EP0811185A1

EP0811185A1 - Method for protecting an electronic computer

Info

Publication number: EP0811185A1
Application number: EP96902428A
Authority: EP
Inventors: Vincenzo Ianieri; Gian Luigi Cargnino
Original assignee: Olivetti SpA; Ing C Olivetti and C SpA
Current assignee: Telecom Italia SpA; Olivetti SpA
Priority date: 1995-02-21
Filing date: 1996-02-13
Publication date: 1997-12-10
Also published as: ITTO950122A1; WO1996026477A1; ITTO950122A0; IT1279547B1

Abstract

A method for protecting the use of a computer (10) against a non-authorized user, by way of the stroking of the combination of one or more keys of a keyboard (13). The method allows to interrupt temporarily the computing activities of the computer (10) to display on the display (12) the request of a password (14), that, if correctly stroked, is capable of selectively activating as well the blocking and the unblocking of the keyboard (13). Moreover such method allows the access to the configuration menu of the computer (10), and the selection of the peripheral units to be locked or enabled to the use. By way of such method the user has the whole control of the operations concerning the protection of the computer (10), as the access to the functionalities, as well as the keyboard (13) blocking/unblocking as well as of configuration, is always supported by messages (14) displayed on the display (12).

Description

"METHOD FOR PROTECTING AN ELECTRONIC COMPUTER" TECHNICAL FIELD

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. In particular 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. DISCLOSURE OF THE INVENTION

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.

All that is obtained by way of the method for protecting an electronic computer according to the present invention, which is characterized in that 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.

According to a further feature of the present invention also the access of the user to the computer configuration can be protected by way of a password which can be defined by the same user and without modifying the usual computer activity flux. According to another feature of the present invention, the innovatory method allows, in any moment and independently from the computer, to enter into the computer configuration menu and to protect or inhibit the use of one or more peripheral units, as the hard disk or the floppy disk units, the serial or parallel ports and the interfaces PCMCIA, connected to the computing unit of the same computer. BRIEF DESCRIPTION OF DRAWINGS These and other features of the present invention will be clear by the following disclosure of a preferred embodiment, given by way of non-limiting and not restrictive example, with reference to the accompanying drawings, in which: Fig. 1 is a perspective and schematic view of a portable personal computer which uses the method according to the present invention; and

Fig. 2 is a logic operation diagram of the personal computer of Fig. 1

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to Fig. 1, the protecting method according to the present invention, also if applicable to any computer, 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.

Referring to Fig. 2 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 13, that, in addition to the usual alphanumeric keys 15 and functional keys 16 comprises also a special key (FN) 17, is connected, in a known manner, to a keyboard controller unit 26, preferably of the type 80C51SL of INTEL Inc.; the keys of said keyboard 13, if stroked, are capable of transmitting predefined codes to the keyboard controller 26.

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.

Before disclosing the protecting method, according to the present invention, it is useful to give some information about the operation features of the microprocessors type SL, normally in use on personal computers, and therefore about of CPU 21.

As it is known, such microprocessors support a system management functionality of protected type called "Protected and System Management Mode", hereinafter named SMM. 5

The 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.

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.

As a user strokes a keys combination comprising the special key 17 and a predefined functional key 16, for example FN+F8, 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.

As 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. In case 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.

As the user has stroken the 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.

But from now onwards the keyboard 13 is unusable and prohibits use on the part of a user who is not familiar with the password; the duration of such situation is shown by the flashing of two light-emitter diodes opposite the keyboard 13, not shown in the drawings.

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. After a user strokes the special key 17 and a predefined functional key 16, for example FN+F8, 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.

According to a further use of the method according to the present invention, it is possible for a user, as it will be clear by the following disclosure, to reconfigurate the personal computer 10 and to define the peripheral units 30 which access must be protected. In any moment of the personal computer 10 use, the stroking of the combination of the special key 17 with a predefined functional key 16, for example FN+F4, once again is interpreted by the keyboard controller 26 as a request of the SMM functionality activation.

Also in this case 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.

By the way of such further image or configuration menu 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. In the configuration menu of the personal computer 10 is also provided that the user enables the password use for entering into such menu. Also 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 use of one or more alphanumeric keys 15 in combination, when possible and easily actuable, could have the disadvantage to limit the use of any applicative program which would use just that key or that keys combination in order to execute control functions of the same program. The solution adopted to use in combination a special key 17 with functional keys 16 grants the possibility of not interfering with any applicative program.

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.

In such case the activation of a microswitch, not shown in the drawings, 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.

Obviously changes may be made or parts may be added to the method and to the computer above disclosed, without departing from the invention sphere.

Claims

1. Method for protecting an electronic computer having a keyboard and a display unit, comprising the steps of stroking at least one predetermined key of said keyboard to activate the locking of said keyboard; and stroking a determined password on said keyboard to unlock said keyboard and restore its use, characterised in that said stroking of at least one key causes said display unit to display a message indicative of the requiring the stroking of said determined password either for locking said keyboard or for unlocking said keyboard in the event this latter is in a locking condition.

2. Method for protecting an electronic computer having a processor unit, a keyboard and a display unit, comprising the steps of stroking at least one predetermined key of said keyboard and displaying a configuration menu on said display unit in answer to said stroking, characterised in that said stroking causes said processor unit to display on said display unit a message requiring the stroking of a determined password on said keyboard, the stroking of said determined password causing said processor unit to display on said display unit said configuration menu.

3. Method for protecting an electronic computer having a processor unit, a keyboard, a display unit and at least one peripheral unit comprising the steps of stroking at least one predetermined key of said keyboard, displaying a configuration menu on said display unit in answer to said stroking and configuring said at least one peripheral unit through the modification of said configuration menu, characterised in that the step of configuring said at least one peripheral unit further comprises the step of selectively locking/unlocking said at least one peripheral unit.

4. Electronic computer comprising: - a keyboard for inputting data; a processor unit connected to said keyboard for processing said data;

- a display unit connected to said processor unit for displaying predetermined messages associated to commands coming from said processor unit; and

- memory means connected to said processor unit for storing computing data, characterised by interrupt means, connected to said processor unit, and actable by a predetermined key of said keyboard, for temporarily interrupting the processing of said data; displaying a message on said display unit requiring the stroking of a determined password; and storing on said memory means the computing data which are elaborating at the temporarily interruption moment.

5. Electronic computer according to claim 4, characterised in that said electronic computer further comprises recognition means connected to said processor unit for recognising the correct stroking of said determined password; and activating the locking of said keyboard or the unlocking of said keyboard in the event this latter is in a locking condition.

6. Electronic computer according to claim 4, further comprising at least one peripheral unit connected to said processor unit for exchanging data with said processor unit and configuration means connected to said processor unit for configuring said electronic computer, characterised in that said electronic computer further comprises recognition means connected to said processor unit for recognising the correct stroking of said determined password and displaying a configuration menu indicative of the configuration of said electronic computer on said display unit.

7. Electronic computer according to claim 5 or 6, characterised in that said electronic computer further comprises restarting means connected to said processor unit for recovering from said memory means said computing data; and restarting said processing of said data, independently from the correct stroking of said password.

8. Electronic computer according to claim 4, characterised by non volatile and re-writable memory means connected to said processor unit, for storing said determined password.

9. Electronic computer comprising:

- a keyboard for inputting data; - a processor unit connected to said keyboard for processing said data;

- a display unit connected to said processor unit for displaying predetermined messages associated to commands coming from said processor unit; - first memory means connected to said processor unit for storing computing data; and configuration means connected to said processor unit for configuring said electronic computer, characterised in that said electronic computer further comprises: second memory means non volatile and re-writable connected to said processor unit for storing at least one password; and

- interrupting means connected to said processor unit, and actable by a predetermined key of said keyboard for temporarily interrupting the processing of said data; displaying on said display unit a message requiring the stroke of said at least one password; and storing on said first memory means the computing data which are elaborating at the temporarily interruption moment, the correct stroking of said at least one password selectively activating or the locking/unlocking of said keyboard; or the displaying a configuration menu on said display unit.

10. Electronic computer according to claim 9, further comprising at least one peripheral unit connected to said processor unit for exchanging data with said processor unit, characterised in that said electronic computer further comprises reconfiguration means connected to said processor unit for selectively locking/unlocking said at least one peripheral unit.