GB2198567A - Software protection - Google Patents

Abstract

A software protection system incorporates means for inhibiting unauthorised use of the software, comprising a digital magnetic or other recording 15 of the software information, and separate software access-limitation means 16, 18, containing linked information 17 and address indicia 19 which can be sensed by an operator either visually or in a tactile manner, the software including control commands requiring the input of information related to address information generated during operation of at least one software programme, selection of the address information from a set thereof stored on the magnetic recording 15 being effected in a random, pseudo-random or otherwise unpredictable manner and the access limitation means being formed in such a way as to resist duplication by electrostatic photocopying. Alternative forms of the access-limitation means are disclosed (figs. 2-5). <IMAGE>

Description

SOFTWARE PROTECTION The present invention relates in general to software protection, and in particular to a software protection system and an access limitation device for use with software in order to inhibit software copying by unauthorised users.

Considerable effort and expertise is expended in generating software for a computer or a range of computers, and this is reflected in the price charged for an otherwise economically produced magnetic recording containing the software information.

Unfortunately, it is all-too-easy for copies to be made of magnetic discs bearing a recording of expensively produced software, and such copies can be sold cheaply because the copier does not have to amortise the considerable expense in preparing the software in the first place. Such piracy is, unfortunately, inadequately dealt with by the law as it presently stands, and accordingly, ways are sought of making it more difficult to utilise software on a computer unless the software has been genuinely acquired from the original producer.

Prior art attempts to prevent such copying have included varying the sector format of the magnetic disc so that a wide range of discs having different formats are available, the use of donglesw which are devices ancilliary to a computer acting, in the manner of a key, to validate a software user when the software is loaded into a computer and/or when the software is run. A primary disadvantage of the use of dongles is the fact that these are machine-specific whereas it is advantageous if the software can be used on a wide range of different machines. The use of a dongle is also rather expensive from the user's point of view in that an appropriate dongle has to be purchased, not only for a given machine, but also for each software package which may be used on the machine.

The present invention seeks, therefore, to provide means for software protection, by which means unauthorised copying of a software disc can be inhibited if not entirely prevented, at a cost, both from the point of view of the user and the producer which is tolerable within marketing constraints.

According to one aspect of the present invention, therefore, a computer programme protection system includes means identifying a pre-determined coded relationship between demanded and responding values, the software programme incorporating means for issuing and/or displaying a request for a demanded value which can only be determined from external relationship identification means.

In another aspect the present invention provides an accesslimitation device for use with a software recording, comprising means for displaying a plurality of unrelated coded information units on a support which inhibits reproduction thereof, particularly by electrostatic photocopying, and a position-related set of identification indicia enabling the coded information units to be located when called for by the software in use thereof.

In accordance with the present invention, therefore, software may be recorded, as usual, in an appropriate manner, for example on a magnetic disc or other appropriate recording medium, and its above-mentioned external relationship identification means will be associated with each disc. When the software is run it will, at an early stage, issue a request for a coded input from the operator, such coded input being unidentifiable from the request, and only determinable by reference to the external relationship identification means. The software includes a store of the interrelationship between the demand and response values and is therefore able to discriminate between a correct and an incorrect response from the operator when a demand value is displayed. Only if the correct response is keyed in by the operator will the software proceed to the next stage.

By use of such an arrangement it is then unnecessary to incorporate any means in the recording itself which seeks to prevent copying of the recording, such means being difficult to effect and unreliable in the face of continuing attempts to produce recordings. The external relationship identification means will contain the information in a manner which, whilst not making it entirely impossible to reproduce, is such that reproduction is time consuming, expensive and tedious, sufficient to make any attempt at reproducing it unjustified.

Primarily, attempts to reproduce information easily are expected to rely on electrostatic photocopying, and consequently it is envisaged that the information contained on the external relationship identification means will be presented in a way which inhibits reproduction by photocopying. This can be achieved in any one of a number of ways, for example, the external relationship identification means may be formed as a single laminar element bearing printed indicia representing the response information in positions identifiable by address information, perhaps in the form of Cartesian or other coordinates.Photocopying of such information may be inhibited by utilising a background pigment of very similar colour saturation density to that of the information indicia, but of a different chromaticity such as to be readily identifiable to the naked eye, but to produce no detectable boundaries upon photocopying. If colour-sensitive photocopiers are developed which could discriminate between the indicia and the background of such an element other appropriate obscuring means will be necessary. One alternative such obscuring means comprises sealing the laminar element bearing the array of indicia within an envelope having movable windows positionally interlinked such that only one or two sets of indicia can be seen at any one time.This could be achieved, for example, in a rotary embodiment by printing the indicia on a disc held pivotally within an envelope having a window into register with which the indicia can be brought by rotating the disc with respect to the casing. Alternatively, a linear embodiment may be provided by setting out the indicia on a flat rectangular laminar element and providing a cooperating linear or rectangular element slidably fixed to the laminar element and having windows positioned within the body of the element and index marks on the edges enabling the relative positions of the laminar element and the cover to be selected utilising reference index marks constituting the demand value displayed by the computer when running the software, the response values then appearing in the windows.

Other systems for inhibiting photocopying could include placing the indicia within a transparent body shaped such that the indicia cannot be brought sufficiently close to a photocopier bed to produce an image. Embodiments of such an arrangement may include, for example, a triangular prismatic transparent block having the indicia printed on one face, which face is then coated with an opaque material so that the indicia can only be read by viewing through one or both of the other faces of the prism. This idea can be extended to arrangements in which the indicia may be entirely embedded within transparent blocks. Attempts to produce a typewritten copy of the indicia can be frustrated by utilising complex codes of otherwise unrelated groups of alpha-numeric characters. In another embodiment the characters may be embossed onto a substrate or presented in relief so that they are visible to the naked eye, perhaps by reflected light only, but cannot be photocopied. Likewise, indicia may be presented in such a way that they can be identified only in a tactile manner, for example, by positioning the address information in grooves or recesses which can be reached by the fingers, but which cannot easily be seen. If used, a transparent body may include a lens for enlarging the image of the information indicia whereby to make them more readily readable. Such lens may be movable over the surface or may be, for example, in the form of a cylindrical lens which can be observed from any one of a number of difference angles in order to align the eye of the observer with the desired information.

The present invention also comprehends a software system incorporating means for inhibiting unauthorised use of the software, comprising a digital magnetic or other recording of the software information, and a separate software access-limitation device containing linked information and address indicia which can be sensed by an operator (either visually or in a tactile manner), the software including control commands requiring the input of information related to address information generated during operation of at least one software programme, selection of the address information from a set thereof stored in the software being effected in a random, pseudo-random or otherwise unpredictable manner, and the access-limitation device being formed in such a way as to resist duplication, particularly by electrostatic photocopying.

Likewise, the present invention extends to the related inventive concept of an access-limitation device for use in connection with software, comprising a set of data information indicia presented in a random, pseudo-random or otherwise unpredicatable order in a form detectable to a human observer, and in association with address information; the relationship between the address information and the data information being ~stored in a non-detectable way in recorded software, which includes instructions whereby to provide a request for data input by indicating the address thereof during operation of the programme.

Address and/or information indicia may also be formed in a way which is normally invisible, being rendered visible by operator action, for example illumination with ultra violet light, application of an electric field or current, or the like. Thus, in a more sophisticated embodiment, the laminar element containing the information indicia may be a large-scale array of liquid crystal display elements which can be caused to produce a display upon depression of appropriate keys of a keyboard which may be a compact, alpha-numeric keyboard or an extended linear array of keys, for example, along one or two edges of the laminar element.

Various embodiments of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic perspective view of a computer and a software protection system formed in accordance with the principles of the present invention; Figure 2 is a perspective view of a magnetic disc and a casing therefore incorporating an access-limitation device of the invention; Figure 3 is a perspective view of a further access-limitation device formed as an embodiment of the invention; Figure 4 is a schematic perspective view of a further access-limitation device formed as another embodiment of the invention; and Figure 5 is a schematic perspective view illustrating a further embodiment of the invention.

Referring now to Figure 1 there is shown a computer generally indicated 11 having a display screen 12 and, in this embodiment, two apertures 13, 14 for receiving magnetic discs, one of which would normally be used for loading a programmet and the other of which could be used for a work disc containing user data.

The software is recorded on a magnetic disc 15 which, when not in use, is stored in a casing or cover 16 which has, formed integrally therewith, at least one flap 17. On the outside cover of the casing 16 and on the flap 17 are printed a plurality of complex information indicia, as groups of alpha-numeric characters in a random or rather, apparently random form set out in rows and columns which can be accessed by address information in the form of starts or arrows printed along two adjacent edges, for example along the left hand or the bottom edge of the flap 17 (or, indeed, along both). An overlay sheet 18 having a plurality of apertures 19 can be positioned over the flap 17 and casing 16.It would of course be possible to form an alternative embodiment in which the overlay sheet is part of the casing and the flap 17 replaced by a sheet or plurality of sheets in a book or booklet (which can be put in the case). The software recorded on the disc 15 contains a table of the information indicia in the form of passwords. This table is in the "object code", so it cannot be understood simply by listing the programme on the screen or printing it out. When the software is used the programme generates at random (or apparently at random, this being related, for example, to the time between switching on and first key depression or the times between selected key depressions in operating the computer, for example the first three key depressions).The screen 12 then displays an indication of the address information to which the overlay sheet should be moved by reference to index marks thereon, and then asks for input of information visible in one or more of the apertures 19. The operator must then respond by identifying the group of alphanumeric characters visible in the apertures 19 represented by the numbers displayed on the screen, and by keying in this code. The programme compares the code keyed in by the operator with that which it identifies on its own internal table and if these two coincide the programme continues. If they do not coincide an error code is generated giving the operator a second chance, in order to avoid keying errors when entering the code, and if the desired coincidence is still not detected the user is returned to the operating system via a suitable message.

Attempts to copy the data on the casing 16 and flap 17 are made difficult by the nature of the materials used for these and for printing thereon. For example, dark maroon or brown paper printed with blue ink, whilst producing visible discrimination to the naked eye, is effectively invisible to a photocopier. Thus reproduction of the programme security information, whilst not being entirely impossible in that it could be achieved by laboriously reading and transcribing the data by hand or on a typewriter is nevertheless so difficult as to constitute an effective deterrent to piracy.

Very often software consists of only one programme. In some cases, however, software comprises several programmes which can be run independently and rather than setting up the same security system for each programme in the software, it is possible to provide a "preliminary" programme which must be run through before any of the other programmes are used. This preliminary programme then leaves a special user validation code in a suitable place where it can be read by the other programmes making up the software package. If the machine has a "memory disc" (for example the "M:Drive on the Amstrad PCW) a suitable place for such a code would be a file in the memory drive. This is particularly appropriate because the validation code will automatically be erased when the machine is switched off, and can be erased by the software package upon returning to the operating system, thus making it very difficult for a user to identify its location and form. In an alternative embodiment the user validation code can be stored on a floppy disc, which may either be the programme disc or the user's work disc; although in this case it will be necessary to conceal this code and/or to erase it when a situation arises such that a new validation check is required. ' In a situation where there are several programmes the user validation code may be present as a variable having a transferable value upon changing programmes (where most variables would automatically revert to zero).

In operating the software, then, the other programmes in the set include a routine to check whether the user validation code has been correctly entered. Two alternative systems may be utilised at this point. Either the subsequent programmes may include a routine requesting the "preliminary" programme to be run, or they may assume that the user has been denied access to the first programme and is therefore not a valid user. In this latter case the programme would return the user to the operating system via a suitable message. The form of the validation code may be different from time to time so that it cannot be located, recorded, and reused at a later date. A simple technique, for example based on the date or the number of times the programme has been run may be employed.

Referring now to Figure 2, an alternative embodiment is illustrated, in which a casing 20 for a magnetic floppy disc is formed with a pocket 22 for receiving the disc and a twin-layer cover forming a further pocket (not visible in the drawing) for receiving a printed disc 23 bearing indicia which are visible through openings 24, 25 in the casing 20. The openings 24, 25 are located at different radial positions from a centre 26. The indicia visible through the two apertures 24, 25 are marked on the disc 23 in two separate rings, the ring of indicia visible through the aperture 24 being sequential address information and the indicia marked in the ring visible through the aperture 25 being random alpha-numeric characters constituting the response code.

When the programme on the disc 21 is run, it produces an address code which is dependent, as indicated above, on various unrelated factors so that it is unpredictable from time to time, and by turning the wheel 23 the user can then cause the address displayed on the computer screen to be brought into register with the aperture 24 whereupon the corresponding indicia visible through the aperture 25 can be entered through the keyboard. As in the embodiment of Figure 1, the primary function of the case 20 and wheel 23 is to conceal the relationship between the address information and the indicia constituting the response information.

Again, therefore, appropriate anti-photocopying measures may be taken, such as appropriately coloured pigments for the printing, or the indicia may be marked by embossing on a plain opaque or transparent substrate. Embossed marks can be read relatively easily by an observer capable of positioning the substrate at an appropriate angle to receive reflected light, but would not produce an adequately dense image for photocopying since the illumination of a photocopier bed is substantially normal to the plane of the substrate. Thus, even if the casing 20 were torn apart to expose the whole of the information in the rings on the disc 23, reproduction would be difficult except by producing a typed copy, and by making the casing 20 of tough plastics material, perhaps riveted through the centre spindle 26, attempts at destructive interference can be seriously inhibited.

Referring now to Figure 3 an alternative carrier for the coded information is illustrated. In this embodiment a substrate 31 bearing the information indicia in rows and columns identifiable by appropriate letters and numbers is secured to one face of a triangular transparent prism 32 and overlain with an opaque coating 33. The prism 32 holds the visible face of the substrate 31 in such a way that it cannot be positioned for photocopying, whilst the number and complexity of entries on the substrate 31 inhibits direct reproduction by reading off and typing. It is envisaged that such an element could be, for example, 12 to 18 inches (30-45 cm) in length and, say, 2 inches (5 cm) in height.

Figure 4 illustrates a further variant of this concept in which a substrate 41 is attached to one face of a triangular transparent prism 42 having two semi-cylindrical axially extending beads 43, 44 on two opposite faces. Again, an opaque layer 45 is secured over the substrate 41 to prevent its removal from the prism 42. In this embodiment the indicia printed on the substrate 41 can be collapsed, at least in the "vertical" sense (that is transversely of the length of the prism) and only selected rows of indicia can be observed at any one time by appropriately positioning the eye of the observer. The indicia can be marked in two opposite orientations so that they must be observed through the cylindrical lenses 43, 44 as appropriate, and by printing alternate rows in opposite orientation this can further inhibit any attempt to make a copy of the information.

Finally, Figure 5 illustrates another embodiment in which the carrier for the coded information is formed as a corrugated laminar substrate, for example made from a flat sheet of plastics material printed in such a way that the surface is smooth, or substantially smooth so as to prevent copying, for example by a technique similar to that of brass rubbing. The substrate, which is indicated with the reference numeral 51 in Figure 5, is corrugated with a plurality of sharp ridges 52 and troughs 53 separated by substantially planar strips bearing the coded information.The corrugations defined by the ridges 52 and troughs 53 give the material a substantially saw-tooth cross-section and the material from which the substrate 51 is formed is one which, after the corrugations have been introduced (which may be before or after printing with the coded data 54) it cannot be flattened out such as to permit photocopying without fracturing along the lines defined by the crests and troughs 52, 53 respectively and, further, loss of at least some of the data by crazing or obscuring in the region of the stress lines applied by the attempt to flatten the material.

As shown in Figure 5 this embodiment incorporates a plurality of substrates 51, three of which are illustrated in the drawing and identified with the reference numerals 51a, 51b and 51c. These are linked together by a loop 55 passing through a hole 56 in one corner of the substrate. A greater or smaller number of substrates may, of course, be provided and these may be held together in a book or otherwise.

Identification of the information required by a computer programme is achieved using a template 57 which is formed with a corrugated shape matching that of the substrate 51, namely having elongate rectilinear crests and troughs SS, 59 respectively matching the crests and troughs 52, 53 of the substrate 51. As shown in Figure 5 the substrate 51 and template 57 have five crests 52, 58 respectively and four troughs 53, 59 respectively. There may, however, be a different number from this (either larger or smaller) according to requirements. The crests 58 and troughs 59 of the template 57 are separated by respective flat faces 60, 61 the latter of which are provided with markings representing "windows" 62 each identified with an associated reference numeral or letter.

The template 57 may be transparent, in which case the "windows" 62 are represented by opaque marks on the faces 61, or alternatively the template 57 may be opaque with the windows 62 formed as transparent elements or openings in the faces 61. In the embodiment illustrated no windows are formed in the faces 60 and likewise no data is marked on the reverse faces of the corrugations from those bearing the data 54. Again, in other embodiments, both flat faces of each corrugation of the substrate 51 may be provided with data and likewise, both flat faces of the corrugations of the template 57 may be provided with windows to increase the useful working area thereof.

As with the other embodiments, when the computer programme is being run, (for example to load it into RAM from a disc drive) a screen prompt is generated to request the operator to enter the data appearing at a combination of windows. Additional complexity can be introduced by means of a further row of indicia 63 on the substrate 51 and a master window or reference point 64 on the template 57. The row 63 extends parallel to the corrugations defined by the crests and troughs 52, 53 so that the windows 62 can effectively display different data items 54 when the template 57 is moved so that the reference point 64 is in register with different indicia 63. Again, the screen prompt can identify the relevant index at which the reference point 64 is to be positioned prior to reading the data exposed through the window 62 in that position.

As with the previous embodiments, any attempt to reproduce the data substrate 51 and/or the template 57, are frustrated by the corrugations holding the data and index windows away from a photocopier surface and the rigidity or fragility of the material frot-which these components are made prevents them from being flattened out in order to make copying possible.

Claims (15)

1. An access-limitation device for use with a software recording, comprising a plurality of unrelated coded information units formed or carried on a support the nature of which inhibits reproduction thereof, at least by electrostatic photocopying, and a position-related set of identification indicia enabling the coded information units to be located when called up by the software in use thereof.

2. A computer programme protection system, including an access-limitation device as claimed in Claim 1, for identifying a predetermined coded relationship between demand and response values, the programme incorporating means for issuing and/or displaying a demand value constituting a request for a response value which can only be determined from the said external relationship identification means.

3. A software system incorporating means for inhibiting unauthorised use of the software, comprising a digital magnetic or other recording of the software information, and a separate software access limitation device containing linked information and address indicia which can be sensed by an operator (either visually or in a tactile manner), the software including control commands requiring the input of information related to address information generated during operation of at least one software programme, selection of the address information from a set thereof stored in the software being effected in a random, pseudo-random, or other unpredictable manner and the access-limitation device being formed in such a way as to resist duplication, particularly by electrostatic photocopying.

4. A system as claimed in Claim 3, in which the access limitation device comprises at least one laminar element having visible indicia marked thereon and a background of a form or colour to which electrostatic photocopiers are strongly sensitive whilst the indicia are marked in a form or colour to which an electrostatic photocopier is less strongly sensitive.

5. A system as claimed in Claim 3 or Claim 4, in which the software access-limitation device has a background which includes irrelevant indicia marked in a distinguishing colour of comparable colour density to that of the marked indicia.

6. A system as claimed in any of Claims 3 to 5, in which the software access-limitation device includes information indicia printed on a substrate having a similar colour saturation density to that of the information indicia but a different chromacity, such that the boundaries of the indicia are substantially undetectable upon photocopying.

7. A system as claimed in any of Claims 3 to 6, in which the access-limitation device includes two parts, one of which is adapted or arranged to overlie the other and is provided with apertures through which information indicia on the said other can be made visible to an observer in dependence on the relative position and/or orientation of the said two parts.

8. A system as claimed in Claim 7, in which the said two parts of the access-limitation device are provided with indicia for determining selected relative positions and/or orientations thereof by positioning selected said indicia in coincidence with one another.

9. An access-limitation device for use in connection with software, comprising a set of data information indicia presented in a random, pseudo-random or otherwise unpredictable order in a form detectable to a human observer and in association with address information; the relationship between the address information and the data information being stored in a non-detectable way in recorded software, which includes instructions whereby to provide a request for data input by indicating the address thereof in a random, pseudo-random or otherwise unpredictable manner.

10. An access-limitation device as claimed in Claim 9, which device includes means for making the data information indicia observable, such as by illuminating with ultra violet light.

11. An access-limitation device as claimed in Claim 9 or Claim 10, in which the data indicia are formed within or on one face of a transparent body shaped such that the indicia cannot be brought sufficiently close to a photocopier bed to permit reproduction thereof.

12. An access-limitation device as claimed in any of Claims 9 to 11, in which the said substrate or body is shaped with a plurality of corrugations in the form of substantially flat faces between parallel rectilinear crests and troughs.

13. An access-limitation device as claimed in Claim 11 or Claim 12, in which the surface of the said transparent body is formed with a convex portion acting as a lens to magnify the image of information indicia present within the body or on a face thereof.

14. An access-limitation device substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

15. A software protection system substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.