram of a hard disk drive of the digital computer system security device in accordance with the preferred embodiment of the present invention;

FIG. 3 is a security schematic diagram of a LAN port of the digital computer system security device in accordance with the preferred embodiment of the present invention;

FIG. 4 is a security schematic diagram of a keyboard/mouse of the digital computer system security device in accordance with the preferred embodiment of the present invention; and

FIG. 5 is a security schematic diagram of a serial port of the digital computer system security device in accordance with the preferred embodiment of the present invention.

In order to protect computer system from an unauthorized access, a screen locking system which interrupts the input of a keyboard and a mouse and a key locking system which restricts the operation of the computer system if the user does not press a set key when booting is used.

Many operating systems are used in one computer system because of the increase of the uses and applications for the computer. Under these systems, the above protecting methods are generally used.

In the above prior art, if the protector is not removed, the user can not use the entire computer system. Also, the above method which is used under one operating system can not be used in another operating system.

A preferred embodiment of the present invention will become apparent from a study of the following detailed description with reference to the accompanying drawings.

As shown in FIG. 1, the security device for a digital computer system having peripheral devices 10 and peripheral device controller 20 which controls the peripheral devices 10, includes a security user input/output unit 30 which displays the contents of peripheral devices 10 and receives information for the protection of the peripheral devices 10, a security system controller 40 which is connected to the security user input/output unit 30, and protects and controls the peripheral devices 10, and security controller 50 which is connected to the security system controller 40, the peripheral device controller 20 and the peripheral devices 10, and protects the peripheral device from being controlled by the peripheral device controller 20.

The peripheral devices 10 include a hard disk drive 12, a Local Area Network (LAN), a LAN port 14 connected to the LAN, a keyboard 15 and mouse 17 (16), and a serial port 18 for serial communication. The peripheral device controller 20 includes a Small Computer System Interface (SCSI) controller 22 for controlling the hard disk drive 12, network controller 24 for controlling the LAN port 14, a keyboard 15 and mouse controller 26 for controlling the keyboard and mouse 17 (16), and serial port controller 28 for controlling the serial port 18. The security controller 50 includes a SCSI security controller 52 which connected to the security system controller 40 and SCSI controller 22, and controls and protects the hard disk drive 12, network security controller 54 which is connected to the security system controller 40 and the network controller 24, and controls and protects the network port 14, keyboard/mouse security controller 56 which is connected to the security system controller 40 and the keyboard/mouse controller 26, and controls the keyboard/mouse 16, and serial port security controller 58 which is connected to the security system controller 40 and the serial port controller 28, and controls and protects the serial port 18.

The security user input/output unit 30 includes a user output unit 32 which receives the contents of the peripheral devices 10 from the security system controller 40 and displays the contents and user input unit 34 which receives information for the protection of the peripheral devices 10 from the user and transmits the information to the security system controller 40.

As shown in FIG. 2, the SCSI security controller 52 transmits and receives data along data busses 66 and 60 when protection enable signal 68 is not activated.

As shown in FIG. 3, the network security controller 54 further includes a multiplexer 80. The multiplexer 80 receives a receive signal 70 among the output of the LAN port 14 and a protection-enable signal 72 among the output of the security system controller 40. Then, the multiplexer 80 outputs the receive signal 70 to the security system controller 40 if the protection-enable signal 72 is activated, and outputs the receive signal 70 to the network controller 24 if the protection-enable signal 72 is not activated.

As shown in FIG. 4, the keyboard/mouse security controller 56 includes a first buffer 88 and a second buffer 90. The first buffer 88 receives a keyboard-clock signal 82 from the keyboard/mouse controller 26, and outputs the keyboard-clock signal 82 if a protection-enable signal 86 from the security system controller 40 is not activated. The second buffer 90 receives a mouse-clock signal 84 from the keyboard/mouse controller 26, and outputs the mouse-clock signal 84 if the protection-enable signal 86 from the security system controller 40 is not activated.

As shown in FIG. 5, the serial port security controller 58 includes a third buffer 98 and a fourth buffer 102. The third buffer 98 receives an output signal 92 from the serial port controller 28, and output the output signal 92 as an output transmit signal 96 if a protection-enable signal 94 from the security system controller 40 is not activated. The fourth buffer 102 receives a receive signal 100 from the serial port 18, and outputs the receive signal 100 to a serial port controller 28 if the protection-enable signal 94 from the security system controller 40 is not activated.

The operation of the security device for a digital computer system in accordance with the preferred embodiment of the present invention is as follows. The user selects the device that has to be protected through the security user input/output unit 30 among the hard disk drive 12, the LAN port 14, the keyboard/mouse 16 and the serial port 18. When the hard disk drive 12 is selected in the above selecting process and a SCSI ID (identification) of the hard disk drive 12 is inputted, the security system controller 40 outputs the Protection-Enable signal 68 and the information of the SCSI ID to the SCSI security controller 52. The SCSI security controller 52 monitors the access of the SCSI controller 22 to the hard disk drive 12. The access of the SCSI controller 22 to the hard disk drive 12 is shown in FIG. 2. The SCSI controller 22 outputs the value of the SCSI ID to a SCSI-Data-Bus 60 and makes the SCSI-SEL signal 62 activated. If the SCSI-SEL signal 62 is activated and the contents of the SCSI-Data-Bus 60 coincides with the value of the SCSI ID, the hard disk drive 12 is connected to the SCSI controller 22 by activating the SCSI-BUSY signal 64. The SCSI security controller 52 monitoring the access of the hard disk drive 12 compares the contents of the SCSI-Data-Bus 60 with the SCSI ID value of the hard disk drive 12 when the SCSI-SEL signal 62 is activated. If the contents of the SCSI-Data-Bus 60 coincides with the SCSI ID value of the hard disk drive 12, the SCSI security controller 52 prevents the SCSI-BUSY 64 signal from being input to the SCSI controller 22. Then, the SCSI security controller 52 resets the SCSI bus 66 and initializes each SCSI signals, so the hard disk drive 12 is protected. If the access to the hard disk drive 12 is sensed, the user is informed of the access to the hard disk drive 12 by an alarm. The result of the above operation is transmitted to the security user input/output unit 30 through the security system controller 40 and is then displayed.

If a network port 14 is selected and inputted among 10Base-T, Thick Network and Thin Network of the network port 14 selected in the above selecting process, the security system controller 40 activates and outputs the protection-enable signal 72. The, the multiplexer 80 of the network security controller 54 receives the activated signal 72 and outputs the receive signal 70 through an output line 74 to the security system controller 40 without connecting with the network controller 24. Therefore, the access to the LAN port 14 is protected. If the access to the LAN port 14 is sensed, the user is informed of the access to the LAN port 14 by an alarm. The user stores the signal 72 from the multiplexer 80 and uses the signal for tracing up the access. The result of the above operation is transmitted to the security user input/output unit 30 through the system controller 40 and is displayed.

If the keyboard/mouse 16 is selected in the above selecting process, the security system controller 40 activates and outputs the protection-enable signal 86. The first buffer 88 provides a clock capable of operating the keyboard 15 by outputting the keyboard-clock signal 82 inputted from the keyboard mouse controller 26. The keyboard-clock signal 82 receives and outputs the activated protection-enable signal 86. However, the first buffer 88 makes the keyboard not operable by interrupting the keyboard-clock signal 82. The second buffer 90 provides a clock capable of operating the mouse 17 by outputting the mouse-clock signal 84 inputted from the keyboard/mouse controller 26. The mouse-clock signal 84 receives and outputs the activated protection-enable signal 86. However, the second buffer 90 makes the mouse not be operated by interrupting the mouse-clock signal 84. The result of the above operation is transmitted to the user input/output unit 30 through the system controller 40 and is then displayed.

If the serial port 18 is selected in the above selecting process, the security system controller 40 activates and outputs the protection-enable signal 94. The output signal 92 inputted from the serial port controller 28 is outputted as the transmit signal 96 through the third buffer 98. The output signal 92 receives and outputs the activated protection-enable signal 94. The third buffer 98 prevents data from being outputted to the serial port 18 by interrupting the output signal 92. The fourth buffer 102 outputs the receive signal 100 inputted from the serial port 18 to the serial port controller 28. The receive signal 100 receives and outputs the activated protection-enable signal 94. The fourth buffer 102 prevents data from being inputted to the serial port controller 28 by interrupting the receive signal 100. The result of the above operation is transmitted to the user input/output unit 30 through the system controller 40 and is then displayed.

As mentioned above, the present invention provides a security device for a digital computer system, orated under another operating system by using hardware, that protects a computer system while allowing it to interface in a normal state with an input/output device or a file.