JP5367684B2 - Computer with enhanced security and power control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a computer which can be securely protected from a software attack. <P>SOLUTION: When a start button 101 is pressed, a power-controller 31 can control a DC/DC converter 33 to supply power to each device of a computer. A switch 103 is OFF under a fixed condition. While the switch 103 is being OFF, the power-controller can supply the power only when authentication by a fingerprint authentication device 41 is successful. A third party who does not succeed in the fingerprint authentication cannot access a password input screen of BIOS. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a technique for enhancing the security of a computer, and more particularly, to a technique for reliably protecting user data from software attacks.

  Computers perform power-on authentication when powered on and booted to improve security against unauthorized access. In the power-on authentication, in order for only a genuine user registered in advance to use the computer, the BIOS starts the power-on password, supervisor password, and hard disk drive (HDD) password before the OS starts operating. Request a plurality of BIOS passwords. In the operating environment of the BIOS, the authentication process can be performed relatively safely because it is not connected to the network and other programs are not executed simultaneously.

  The invention of Patent Document 1 in which the inventor of the present invention is a joint inventor and is assigned to the applicant of the present invention uses a fingerprint authentication device to turn on the power of a computer and to the provisions of TCG (Trusted Computing Group). A technique for performing authentication of a physical presence based thereon is disclosed. This document describes that when fingerprint authentication is successful, a pseudo-press signal of an activation button is generated to start the computer, but when fingerprint authentication fails, activation is performed by pressing the activation button.

  Patent Document 2 discloses a technique for performing user authentication before starting an OS with either a password or biometric data. Patent Document 3 describes that biometric data authentication is used as the only authentication method for authentication at startup of a computer. In this document, when biometric data authentication is set as the only authentication method at startup, the system administrator can start the system if the system administrator is injured by a finger or the biometric data authentication device fails. It is described that there is a problem because it disappears.

  As a solution to this problem, this document provides a screen that does not allow password authentication for general users, while accepting both password-based authentication and biometric data authentication at startup. It is described that a password can be authenticated by a system administrator by preventing a decrease in the security level in authentication of a general user by providing a screen that can be authenticated.

JP 2010-146048 A JP 2002-2222022 A JP 2007-280216 A

  When the computer is turned on, the computer automatically executes the BIOS first, and displays the BIOS password input screen when the BIOS password is set. However, once the computer is under the control of a third party due to loss or theft, the BIOS password is subject to dictionary attacks or brute force attacks, or the password itself is a string that is easy to guess. Is at risk of being deciphered. If only a genuine user can turn on the computer, the level of security against software attacks can be maximized.

  Biometric authentication devices that use fingerprints and veins are more secure than passwords and can reduce the burden of storing complicated passwords for users, so notebook-type portable computers ( Some notebook PCs) employ a method of starting a computer based on the result of fingerprint authentication. In the invention of Patent Document 1, the computer is turned on on the condition that the authentication by the fingerprint authentication device is successful. However, since the power-on by the start button is permitted, the notebook PC is illegally acquired. A third party can easily reach the BIOS password input screen.

  In the inventions of Patent Documents 2 and 3, the fingerprint authentication device is used as an alternative method of password input required after power-on rather than power-on. In these inventions, the power can be turned on also by pressing the start button in parallel with the fingerprint authentication device. Although the inventions of Patent Documents 2 and 3 utilize the characteristic of biometric authentication that security is improved compared to passwords, third parties can still turn on the computer.

  In Patent Documents 1 to 3, the boot button can be operated when booting using the fingerprint authentication device. If the computer is booted only by the fingerprint authentication device, the finger of the registrant is injured. This is because the computer cannot be booted due to a change of the user or a failure of the apparatus. Further, even if the power can be turned on only by the fingerprint authentication device, it is necessary to adapt to the user who wants to start by pressing the start button. At this time, it is necessary to protect the user data accumulated so far so as not to lower the security level. Also, it is necessary to prevent the level of security from being lowered even when the biometric authentication device is illegally removed or fails.

  Accordingly, an object of the present invention is to provide a computer with enhanced security. A further object of the present invention is to provide a computer that can surely protect against software attacks. It is a further object of the present invention to provide a power control method and a computer power-on system for such a computer.

  The present invention provides a computer with enhanced security. When a new user starts using the computer, the computer transits to a mechanical off state in which all power is stopped. The computer is configured to automatically transition to the power-on state when a power source is connected in the mechanical-off state. When the computer automatically changes to the power-on state, the switch operation of the start button is invalidated, and thereafter, the computer changes to the soft-off state. After the transition to the soft-off state, the transition to the power-on state is made only by the output of the biometric authentication device that has been successfully authenticated. The activation button means any means that can turn on the computer other than the biometric authentication device.

  Therefore, since a user other than the user registered in the biometric authentication apparatus cannot turn on the computer, the possibility of receiving a software attack can be completely eliminated even if the computer is controlled by a third party. The switch operation of the start button can be invalidated safely in the BIOS boot process before the control is transferred to the OS. By setting the BIOS password before transitioning to the soft-off state, it is possible to ensure safety when the biometric authentication device is not turned on.

  In the present invention, since the authenticity of the person can be confirmed by biometric authentication, the boot process by the BIOS after the transition from the soft-off state to the power-on state can be completed without requiring the input of the BIOS password. When disabling the start button switch operation, the BIOS can display a start flag setting screen for enabling or disabling the start button switch operation. The user can set power-on by the start button and power-on by the biometric authentication device by setting a start flag.

  At this time, if the start flag setting screen is displayed only when the start flag is not set, once the start flag is set, the start button switch operation is always performed when the power is turned on from the mechanical off state. Disabled and transitions to soft-off state. In addition, when the start flag is set, the switch operation of the start button becomes invalid even in the soft-off state, so the third party cannot rewrite the start flag illegally because the power cannot be turned on either in the mechanical-off state or in the soft-off permanent state. I can't. By setting the start flag, after the transition from the mechanical-off state to the power-on state, the start button switch operation is disabled when the start flag is set, and the start button when the start flag is released It is possible to make the transition to the soft-off state after enabling the switch operation.

  In the present invention, setting the activation flag by the user is a manifestation of the intention to increase the security level of the computer. Therefore, if the activation button can be used to turn on the power after the activation flag is set, not only the genuine owner but also a third party can be realized, leading to a reduction in the security level. Therefore, when the activation flag is set, neither the power-on from the mechanical off state nor the power-on from the soft off state can be performed by the activation button.

  However, even after the activation flag is set once, there is a need to cancel the activation flag due to a change in the user, a failure of the biometric authentication device, or the like. In the present invention, focusing on the fact that the most important property to be protected by the computer is the user data, the computer can be released only when the user data is protected to prevent the security level from being lowered. The effective use of is enabled.

  In the present invention, when the power supply is automatically turned on from the mechanical off state when the storage device for storing user data is not connected, the start flag is released and then the soft off state is entered to start up. The button can be used. In addition, even when the power cannot be turned on from the biometric authentication device, when the power is automatically turned on from the mechanical-off state when the storage device is not connected, the activation flag is released and then the transition is made to the soft-off state. This makes it possible to use the start button.

  According to the present invention, a computer with enhanced security can be provided. Furthermore, according to the present invention, it is possible to provide a computer that can surely protect against software attacks. Furthermore, according to the present invention, it is possible to provide a method for controlling the power supply in such a computer and a computer power-on system.

It is a functional block diagram which shows the structure of the main hardware of a notebook PC. It is a figure explaining the power supply system of the DC / DC converter corresponding to each power state. It is a functional block diagram which shows the structure of a fingerprint authentication apparatus. It is a figure which shows the data structure of BIOS_ROM. It is a figure which shows the data structure of secure NVRAM. It is a functional block diagram which shows the structure of the hardware of a POA starting circuit. It is a flowchart explaining the procedure at the time of reset of POA starting. It is a flowchart explaining the procedure of the normal operation | movement of POA starting.

[Definition]
First, terms used in this specification are defined. Power-on authentication (POA) is a power-on password, supervisor password, or HDD password in which a BIOS to be executed first when a computer is shifted from a power-off state to a power-on state is preset. This means that the user's validity is authenticated by requesting the input of the BIOS password. In this embodiment, power-on authentication can be performed by authentication by a fingerprint authentication device. Turning on the power means that power is supplied to the devices constituting the computer to change the power state from the power off state to the power on state.

  Booting is a series of computer processes in which the BIOS is first executed when the computer is turned on, and then the operating system (OS) and other programs are loaded into the main memory to build the execution environment. Refers to processing. The boot includes a process performed by the BIOS first after the power is turned on and a process performed by the OS after the BIOS process is completed.

  Therefore, the operation and state are different from “power-on” in this specification and “computer startup” which means that the boot process at the BIOS stage or the complete boot process is completed. When the BIOS password is set, it is necessary to perform power-on authentication to complete the boot process at the BIOS stage. To perform power-on authentication, it is necessary to turn on the computer and execute the BIOS. is there.

  POA activation means that the computer is turned on by the biometric authentication device, and even if a BIOS password is set, the BIOS boot process is completed without inputting the BIOS password. The BIOS password is a password requested by the BIOS, and includes a power-on password, a supervisor password, and an HDD password. The power-on password is a password set in the system in order to proceed with the boot process at the BIOS stage when the computer is turned on. The supervisor password is a password set in the system in order to change the BIOS setting. The HDD password is a password set in the HDD in order to restrict access to the HDD.

[Overall hardware configuration]
FIG. 1 is a functional block diagram showing a main hardware configuration of the notebook PC 10. The CPU 11 is an arithmetic processing unit having a central function of the notebook PC 10 and executes an OS, a BIOS, a device driver, an application program, or the like. The north bridge 13 is connected to the main memory 15, the video controller 17, and the south bridge 21, and has a memory controller function for controlling an access operation to the main memory 15, and between the CPU 11 and other devices. Includes a data buffer function to absorb the difference in data transfer speed.

  The video controller 17 includes a graphic accelerator and a VRAM, receives a drawing command from the CPU 11, generates an image to be drawn, writes the image to the VRAM, and sends the image read from the VRAM to the LCD 19 as drawing data. The main memory 15 is a random access memory used as a reading area for a program executed by the CPU 11 and a work area for writing processing data. The south bridge 21 has interface functions of various standards, and various input / output devices are connected thereto. In FIG. 1, an HDD 23 is connected to the south bridge 21 as an example. The south bridge 21 includes a register that stores the power state of the notebook PC 10.

  The HDD 23 stores a well-known program such as an OS, a device driver, an application program, and user data. User data is data to be protected in the notebook PC 10, and the notebook PC 10 adopts POA activation to improve the security level, thereby strengthening the protection of user data stored in the HDD 23. The HDD 23 is an example of a storage device that stores user data, and only the program can be stored in the HDD 23 and user data can be stored in another storage device.

  The south bridge 21 is connected to a legacy device conventionally used in the notebook PC 10 or a device that does not require high-speed data transfer via the PCI bus or the LPC bus 25. Connected to the LPC bus 25 are a security chip (TPM: Trusted Platform Module) 26, a BIOS_ROM 27, an embedded controller (EC) 29, and a secure NVRAM 43 based on specifications defined by an industry group called TCG.

  The BIOS_ROM 27 and the secure NVRAM 43 will be described later with reference to FIGS. The EC 29 is a microcomputer composed of an 8 to 16 bit CPU, ROM, RAM, and the like, and further includes a multi-channel A / D input terminal, a D / A output terminal, a timer, and a digital input / output terminal. Yes. The EC 29 can execute a program for managing the power supply and temperature of the notebook PC 10 independently of the CPU 11. The EC 29 includes a keyboard / mouse controller, to which a keyboard / mouse 45 is connected.

  The power controller 31 is a wired logic digital control circuit (ASIC) that is connected to the EC 29, the fingerprint authentication device 41 and the DC / DC converter 33 and controls the DC / DC converter 33 based on an instruction from the EC 29. The DC / DC converter 33 converts the DC voltage supplied from the AC / DC adapter 39 or the battery pack 35 into a plurality of voltages necessary for operating the notebook PC 10, and is further defined according to the power state. Power is supplied to each device based on the power supply category. The relationship between the power state and the power supply section will be described later with reference to FIG. When connected to the notebook PC 10, the AC / DC adapter 39 supplies power to the charger 37 that charges the battery pack 35 and the DC / DC converter 33.

  The notebook PC 10 conforms to the ACPI (Advanced Configuration and Power Interface) standard, and can transition to four global system states of G0 state, G1 state, G2 state, and G3 state. The G0 state corresponds to a S0 state (power-on state) as a power state, and the CPU 11 is in a state where an application program can be executed, and power is supplied to all devices. At this time, each device can perform a power saving operation according to the device power state from the D0 state to the S3 state based on the unique function.

  The G1 state is also called a sleeping state, and includes four sleeping states from the S1 state to the S4 state. In the notebook PC 10, an S3 state and an S4 state are defined. The S3 state is also referred to as a suspend state or a standby state, and stops power to devices other than those necessary for holding the storage of the main memory 15. However, power may be supplied to a minimum number of devices that are not directly related to the storage of the main memory 15 in the suspended state. In the suspended state, power supply to the CPU 11 and system clock supply are stopped.

  The S4 state is also called a hibernation state or a hibernation state. The context of the CPU 11 and the data stored in the main memory 15 are stored in the HDD 23, and most devices are powered off. In the hibernation state, the storage holding operation of the main memory 15 is stopped. The G2 state corresponds to the S5 state as a power state, which is also called a soft-off state, and most devices are powered off. The G3 state is also referred to as the mechanical off state, and all the power supply is stopped and standby power is consumed except for the button battery that supplies power to the RTC (Real Time Clock) by removing the battery pack 35 and the AC / DC adapter 39. The state that does not. The S4 state, the S5 state, and the G3 state are called power-off states.

  Transition from the power-off state to the power-on state is called cold start or cold boot, and transition from the suspend state to the power-on state is called warm start or warm boot. FIG. 2 is a diagram for explaining the power supply system of the DC / DC converter 33 corresponding to each power state. In the notebook PC 10, an S0 state, an S3 state, an S4 state, an S5 (AC) state, and an S5 (DC) state are defined. However, a computer that supports the S1 state and the S2 state is also included in the scope of the present invention.

  The S5 (AC) state means a power-off state in which the AC / DC adapter 39 is connected, and the S5 (DC) state is a power state in which the AC / DC adapter 39 is removed and the battery pack 35 is attached. It means the off state. In the following description, unless otherwise noted, the term “soft-off state” includes both the S5 (AC) state and the S5 (DC) state.

  In the S5 (DC) state, power is supplied only to the minimum devices necessary to start up the power supply of the notebook PC 10 in order to minimize battery consumption in the power-off state. The DC / DC converter 33 is configured to be able to supply power with four power supply systems from the VCC1 system to the VCC4 system. In the mechanical off state, power is not supplied from any power supply system.

  The VCC1 system is required to operate in any power state except the G3 state, the power controller 31, the fingerprint authentication device 41, a lid sensor (not shown) for detecting the state in which the LCD 19 is opened, and Power is supplied only to a minimal number of devices, such as those in the South Bridge 21 that are involved in powering up.

  The VCC2 system supplies power to the EC 29, the fingerprint authentication device 41, the south bridge 21, and the like that operate in each power state except the G3 state and the S5 (DC) state. The fingerprint authentication device 41 controls the operation of the DC / DC converter 33 so that power is supplied from the VCC1 system when in a standby state, and power is supplied from the VCC2 system when performing actual authentication processing by swiping a finger. The power system is switched inside the fingerprint authentication device 41. The VCC3 system supplies power to the main memory 15 and the north bridge 13 that operate in the S0 state and the S3 state. The VCC4 system supplies power to the CPU 11, LCD 19, HDD 23, and the like that operate in the S0 state.

  The VCC1 system is composed of a linear regulator that is simple in configuration and excellent in efficiency at light loads. The linear regulator controls the resistance value of the variable resistance element to maintain the output voltage within a predetermined range. However, since the efficiency decreases as the load increases, it is suitable for a power source with a small load. A state in which the notebook PC 10 in the mechanical off state is supplied with power from at least one of the battery pack 35 and the AC / DC adapter 39 is referred to as a power supply reset.

  The VCC2 system to the VCC4 system are composed of switching regulators that are complex in configuration but excellent in efficiency at high loads. The switching regulator maintains the output voltage within a predetermined range by controlling the duty ratio of the switching element. Since the switching regulator generates a switching loss even at a light load, the switching regulator is less efficient than the linear regulator for a small load such as the VCC1 system. In addition, since the range of devices to which power is supplied is the same in the S4 state and the S5 (AC) state, the S4 state can be handled as a part of the S5 state.

  Returning to FIG. 1, the EC 29 controls the DC / DC converter 33 via the power controller 31 and operates a necessary power supply system according to the power state defined in FIG. 2. The fingerprint authentication device 41 is connected to the power controller 31, the fingerprint sensor 42 and the south bridge 21. The fingerprint sensor 42 is a swipe fingerprint sensor and generates a fingerprint image of the user. Each of the fingerprint authentication device 41 and the fingerprint sensor 42 is attached so as to be physically integrated with the casing of the notebook PC 10. However, the fingerprint authentication device 41 and the fingerprint sensor 42 are not necessarily fixed to the housing, and may be arranged in a range where a user who directly controls the notebook PC 10 can perform authentication.

[Configuration of fingerprint authentication device]
FIG. 3 is a functional block diagram showing the configuration of the fingerprint authentication device 41 for starting POA. The feature extraction unit 83 extracts a feature point by converting the fingerprint image received from the fingerprint sensor 42 into a core line, and further creates a collation fingerprint data by quantifying the correlation between the extracted feature points. The fingerprint sensor 42 is provided with a proximity sensor 82 that detects that a finger is placed on the fingerprint sensor 42 during a swipe due to a change in electric field or capacitance. The template storage unit 87 stores authentic user verification fingerprint data registered in advance as a template. The verification unit 85 compares the verification fingerprint data generated by the fingerprint sensor 42 and the feature extraction unit 83 with the template for authentication, and determines that the authentication is successful when the matching point exceeds a predetermined score.

  The data storage unit 91 receives the data for authenticating the physical ownership presence by the fingerprint authentication device 41 and the power-on password, supervisor password, and HDD password for single sign-on by the fingerprint authentication device 41. It is a secure non-volatile memory to store. In order to rewrite the data stored in the data storage unit 91, the user needs to be authenticated by the fingerprint authentication device 41 or authenticated by the supervisor password before the OS starts operating.

  The input / output control unit 89 controls data transfer with the outside through the south bridge 21 and accesses the data storage unit 91. Further, the input / output control unit 89 outputs a pseudo activation signal corresponding to the activation signal when the activation button 101 (see FIG. 6) is pressed when the fingerprint authentication by the collation unit 85 is successful, to the activation signal line 107 (see FIG. 6). ) The power supply unit 84 receives power from the VCC1 system and the VCC2 system of the DC / DC converter 33, and supplies power to the internal device of the fingerprint authentication apparatus 41 and the fingerprint sensor.

  Since the fingerprint authentication device 41 operates in an idle mode that consumes less power until the finger is swiped for fingerprint authentication, the power controller 31 is configured to send power from the VCC1 system to the power supply unit 84. To control. When the finger is set on the fingerprint sensor 42 and it is necessary to operate in the authentication mode, the input / output control unit 89 switches the power from the VCC1 system to the VCC2 system when the proximity sensor 82 detects the approach of the finger. Send a signal for. In this way, the fingerprint authentication device 41 operates so as to reduce power consumption in the power-off state.

[Configuration of BIOS_ROM 27]
FIG. 4 is a diagram illustrating a data configuration of the BIOS_ROM 27. The BIOS_ROM 27 is a non-volatile memory in which stored contents can be electrically rewritten, and adopts a boot block method in order to reduce a risk associated with rewriting. The boot block 27a is a write-protected storage area, and the code stored here is treated as a CRTM (Core Root of Trust for Measurement) code 130 defined in the TPM specification, and rewritten without special authority. Can not be. The CRTM code 130 is configured as a consistent part of the platform initialization code and must always be executed first when the platform is reset.

  The CRTM code 130 is executed entirely when the notebook PC 10 is cold booted, but only the code related to the storage maintenance of the main memory is executed when the notebook PC 10 is warm booted. All consistency measurements for the laptop PC 10 platform are made based on this CRTM code 130. In the boot block 27a, a POA activation code 131, a CRTM authentication code 133, a POST code 135, and an I / O code 137 are stored as a CRTM code 130.

  The POA activation code 131 is a code for performing processing necessary for POA activation by the fingerprint authentication device 41. The CRTM authentication code 133 is a code for performing physical presence authentication using the fingerprint authentication device 41 and includes a code for rewriting the BIOS_ROM 27. A POST (Power-On Self Test) code 135 is a code for inspecting, setting, and initializing hardware. The I / O code 137 is a code for accessing the hardware under the BIOS operating environment.

  The system block 27b stores a utility code 139 and a password authentication code 141 that perform BIOS functions that are not executed by the code stored in the boot block 27a. The consistency of the code stored in the system block 27b is calculated based on the CRTM code 130 stored in the boot block 27a. The utility code 139 is a code for controlling the power source, the temperature in the housing, and the like. The password authentication code 141 is a code for authenticating the power-on password, the supervisor password, and the HDD password. The BIOS code stored in the BIOS_ROM 27 is executed by the CPU 11.

[Configuration of secure NVRAM]
FIG. 5 is a diagram showing a data configuration of the secure NVRAM 43. The secure NVRAM 43 is a non-volatile memory whose access is restricted under the OS environment. The secure NVRAM 43 stores a POA activation flag 151, an HDD identifier 153, a power-on password 155, and a supervisor password 157. The POA activation flag 151 is a flag that enables POA activation and is written by the POA activation code 121. The HDD identifier 153 is binding data for confirming whether the POA activation code 131 is the one in which the HDD 23 is first registered or is exchanged thereafter.

[POA start-up circuit]
FIG. 6 is a functional block diagram showing a hardware configuration of the POA activation circuit 100 for performing POA activation by the fingerprint authentication device 41. The power controller 31 includes a PB control circuit 113, a DC / DC control circuit 115, and a state register 117. The state register 117 is set as a power state after the transition when the power state of the notebook PC 10 transitions from the power-on state (S0) to the hibernation state (S4) or the soft-off state (S5). Set by the South Bridge 21. The state register 117 is reset when the power supply of the VCC1 system is stopped due to the transition to the mechanical off state (G3). Therefore, the state register 117 can store one of a mechanical off state (G3), a hibernation state (S4), and a soft off state (S5).

  The PB control circuit 113 controls the operation of the switches 103 and 105 in order to validate or invalidate the switch operation of the start button 101 and the function key (Fn key) 45a according to the instruction of the EC 29. The DC / DC control circuit 115 controls the power supply from the VCC1 system to the VCC4 system of the DC / DC converter 33 according to the instruction of the EC 29 in accordance with the power state. The DC / DC control circuit 115 is configured to automatically supply power from the VCC1 system to the VCC4 system when the power of the notebook PC 10 is reset. The POA activation code 131 controls the PB control circuit 113 and the DC / DC control circuit 115 through the EC 29.

  The start button 101 is attached to the casing of the notebook PC 10 so as to be physically integrated. The start button 101 is connected to a DC / DC control circuit 115 via a switch 103 and a start signal line 107. The Fn key 45 a forms part of the keyboard / mouse 43 and is connected to the EC 29 via the switch 105.

  The switches 103 and 105 are N-channel MOS_FETs. The gates of the switches 103 and 105 are connected to the PB control circuit 113 through a switch control line 109. The switch control line 109 is connected to the ground by a pull-down resistor, and when no voltage is applied to the switch control line 109, the switches 103 and 105 are surely turned off. The fingerprint authentication device 41 is connected to the DC / DC control circuit 115 of the power controller 31 via the activation signal line 107.

  When power is supplied to the VCC1 system and the user presses the start button 101 when the switch 103 is on, a start event is sent from the power controller 31 to the south bridge 21 by a signal sent through the start signal line 107. Then, a start signal is sent from the south bridge 21 to the DC / DC control circuit 115. The DC / DC control circuit 115 that has received the activation signal controls the operation of the DC / DC converter 33 in order to shift the notebook PC 10 to the power-on state. When the start button 101 is pressed, a cold boot or a warm boot is possible.

  When the user presses the Fn key 45a when the switch 105 is on, a start event is sent from the EC 29 to the south bridge 21 by a signal sent through the start signal line 111, and the DC / DC control circuit is sent from the south bridge 21. An activation signal is sent to 115. When the Fn key 45a is pressed while the switch 105 is on, warm boot from the suspended state (S3) is possible. Even when a warm boot is performed, a part of the POST code 135 is executed. Therefore, when the POA is activated, the Fn key 45a is also disabled to further enhance the security.

  In order to perform POA activation, the fingerprint authentication device 41 needs to be the only device that powers on the notebook PC 10 except when the security of user data stored in the HDD 23 is reliable. Therefore, once the POA activation flag 151 is set, the POA activation circuit 100 turns off the switches 103 and 105 and invalidates the activation button 101 and the Fn key 45a. The notebook PC 10 can be turned on only by the fingerprint authentication device 41. The fingerprint authentication device 41 sends a pseudo activation signal to the activation signal line 107 when the fingerprint authentication is successful. The DC / DC control circuit 115 treats the pseudo activation signal in the same manner as the activation signal generated by the activation button 101 and controls the operation of the DC / DC converter 33.

  FIGS. 1 to 5 simply illustrate the main hardware configuration and connection relations related to the present embodiment in order to describe the present embodiment. In addition to those mentioned in the above description, many devices are used to configure the notebook PC 10. However, they are well known to those skilled in the art and will not be described in detail here. Within a range that can be arbitrarily selected by those skilled in the art, a plurality of blocks may be configured as one integrated circuit or device, or conversely, a single block may be divided into a plurality of integrated circuits or devices. Is included in the scope of the present invention.

  In addition, the types of buses and interfaces connecting the devices are not particularly limited to the present invention, and the present invention is within the scope that can be arbitrarily selected by those skilled in the art even for other connections. Included in the range. Furthermore, the circuit for switching the activation operation of the start button 101 and the Fn key 45a between valid and invalid in FIG. 6 is an example. For example, the circuit is configured by only EC 29 or the function sharing between the EC 29 and the power controller 31 is changed. In the range that can be arbitrarily selected by those skilled in the art, it is included in the scope of the present invention.

[How to start POA]
Next, an operation procedure when the notebook PC 10 starts POA will be described with reference to flowcharts of FIGS. FIG. 7 shows a POA activation procedure when the power is reset, and FIG. 8 shows a POA activation procedure in a normal operation after the power is reset. The POA activation is performed by the POA activation circuit 100 and the BIOS code shown in FIG. In block 201 of FIG. 7, it is assumed that the user uses the notebook PC 10 for the first time, and the battery pack 35 is not attached and the AC / DC adapter 39 is not connected.

  Therefore, the notebook PC 10 has transitioned to the mechanical off state (G3). In the mechanical off state, the power supply of the VCC1 system is stopped, and the switches 103 and 105 are off because the PB control circuit 113 does not apply a voltage to the switch control line 109. In block 203, power is supplied to the notebook PC 10 from either the battery pack 35 or the AC / DC adapter 39, and the power supply is reset. In block 205, the state register 117 is reset to indicate a mechanical off state. 8, the south bridge 21 sets the state register 117 in the hibernation state (S4) or the soft-off state (S5) through the EC 29.

  In block 207, when power is supplied to the VCC1 system, the DC / DC control circuit 115 automatically supplies power from the VCC2 system to the VCC4 system to shift the notebook PC 10 to the power-on state. When transitioning to the power-on state, the CRTM code 130 first stored in the BIOS_ROM 27 is always executed by the CPU 11 and the BIOS boot process is started. The POA activation code 131 controls the operation of the PB control circuit 113 and the DC / DC control circuit 115 through the EC 29 and reads the contents of the state register 117 during the boot process, and executes the following procedure. In block 209, the POA activation code 131 determines whether the state register 117 indicates a mechanical off state.

  When the POA activation code 131 determines that the state register 117 indicates the mechanical off state, the POA activation code 131 proceeds to block 213, and when it determines that the state register 117 indicates the hibernation state (S4) or the soft off state (S5), FIG. Block 315 or 333. In block 213, the identifier of the HDD 23 acquired by the POST code 135 is compared with the HDD identifier 153 in which the POA activation code 131 is stored in the NVRAM 43, and it is determined whether or not the HDD 23 registered is attached to the notebook PC 10. To do.

  The significance of the HDD 23 here is in a storage device storing user data to be protected, and when storing user data in a second storage device different from the OS or application program, the second storage is used. Determine whether the device is connected. If it is determined that an HDD is installed, the process proceeds to block 215. If it is determined that an HDD is not installed or an unregistered HDD is installed, the process proceeds to block 251.

  In block 215, the POA activation code 131 refers to the NVRAM 43 to determine whether or not the POA activation flag 151 is set. If the block 319 or the block 335 in FIG. 8 is shifted to the block 215, the POA activation flag 151 may be set in the NVRAM 43 in the block 225. If the POA activation flag 151 is set, the process proceeds to block 217, and if not set, the process proceeds to block 221.

  In block 217, the POA activation code 131 does not instruct the PB control circuit 113 through the EC 29, the switches 103 and 105 are kept off, and the activation operation of the activation button 101 and the Fn key 45a is maintained in an invalid state. In block 220, the POA activation code 131 automatically shifts the notebook PC 10 to the hibernation state (S4) or the soft-off state (S5) without any user operation.

  If the block 319 or the block 335 in FIG. 8 has been shifted to the block 215, the supervisor password 157 may be set in the NVRAM 43 in the block 219. In block 221, if the supervisor password 157 is set, the password authentication code 141 displays an input screen for the supervisor password 157 on the LCD 19. When the user inputs the same character string as the supervisor password 157 registered in the NVRAM 43 at block 223, the POA activation code 131 displays a setting screen for the POA activation flag 151 on the LCD 19 at block 225. At this time, a screen for registering collation fingerprint data of the user who uses the notebook PC 10 is displayed on the LCD 19 to request registration for the fingerprint authentication device 41. If the supervisor password is not set at block 221, the process proceeds to block 219 and then to block 220.

  In block 219, the password authentication code 141 displays a setting screen for the supervisor password 157, the power-on password 155, and the HDD password on the LCD 19. Whether or not to input the BIOS password in block 219 is up to the user, but it is desirable to set the supervisor password 157 in case a situation where POA activation cannot occur occurs. As long as the HDD 23 is attached to the notebook PC 10, the third party cannot access the HDD 23 unless the authentication by the fingerprint authentication device 41 is successful, so the user data is safe, but when the HDD 23 is removed from the notebook PC 10. It is desirable to set an HDD password for safety. When the user inputs the HDD password, the password authentication code 141 writes it in the secure storage area of the HDD 23.

  If the user does not input the correct supervisor password 157 in block 223, the process moves to block 220. After that, the power to the notebook PC 10 can be turned on only by resetting the power in the block 203. If the user sets the POA activation flag 151 in block 225, the process proceeds to block 217. If not set, the process proceeds to block 227. In block 227, the POA activation code 131 instructs the PB control circuit 113 to apply a voltage to the switch control line 109 through the EC 29. As a result, the switches 103 and 105 are turned on, the switch operation of the start button 101 and the Fn key 45 is enabled, and the process proceeds to block 220.

  In block 251, when the password authentication code 141 refers to the NVRAM 43 and determines that the supervisor password 157 is set, the supervisor password 157 input screen is displayed on the LCD 19 and the process proceeds to block 253. If the password authentication code 141 determines in block 221 that the supervisor password 157 is not set, the process proceeds to block 219. Unless the supervisor password 157 is set in block 219, the process does not proceed to block 255. Therefore, it is not possible to automatically turn on the power from the mechanical off state to enable the switch operation of the start button 101.

  If the user inputs the same character string as the supervisor password 157 registered in the NVRAM 43 at block 253, the POA activation code 131 cancels the POA activation flag 151 of the NVRAM 43 at block 255 and moves to block 257. In block 257, the POA activation code 131 controls the PB control circuit 113 through the EC 29 to turn on the switches 103 and 105, and the process proceeds to block 220. As a result, the switch operation of the start button 101 and the Fn key 43a becomes valid. If the user does not enter the correct supervisor password 157 at block 253, the user cannot turn on the notebook PC 10 unless it is brought into the factory.

  Next, a procedure for starting the notebook PC 10 that has transitioned to the hibernation state (S4) or the soft-off state (S5) will be described with reference to FIG. The block 301 is always transferred after passing through the block 221. Therefore, the switch operation of the start button 101 becomes invalid when the POA activation flag 151 is set, and becomes valid when it is released.

  A block 303 indicates that the procedure is divided depending on whether or not the fingerprint authentication device 303 is present when the notebook PC 10 is not activated. Since the fingerprint authentication device 41 is normally incorporated in the casing of the notebook PC 10 and is not separated, it may be removed by some illegal action. Further, the case where the authentication operation is not normally performed corresponds to the case where the fingerprint authentication device 41 does not exist. If the fingerprint authentication device 41 does not exist, the process proceeds to block 305, and if it exists, the process proceeds to block 331.

  In block 331, the user swipes his finger on the fingerprint sensor. When the fingerprint authentication device 41 authenticates the user, it sends a pseudo activation signal to the DC / DC control circuit 115. At this time, the switch operation of the start button 101 may be valid or invalid. When the switch operation of the start button 101 is valid via the block 257, the HDD 23 is not attached, so there is no substantial meaning in turning on the power. When the switch operation of the activation button 101 is valid via the block 227, the POA activation flag 151 is canceled by the user's intention, so even if the power-on by pressing the activation button 101 is permitted. There are no security issues.

  In block 333, the password authentication code 141 ends the power-on authentication without requesting the password even if the power-on password 155 and the HDD password are set in block 219. When the boot process by the BIOS and the boot process by the OS are completed and the computer is completely booted up, and then the operation is completed, the power supply transitions to the hibernation state (S4) or the soft-off state (S5) in block 335. At this time, the south bridge 21 stores the power state after transition to the state register 117 through the EC 29.

  Furthermore, the battery pack 35 and the AC / DC adapter 39 may be removed and the state may change to the mechanical off state (G3). Thereafter, the process proceeds to block 203 to reset the power supply and automatically turn on the power, or the process proceeds to block 209 to return to the block 331 from the hibernation state (S4) or soft-off state (S5) and turn the power on. Can be thrown in.

  A block 305 indicates whether the switch operation of the activation button 101 is valid or invalid. When the switch operation of the start button 101 is valid, the user proceeds to block 311 and when invalid, the user proceeds to block 307 and operates. The switch operation of the start button 101 is valid when it passes through blocks 257 and 227 in FIG. 7, and the switch operation of the start button 101 is invalid when it passes via block 217. Whether the switch operation of the start button 101 is valid or invalid can be confirmed by the user pressing the start button 101.

  If the switch operation of the start button 101 is invalid, the user determines in block 307 whether or not the HDD 23 is attached to the notebook PC 10. When the HDD 23 is attached to the notebook PC 10, there is no method for starting the notebook PC 10 because the process proceeds to block 309. That is, even if the power is reset in block 203 of FIG. 7, the process returns to block 307 via blocks 213, 215, and 217. On the other hand, when the HDD 23 is removed, the power can be turned on by enabling the switch operation of the start button 101 in the block 257 by resetting the power from the block 203 in FIG. .

  In block 311, a new HDD can be attached to the notebook PC 10 through the block 257. In block 313, the user presses the start button 101 to turn on the power. When the POST code 135 recognizes a new HDD attached to the notebook PC 10, it registers the HDD identifier 153 in the NVRAM 43. Further, the password authentication code 141 prompts the user to register by displaying an HDD password input screen on the LCD 19, but the user is free to register or not. Thereafter, the boot is completely completed at block 317, and the power-off state is entered at block 319. Thereafter, the state register 117 is set in the same procedure as in the block 335, and the power can be turned on.

  Next, features of security by starting the POA of the notebook PC 10 will be described. When the notebook PC 10 is shipped from the factory, the activation button 101 is always disabled (block 203). When the user first turns on the power supply by attaching the battery pack 35 and / or connecting the AC / DC adapter, it automatically starts and always transitions to the hibernation state or the soft-off state after completing the procedure shown in FIG. To do. Until the hibernation or soft-off state is reached, the user can enable POA activation by setting the POA activation flag (block 225).

  In normal usage of the notebook PC 10, the power state transitions between the hibernation state or the soft-off state and the power-on state. Once the POA activation flag 151 is set, the switch operation of the activation button 101 becomes invalid, and it can be activated only by the fingerprint sensor in a normal usage (block 331). Therefore, only a genuine user registered in the fingerprint sensor can turn on the power, and the third party can start the boot process at the BIOS stage to reach the input state of the BIOS password and perform a software attack. Security is strengthened because it is impossible.

  At this time, even if a power-on password is set, the notebook PC 10 regards that power-on authentication has been performed without requiring the user to input the power-on password, and completes the boot process by the BIOS. Even if the power-on password is not input, since it is authenticated that the power is turned on by the fingerprint authentication device 41 as a genuine user, the security level is not lowered, and the user must remember the password. Also disappear.

  If the user does not set the POA activation flag until the hibernation state or the soft-off state is reached, the switch operation of the activation button 101 becomes valid as in the conventional case (block 227). In this case, the security of the BIOS password is equivalent to the conventional one, but the convenience can be improved because the user can turn on the power with either the fingerprint authentication device 41 or the activation button 101.

  When resetting the power supply, the POA activation flag 151 can be set by deciding whether to enhance the security by going through the procedure of FIG. Here, after setting the POA activation flag 151, another user may want to use the notebook PC 10. At this time, to release the POA activation flag 151, it is necessary to power on the notebook PC 10. However, it is necessary to prevent the enhanced security level from being lowered by making the fingerprint authentication device 41 the only power-on means upon power-on.

  In this embodiment, when the HDD 23 is not attached when the power is turned on from the mechanical off state, the POA activation flag 151 is canceled by inputting the supervisor password, and the activation of the activation button 101 is enabled. (Block 257). The HDD 23 stores user data to be protected. If the HDD 23 is not attached, there is no possibility of access to the user data. Can be maintained.

  Even if the fingerprint authentication device 41 fails or is removed after the POA activation flag 151 is set, the notebook PC 10 needs to be usable. Similarly, when the power is turned on from the mechanical off state, the HDD 23 is attached. If not, the activation flag 151 is canceled (blocks 255 and 307). Although there is a risk that the HDD 29 removed from the notebook PC 10 is attached to another computer and the user data is wiretapped, the HDD 29 is prohibited from being accessed from a computer other than the registered computer in addition to the HDD password. Various technologies have been introduced. The POA activation in the present invention can be performed using a biometric authentication device using other biometric information such as a palm, retina, iris, voice, or vein instead of the fingerprint authentication device 41.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

27 ... BIOS_ROM
31 ... Power controller 43 ... Secure NVRAM
100 ... POA activation circuit 101 ... activation button

Claims (16)

A method for a computer to control power,
Automatically transitioning to a power-on state when a power source is connected to the computer in a mechanical-off state;
The computer invalidates the switch operation of the start button when automatically transitioning to the power-on state;
Transitioning the computer to a soft-off state with the switch operation disabled;
A biometric authentication device authenticating while transitioning to the soft-off state;
Transitioning from the soft-off state to the power-on state in response to successful authentication by the biometric authentication device.   2. The step of causing the computer to realize a function of completing a boot process after transitioning from the soft-off state to the power-on state without requesting input of a BIOS password. Method.   The step of disabling the switch operation of the start button includes the step of causing the computer to realize a function for displaying a setting screen of a start flag for enabling or disabling the switch operation of the start button. Or the method of claim 2.   4. The method according to claim 3, wherein the activation flag setting screen is displayed only when the activation flag is not set.   After the transition from the mechanical-off state to the power-on state, the activation button is disabled when the activation flag is set, and the activation button when the activation flag is released 5. The method according to claim 3 or 4, further comprising the step of causing the computer to realize a function for automatically transitioning to the soft-off state after enabling the switch operation. Causing the computer to realize a function of determining whether or not a storage device for storing user data is connected;
The BIOS has a function of canceling the start flag and transitioning to the soft-off state when the storage device is not connected and the power-off state is automatically transitioned from the mechanical-off state. 6. A method according to any one of claims 3 to 5, comprising the steps of causing a computer to implement.   The BIOS has a function of canceling the activation flag and transitioning to the soft-off state when the mechanical-off state is automatically transitioned to the power-on state in a state where authentication by the biometric authentication device cannot be performed. The method of claim 6, comprising causing the computer to implement.   The method according to claim 1, wherein the soft-off state includes a hibernation state. A computer capable of transitioning from a soft-off state to a power-on state,
A power controller for controlling the power of the computer;
An activation button for sending an activation signal to the power controller by a switch operation to transition from the soft-off state to the power-on state;
A switch control circuit for controlling the activation signal generated by the activation button to be valid or invalid;
A biometric authentication device that sends a pseudo activation signal to the power controller while the switch control circuit invalidates the activation signal to transition from the soft-off state to the power-on state;
A storage device for storing an activation flag set so as to invalidate the switch operation of the activation button,
The power controller is configured to automatically supply power to the computer when a power source is connected in a mechanical off state, and the computer is automatically supplied with the startup flag cleared. A computer that transitions to a power-off state after displaying a screen for setting the startup flag . 10. The computer according to claim 9 , wherein the computer to which power is automatically supplied in the mechanical off state invalidates the start signal and transitions to the power off state when the start flag is set. Computer. Automatically when the said computer to which power is supplied to the start flag is cleared, claim 9 or claim transitions to the power-off state after enabling said activation signal by the mechanical off state The computer according to 10 . Automatically when power is supplied by the mechanical-off state, one of claims 9, wherein the start flag is cleared when the storage device storing the user data is not attached to the computer of claim 11 A computer according to the above. The computer according to any one of claims 9 to 12 , wherein the switch control circuit performs a function for invalidating the activation signal in a BIOS boot process. A computer power-on system,
A processor;
Operating means for generating a start signal by operating a switch and supplying power to the processor;
Switch control means for setting the switch operation to be valid or invalid;
Biometric authentication means capable of generating a pseudo activation signal and supplying power to the processor in a state where the switch operation is disabled,
Power on to automatically supply power to the processor when a power supply is connected in a mechanical off state, and to stop power to the processor in a state where the switch control means is set to enable or disable the switch operation system. The power is automatically supplied to the processor when a power source is connected in a mechanical off state, and the switch control means performs the switch operation when a storage means for storing user data is not connected to the computer. The power-on system according to claim 14 , wherein the power to the processor is stopped after being set to be valid. The power is automatically supplied to the processor when a power source is connected in a mechanical off state, and the switch control unit sets the switch operation to be effective when the biometric authentication unit cannot generate the pseudo activation signal. The power-on system according to claim 15 , wherein power to the processor is stopped after a while.

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