GB2144247A - Security against copying recorded media - Google Patents

Abstract

A machine readable program carrier has main and further program material. The latter is used to provide an operator with a first parameter. The operator has a separate record correlating each first parameter with a second parameter and the operator must enter the correct second parameter in order to use the main program material. The separate record may be a grid arrangement of multi-colour codings identifiable by row-and-column and preventing monochrome copying. <IMAGE>

Description

SPECIFICATION Security against copying recorded media The invention relates to methods and means for affording security against copying, particularly, but not necessarily exclusively, of computer program material recorded on machine-readable media such as magnetic tapes or discs, even in chip form as ROMS or EPROMS.

The practice of unauthorised copying of computer program material, whether for the well-known computer games or for other software systems and facilities, is widespread, illegal and very much to the detriment of the industry in terms of viability and growth of firms developing and selling software, and consequently, ultimately, the customer as to prices and availability of products.

It is conservatively estimated in the computer games trade that, on average, each genuine cassette game sold gives rise to five or more unauthorised copies.

This situation has led to many programs available on cassettes being "defended" against copying by building in various program tricks so that they cannot be re-recorded via computers to another tape. That is often effective also to prevent transfer to another medium, for example discs, which is exceptionally irritating to the bona fide user. Hov-./ev- er, it does nothing to stop recording one tape onto another using two cassette tape machines or a machine of the type (becoming suspiciously commonplace) having two built-in cassette decks.

Accordingly, there is a great need for an improved security system, particularly one that leads away from obstructing transfers from tapes to discs, and generally reduces the tendency to introduce spurious traps into program material.

To that end, this invention proposes that a carrier for main program material is further associated with data representing a plurality of information items and with subsidiary program material that results in identifying, preferably unpredictably, one such information item by one parameter, say a label or pointer, different from another parameter, say actual content, of that information item, and a separate record of all of said information items each identifiable by the first parameter and disclosing the second parameter, said subsidiary program material being responsive to user entry of the right said second parameter to enable operation of main program material.

The second parameter or, for convenience, actual content of the information items is preferably something that is at least difficult to copy when embodied on the separate record, which is usually a visual record, say as a sticker on the cassette or its case or incorporated in the usual cassette card or separate therefrom. Whilst it is accepted that any such material is readily copied in back-and-white on widely available copiers, copying of colours is much less readily available and it is thus proposed that the information item contents be areas of colour, preferably several different such sub-areas for each item.

Even a choice of three colours in two sub-areas gives nine possible combinations and four colours on four sub-areas gives 256 possible combinations. Naturally, shades of colours with similar tonal values that do not easily permit of distinction by black-and-white reproduction are preferred, say the three primary colours plus yrey/black.

Virtually all computer systems in use for packaged commercial software have a visual display unit and a keyboard input. Accordingly, preferred embodiments of this invention can be conveniently implemented by the subsidiary program material causing display of a label or pointer (first parameter) and requiring actual content (second parameter) of the corresponding information item to be entered via the keyboard before enabling operation of the main program material. The label or pointer may be a grid reference to a matrix of information items on the separate record.

It is recognised that the apparatus to which this invention applies is a computer system and that such could readily be programmed to cycle through all possible information contents of the format just suggested. Accordingly, it is particularly preferred herein that the subsidiary program material be operative only after a loading-to-computer operation for the main program material and that the latter be wiped from the computer store if incorrect information content is entered by the user. That would then require multiple loading operations, and time, in order to investigate different possible information contents, even if at least one operator error is allowed, but not, of course, too many, before wiping the store.

A particularly advantageous security feature arises from the subsidiary program material being unpredictable as to choice of lable/pointer, say operating according to contents of particular stages of a counter, clock or timer register or a random generator facility of the computer whether present as hardware or permanently resident in operating system software (usually called firmware).

Then, even with the same program carrier, the enabling information item can be any one of the plurality allowed for on the separate record, and without fore-knowledge of which one will be concerned at each loading operation. Accordingly, only a user with both of the carrier, or a copy thereof, and the separate record can load and run the main program material.

Specific implementation of the embodiments of this invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows diagrammatically tape contents; Figure 2 shows diagrammatically a separate record; Figure 3 shows diagrammatically and to an enlarged scale a portion of the record of Figure 2; and Figure 4 shows a flow chart for subsidiary program material.

In Figure 1, cassette tape is indicated (unreeled) as carrying main program material recorded in block A, data for information items in block B, and subsidiary program material recorded in block C. It will be appreciated that the order in which those blocks A, B, C appear, even whether one is within or partly within another or others, is a matter of choice and corresponding programming.

In Figure 2, a separate record is shown as a sheet or a portion of a sheet bearing a 16 x 16 matrix of areas each constituting a different information item identifiable by a label or pointer constituted by a row/column type grid reference A-P, 1-16. It will be appreciated that a suitable lay-out could be other than a square matrix form, say a lesser number of rows and a greater number of columns or vice versa in a generally rectangular array, or some other geometric layout, and could be of a total number of items less or greater than 256.

From Figure 3 will be apparent that each information item, say as an area of the matrix of Figure 2, can comprise four bands of colours, say selected from red(R), blue (Be), greeen (G) and black (Bk), the latter, in practice normally being a grey tone matching tonal values of shades of the other colours used.

It will be appreciated that bands read from left to right are particularly easily and naturally read, though the opposite is feasible, as are arrangements of quadrants, dots, rings, sectors of a circle, or whatever is desired. Moreover, one of the sub-areas may always be distinguishable from the others, say as to width, incorporation of a dot of another colour etc. as the start for order of identification.

No security system is unbeatable, but the potential for resisting all but good colour reproduction is very high in the present proposals. A relatively small size of information item area, itself subdivided, offers good security even then, say against all but expensive photographic equipment beyond the likelihood of the relatively casual piracy of a group of fairly impecunious friends or acquaintences.

Typical subsidiary software relative to Figure 2 is shown in Figure 4 where the first step is unpredictably to produce a grid reference, say by looking at four specified stages of a register'counter/timer of the host computer, converting same to alphabetical/ decimal, displaying the results, then waiting for data entry.

At anytime between generation and data entry the subsidiary program material will look up the contents of the identified item in the data block B, probably using an hexadecimal block/byte identifier as no more than two bits are required to identify which of four colours is present in each band or other subarea.

At data entry, the subsidiary program material compares input data (looked up on the separate record and keyed in by the user) with data looked up from block B and enables the main program if they correspond.

Traversal of the comparison stage twice is shown to be permitted after which the subsidiary software wipes the computer store, thereby requiring complete reloading in order to try again.

It will, of course, be appreciated that the first box in Figure 4 could be replaced by a "Get Random Number 0-255" if the host computer can comply.

It will be appreciated that for a preferred system hereof that has n unpredictably selectable different information items, the chances of successfully guessing the second parameter (specifically actual content) of a selected item at any attempt is 1-in-n, and even allowance for one erroneous entry on each loading means that only a 2-in-n chance of guessing right arises for each loading of program material.

Moreover, the actual pattern or organisation of the information items for any one particular set layout, i.e. organisation of first-parameters (specifically grid reference) can be subject to n! variations of relation- ships between those first and second parameters, and there is a very large number of possible variations of layout even for a basic grid or matrix structure that, of course, need not be full rectangular, let alone square, and could be triangular, even use some other coordinate system such as polar, perhaps successively outward "rings" thereof doubling the number of items on the separate record.

An advantage is that even within any particular layout, different organisations of information items can be applied, whether for different main program carriers or to convenient production runs of main program carriers or a combination of both.

Though clearly not limited to such in principle, it is envisaged that embodiments of the invention will find particularly advantageous application to cassettes or copiers of program material because those do tend to have a longer loading time.

Aspects of embodiments hereof include: (a) the carrier with data recorded matching a particular separate record and program material to require successful matching to enable running main program material.

(b) method of installing data and related program material on a machine-readable carrier and associating same with a corresponding separate record in a carrier package with security features.

(c) variation of stored data and corresponding separate record from batch to batch or from type or type of program carrier.

(d) unpredictability of selection of information item and thus requirement for looking up from a separate record.

(e) use of information items that include material resistant at least to monochrome copying.

Alternatives to the colour coded separate record are feasible, though much more costly, for example providing a device, perhaps resembling a pen, for reading magnetic or other coding. However, heat sensitive paper also affords possibilites for local requirements in terms of reading particular information items. Moreover, any record hereof could be placed on a 3-dimensional article so as to increase difficulty of any photographic copying, whether on a cube or sphere, or even on sides of the cassette case.

The system and method hereof is, of course, readily extended to whatever size and specific format is found to be adequate to deter laborious transcription of colour-codings or equivalent into key identifiers or the like. Thus latest versions hereof run to an array of four-colour areas having 70 columns and 26 rows (A-Z). Moreover, in order to combat colour-blindness, even if only partial but relative to two or more used colours, actual key identifications may be imprinted, say as different shades of a colour not much, if any, subject to colour-blindness (e.g. yellow), and preferably further in hologram form the better to still inhibit normal copying.

In the appended claims, the term machinereadable has its normal meaning compatible with automatic entry into a computer from a tape, disc or whatever.

Claims (7)

1. In combination, a machine-readable carrier for program material bearing main program material and further or incorporated program and data material, and a separate record of that data material from which an operator can correlate first and second parameters of each of information items of said data material, said further or incorporated program material serving to cause identification of a said information item by its said first parameter and being responsive to operator-entry of said second parameter for the same said information item to enable operation or further operation of the main program material.

2. The combination of claim 1, wherein said basis for said identification is unpredictable from one machine-loading to another of program material from said carrier.

3. The combination according to claim 1, wherein the separate record correlates multiple colour codes as said second parameters with pointers or labels as said first parameter.

4. The combination according to claim 3, wherein the multiple colour codes are in a grid arrangement and the pointers or labels are row and column identifiers.

5. The combination according to claim 1, wherein said further or incorporated program material causes all program material machine-loaded from said carrier to be wiped from store unless the correct second parameter is operator-entered within a prescribed number of attempts.

6. In combination with a computer, the combination according to claim 1.

7. A computer security system and/or program carrier arranged and adapted to operate substantially as herein described and as shown in the accompanying drawings.