Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F21/70—Protecting specific internal or peripheral components, in which the protection of a component leads to protection of the entire computer
  • G06F21/82—Protecting input, output or interconnection devices
  • G06F21/83—Protecting input, output or interconnection devices input devices, e.g. keyboards, mice or controllers thereof
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
  • G06F21/30—Authentication, i.e. establishing the identity or authorisation of security principals
  • G06F21/31—User authentication

Definitions

• the present invention relates to a method for protecting an electronic computer having a keyboard and a display unit, comprising the stages to stroke one or more predetermined keys of the keyboard to activate the blocking of the same and to stroke on the keyboard a determined password, or a combination of keys, to unblock the keyboard and restore its use.
• the present invention relates to a method for protecting a personal computer use by part of a not enabled user by selecting of the peripheral units, connected to the computer, to be protected or locked.
• BACKGROUND ART From the USA invention N. 5.097.506 a method is known in which the protection of a personal computer keyboard use is realized by way of the stroking of a determined key combination for the blocking, and of a password for the subsequent unblocking of the same keyboard.
• Such a method which is independent from the operating system, foresees that, after the stroking of the determined keys combination, the keyboard controller logic circuitry activates a blocking situation of the same keyboard functionality till the stroking of the password, that is the predefined sequence of keys that, interpreted by the keyboard controller, is capable of re-enabling the regular operation of the keyboard.
• Such a method has the disadvantage of not displaying on the personal computer display any message concerning the keyboard blocking and the subsequent enquiry of the password stroking, so that the user, if unintentionally stroked the keyboard blocking combination, finds the keyboard blocked against his will, without knowing the reason of it and without knowing the way to come out from the blocking situation. Moreover the user is not able to verify neither if he is stroking or has stroked the correct password, nor how many keys he has already stroked. Usually the unpleasant consequence of it, is that he needs to stroke that password many times in order to re-enable the keyboard regular operation.
• Object of the present invention is to realize a keyboard protection method that, independently from the operating system used by the computer, allows the user to know, clearly by way of the display of suitable help directions on the display, either if the keyboard is blocked owing to the blocking combination stroking, or how many keys he stroked to compose the password required to unblock the keyboard, and that at the same time allows to carry out such operations without modifying the usual flux of the personal computer activities.
• the stroking of one or more predetermined keys is capable of causing the display, on the display unit, of a message requiring the user to stroke a password, either for operationalizing the keyboard blocking or to unblock the same keyboard if it is in a blocking condition.
• Fig. 1 is a perspective and schematic view of a portable personal computer which uses the method according to the present invention.
• Fig. 2 is a logic operation diagram of the personal computer of Fig. 1
• the protecting method according to the present invention is disclosed as applied on a personal computer 10 comprising a keyboard 13 and a display 12 on which, in addition to the routine or commonly known information or messages 14, can appear messages 14 requiring a password to the user.
• the personal computer 10 comprises also a central processing unit (CPU) 21 to which are connected, in a known manner, as well as the display 12, a reading only memory (ROM) 22, a random access memory (RAM) 23, a reading and writing non volatile memory (CMOS RAM) 24 and a random access context memory (SMRAM) 25.
• the CPU 21 is of knowm type, and is for example formed by a microprocessor 486SL of INTEL Inc.
• the ROM 22, of known type is capable of recording the so-called "firmware" programs, which are developped in the designing stages of the personal computer 10.
• the RAM 23, of known type is capable of recording the programs usually used on the personal computer 10.
• the CMOS RAM 24 of known type, is capable of recording one or more passwords capable of enabling the protection mode according to the present invention
• the SMRAM 25 of known type, is capable of recording the content of the registers which represent the process or the program condition that the personal computer 10 is processing.
• a set of peripheral units 30 of known type is also connected to the CPU 21, comprising a hard disk unit 36, a floppy disk unit 35, a serial port 34, a parallel port 33 and an interface PCMCIA 32.
• the keyboard controller 26 is connected, in a known manner, to the CPU 21 and is capable of being programmed to transmit predefined signals to the CPU 21 in response to the codes received by the keyboard 13.
• SMM System Management Mode
• SMM functionality is caused by a "System Management Interrutp” signal, hereinafter named “SMI” which can be transmitted to a specific pin (PIN) of the CPU 21, in consequence of operation particular conditions or personal computer 10 malfunction, as for example an insufficient power supply.
• SI System Management Interrutp
• the SMM condition is characterized in that the CPU 21, when received the SMI signal, saves in the SMRAM memory 25, the content of the registers which represent the state of the under way process or program and manages the instructions forseen by the personal computer 10 designer for the particular condition happened.
• INDUSTRIAL APPLICABILITY The method operation according to the present invention is the following.
• the keyboard controller 26 interpretes, on the ground of predefined instructions, the codes generated by the stroking as a request to activate the SMM functionality and transmits the SMI signal to the CPU 21.
• the CPU 21 receives the SMI signal, temporarily interrupts the under way operations and carries out the instructions memorized in the ROM 22, that is: it saves in the SMRAM 25 the content of the images present on the display 12 and the necessary data so that the program used at the reception time of the SMI signal can restart after the interrupt; it reads the codes generated by the keyboard stroking on the keyboard controller 26; and sends to the display 12 instructions such as to display a message 14 (Fig. 1) which requires a password stroking for the keyboard 13 protection.
• the password for the keyboard 13 has already been defined, the user must stroke the predefined password for the protection of the same keyboard 13 with the alphanumeric keys 15 (Fig. 2); in case such password has not yet been defined, the user can choose and stroke a new password.
• the CPU 21 restores on the display 12 the images preceding the interrupt caused by the SMI signal, recovering what previously saved by the SMRAM 25, and restarts the processing activity as if no interrupt had taken place.
• the password is kept in memory in the CMOS RAM 24, so that, also if the personal computer 10 is powered off, the password cannot be lost. A possible personal computer 10 power off and power on do not unblock the keyboard 13 use.
• the keyboard 13 unblocking takes place similarly to the blocking.
• the keyboard controller 26 transmits the SMI signal to the CPU 21 that, carried out all the save functions of the context pre-existing in the SMRAM 25, sends a message 14 (Fig. 1) to the display 12 for the stroking of the password.
• the password correct stroking restores the keyboard 13 regular use in addition to the under way processing activity by part of the personal computer 10.
• the keyboard controller 26 transmits the SMI signal to the CPU 21, causing the activation of the SMM functionality and the earring out of the instructions resident in the ROM 22, that, in a manner similar to the one previuosly described, on the ground of the codes read by the CPU 21 on the keyboard controller 26, allows to appear, on the display 12, a password request capable of enabling the display of a further image in order to permit the personal computer 10 configuration.
• the u.ser is able to block or inhibit the access to one or more peripheral units 30 as the hard disk unit 36 (Fig. 2), the floppy disk unit 35, the serial port 34, the parallel port 33 or the interface PCMCIA 32.
• the configuration menu of the personal computer 10 is also provided that the user enables the password use for entering into such menu.
• the password for the protection to configuration menu access of the personal computer 10 is memorized in the CMOS RAM 24 so that it cannot be lost in consequence of the power off of the same.
• the use of the special key 17 in combination with a functional key 16, in order to activate the method according to the present invention is due to a designing choice and not to a really necessity; according to such designing choice the special key 17 has the peculiarity that, if singly stroken, is interpreted by the keyboard controller 26, of neutral type, that is not capable of generating the transmission, in answer to such stroking, any signal to the CPU 21, whereas it is stroked in combination with other keys, is capable of transmitting predefined signals to the CPU 21 on part of the keyboard controller 26.
• the method according to the present invention is applicable, in the case the personal computer 10 is of portable type, also on the rotation of the display 12 from the lowed position on the keyboard 13 to the usual use position.
• the activation of a microswitch is capable of transmitting to the keyboard controller 26 a code equivalent to the stroking of the special key 17 and the functional key 16 associated to it, for example FN+F8, in such a way as to activate the SMM operation very similar to the keyboard blocking and unblocking ones above described.

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• Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Computer Hardware Design (AREA)
• Computer Security & Cryptography (AREA)
• Software Systems (AREA)
• Physics & Mathematics (AREA)
• General Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Input From Keyboards Or The Like (AREA)
• Storage Device Security (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1995
  • 1995-02-21 IT IT95TO000122A patent/IT1279547B1/it active IP Right Grant
• 1996
  • 1996-02-13 WO PCT/IT1996/000027 patent/WO1996026477A1/en not_active Application Discontinuation
  • 1996-02-13 EP EP96902428A patent/EP0811185A1/en not_active Ceased

Non-Patent Citations (1)

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