COMPUTER SYSTEM

Abstract: A computer system (10) comprises a computer (13) associated with a disc reader (12) for loading a program recorded on magnetic disc (11) into the computer (13). A pre-programmed security card (16) is loaded into a card reader (15) which is coupled to the computer (13) and the program encoded on disc (11) is formed by program data for operating the computer (13) and security data for inhibiting unauthorised use of the computer program in the computer (13). The security data is formed by interrogation data arranged to interrogate the card reader (15) via the computer (13), identification data for effecting a comparison with the pre-programmed security card data and disablement data for inhibiting further operation of the computer program in the computer (13) in the absence of concurrence in the comparison.

Description: COMPUTER SYSTEM This invention relates to computer systems. At the present time it is very easy to copy computer programs without authority and to use the unauthorised copy in a computer. This is undesirable and it is therefore an object of the present invention to obviate or mitigate this disadvantage. According to the present invention there is provided a computer system characterised by the combination of a computer program recorded on a machine-readable medium, a computer, means for loading said program into said computer, a card reader coupled to said computer, and a pre-programmed security card capable of being loaded into said card reader, wherein said computer program comprises program data for operating said computer and security data for inhibiting unauthorised use of the computer program in said computer, said security data being formed by interrogation data for interrogating the card reader via -the computer, identification data for effecting a comparison with the pre-programmed security card data, and disablement data for inhibiting further operation of the computer program in the computer in the absence of concurrence in said comparison. It will be understood that in accordance with the present invention each program may be recorded on magnetic tape or disc and the program distributor issues with each program an appropriate security card so that when the program is in use in a computer the computer will only run in the presence of the .security card which is correct for the particular program. The security card may conveniently be in the form of a plastic carrier with read-only pre-programmed magnetic strips, generally similar to cards conventionally used nowadays for banking and cheque encashment purposes, or alternatively may take the form of a plastic carrier incorporating a signal processing chip with pre-programmed memory. When the computer is operating in accordance with the program data of the computer program, and at intervals while the software is running, the security data interrupt the program data to interrogate the security card and compare some or all of the pre-programmed data therein with the identification data within the program. If the returned data message does not agree with that of the identification data the disablement data inhibits further operation of the computer so that the computer program does not run any further and effectively is worthless to the user. If the returned data message does agree with the identification data the disablement data is inhibited from operating and the computer program continues to run. With the system of the present invention as many copies of the computer program may be made as the user desires but because only one security card exists (being associated with the originally distributed program) only one of the copies can be used at a time. If multiple machine operation is required multiple security cards are required and can be purchased from the program distributor In this connection it will be appreciated that unauthorise copying of the security card whilst not entirely impossibl is very substantially more complicated than unauthorised copying of a program recorded on magnetic tape or disc and is well beyond the abilities of the average program user. It will be understood that the reader for the security card may be used to read more than one security card at any one time where more than one program is used concurrently in the computer (e.g. operating systems software, application software, compiler software, interpreter software) . The reader may be of the type which reads a security card statically, or dynamically during insertion of the security card, and conveniently is attached to the serial printer or TTY port of the computer. It will also be understood that the identification data, and preferably the entire security data, is encrypted in such a way as to make it difficult to decode. Preferably also the security data is in the form of disguised calls to a program data routine. An embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 illustrates the computer system in block format; Fig. 2 illustrates a detail of the Fig. 1 system; and Fig. 3 illustrates the organisation of the software used in the Fig. 1 system. As is shown in Fig. 1 a computer system 10 comprises a magnetic disc 11 on which is recorded a computer program, the disc 11 being removably mounted in a disc-reading device 12 coupled to a computer 13 by way of a data trans- mission path 14. Connected to computer 13 by way of its serial printer port is a card reader 15 releasably containing a security card 16 having pre-recorded or "BUREAU OMPI WIPO *J programmed data thereon. Fig. 2 illustrates card reader 15 in greater detail in order to illustrate its preferred ability to house concurrently several cards 16 respectively associated with several programs which may operate concurrently within computer 13 having been sequentially loaded therein from a pertaining disc 11 by way of the device 12. Fig. 3 schematically illustrates the organisation of the security data software provided by a single program on a disc 11. Thus, when the computer 13 is in its RUN mode whereby the program of disc 11 is rendered operational (or at least quasi-operational by virtue of the present invention) there intermittently occurs during the program data the security data which initiates, via computer 13, the sequence of events denoted by blocks 20 to 30. Accordingly block 20 arranges interrogation of card reader 15 to determine the presence or absence of a specifically identified card 16 as indicated by blocks 21, 22. In the event of the required card 16 being present a password identified in block 20 is applied to the card 16 to determine whether or not that password is meaningful as indicated by block 23. In the event that the password is meaningful a card response, indicated by block 24 is established which is checked comparatively by computer 13 with the identification data of the program as denoted by block 25. In the event of concurrence in the comparison as denoted by block 26 the computer 13 is signalled to permit the program to continue running, as indicated by block 27. In any case where a negative response is achieved a 'NO* signal is returned to the computer 13 as indicated by block 28 which results in the computer 13 displaying a standard shut-down message on its VDU as denoted by block 29 the program is rejected, that is inhibited from further operation within the computer "13 as indicated by block 30.

Claims: CLAIMS 1. A computer system characterised by the combination of a computer program recorded on a machine-readable medium (11) , a computer (13) , means (12) for loading said program into said computer (13), a card reader (15) coupled to said computer (13) , and a pre-programmed security card (16) capable of being loaded into said card reader (15) , wherein said computer program comprises program data for operating said computer (13) and security data for inhibitin unauthorised use of the computer program in said computer (13), said security data being formed by interrogation data for interrogating the card reader (15) via the computer (13) , identification data for effecting a comparison with the pre-programmed security card data, and disablement data for inhibiting further operation of the computer program in the computer (13) in the absence of concurrence in said σomparison. 2. A computer system as claimed in claim 1, characterised in that the security card (16) is in the form of a plastic carrier with read-only pre-programmed magnetic strips. 3. A computer system as claimed in claim 1, characterised in that the security card (16) is in the form of a plastic carrier incorporating a single processing chip with pre¬ programmed memory. 4. A computer system as claimed in claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.

Inventors: GARDINER ALEXANDER BATTISON, GARDINER, ALEXANDER, BATTISON
Applicants: GARDINER ALEXANDER BATTISON, GARDINER, ALEXANDER, BATTISON
Application year: 1984
Main classification: G06F1
IPC codes: G06F1, G06F21