GB2340968A

GB2340968A - Preventing circumvention of copy protaction

Info

Publication number: GB2340968A
Application number: GB9810518A
Authority: GB
Inventors: Roger Edwards
Original assignee: C Dilla Ltd
Current assignee: Rovi Solutions Ltd
Priority date: 1998-05-15
Filing date: 1998-05-15
Publication date: 2000-03-01
Anticipated expiration: 2018-05-15
Also published as: GB9810518D0; GB2340968B

Abstract

Authentic CDs for use with a games console, such as a Sony PlayStation, are provided with copy protection information for generating authentication data to be fed to a microprocessor (4) of a CD sub-system for reading or playing the CD. Pirate CDs, which have been copied from genuine discs, do not generally have the copy protection information and this prevents the CD reader (2) of the sub-system reading or playing the pirate disc. However, there is commercially available a mod chip (10) which can be connected to the sub-system to feed a stream of data bits emulating authentication data. To prevent pirate discs being played, even when a mod chip (10) is present, differences between genuine authentication data and the bit stream provided by a mod chip are utilised to determine the presence of the mod chip. Where a mod chip is detected, operation of the games console and/or of the CD sub-system is disabled. For example, the CD reader (2) may be reset to suspend rotation of the CD. The arrival of a data stream at the microprocessor (4) during such a suspension shows the presence of a mod chip (10).

Description

2340968 PREVENTING CIRCUMVENTION OF COPY PROTECTION The prevent invention

relates to methods and systems for preventing circumvention of the copy protection of a data carrier.

The invention has been designed specifically in response to the widespread availability of a system to circumvent the copy protection provided for the Sony PlayStation JM). However, the invention would be usable not only with other game consoles but for any data carriers whose copy protection is subject to circumvention.

The Sony PlayStation uses games recorded on compact discs (CDs). Genuine CDs are copy protected and when inserted in the CD sub-system of the PlayStation the CD sub-system looks first for appropdate authentication data. If such authentication data is received and validated, then the games console is enabled to play the CD.

Pirate CDs, produced by copying originals, for example, do not generally have the necessary copy protection information to provide the authentication data when required. However, an industry has grown up for supplying devices to circumvent this lack to users of the PlayStations. When one of these devices, known as a mod chip, is connected to a PlayStation it provides authentication data and thereby enables pirate discs, without the required copy protection information, to be played.

The present invention arose out of the need to prevent the use of pirate CDs by making the mod chips ineffective. However, the present invention has utility not only specifically with the Sony PlayStation, but may be used to prevent circumvention of copy protection for any data carrier.

According to a first aspect of the present invention there is provided a method of preventing circumvention of the copy protection of a data carrier, where, for copy protection, a data accessing system is enabled to access the data on a data carrier by the receipt of authentication data, the method comprising the steps of comparing the authentication data received by the data accessing system with authentication data expected, and generating an alarm in 2 the event that the authentication data received and the authentication data expected differ.

Thus, with an embodiment of the method of the invention, differences between authentication data received and authentication data expected are used to generate an alarm. Generally, that alarm will be used to disable access to some or all of the data on the data carrier.

For example, the generation of the alarm may be used to disable the data accessing system. Alternatively, the alarm may cause the data accessing system to access only part of the data or otherwise control the manner in which the accessing system has access to the data carrier.

For example, where the data carrier is a CD and the data accessing is system is incorporated in a PlayStation or in another games console, the generation of the alarm may cause the games console to access the CD only as an audio disc.

In a preferred embodiment, the data carrier is a CD, and the data accessing system is a CID player or reader for accessing the data on the CD.

Methods of the invention may be arranged to react to one or more selected types of differences between the authentication data received and the authentication data expected. However, in a preferred embodiment, an alarm is generated in the event that authentication data is received by the data accessing system continually, periodically, or at an inappropriate time.

For example, an alarm may be generated if authentication data is received by the data accessing system when that system is not accessing data on the data carrier.

In an embodiment, a method of the invention further comprises the steps of stopping access to the data on the data carrier by the data accessing system, and generating the alarm if the arrival of authentication data is detected whilst the access to data is suspended.

3 For example, in the case of a copy protected CID provided in a CID reader or player, the method may comprise the steps of preventing access to the data on the CID, and generating an alarm in the event that authentication data is received whilst data access is prevented.

Access to the data on the CID may be prevented in any suitable manner. For example, data access may be prevented by stopping rotation of the CID and/or by turning off a laser in the CID reader to suspend reading of the CID.

For the Sony PlayStation, the arrival of authentication data whilst the reading of the CID is suspended indicates the existence of a mod chip connected to the CID reader.

Additionally and/or alternatively, the alarm is generated if the data accessing system receives authentication data whilst it is accessing program data.

For example, in an embodiment, the method further comprises the step of causing the data accessing system, whilst it is accessing program data on the data carrier, to periodically look for the arrival of authentication data.

Copy protection information of a CD for the Sony PlayStation, which generates the authentication data, is provided in the lead-in area of the CID. The CID reader of the PlayStation looks for the authentication data at start up and then enables play of the CID when that authentication data has been received. A mod chip, however, provides a stream of bits emulating the authentication data continually or frequently, and the existence of such a signal when, for example, the CID reader is reading the game program data is an indication of the existence of a mod chip.

Additionally and/or alternatively, a method of the invention is arranged to generate the alarm if the data accessing system receives identification data continually or on a number of occasions.

According to a further aspect of the present invention there is provided a method of preventing circumvention of the copy protection of a CID, where, for 4 copy protection, a CID reading system is enabled to read data on a CD by the receipt of authentication data, the method comprising the steps of resetting the CID reading system, detecting the arrival of any authentication data, and generating an alarm if any authentication data arrives continually, periodically, or at an inappropdate time.

In an embodiment, the generation of the alarm may be used to disable the CD reading system. Alternatively, the alarm may cause the CD reading system to access only part of the data or control the manner in which the reading system has access to the CD.

For example, the generation of the alarm may cause the CD reading system to access the CID only as an audio disc.

In an embodiment, an alarm may be generated if authentication data is received by the CD reading system when that system is not accessing data on the CD.

In an embodiment, the method further compdses the steps of preventing access to the data on the CD, and generating an alarm in the event that authentication data is received whilst data access is prevented.

Access to the data on the CD may be prevented in any suitable manner. For example, data access may be prevented by stopping rotation of the CD andlor by turning off a laser in the CD reader to suspend reading of the CD.

Additionally andlor alternatively, the alarm is generated if the CD reading system receives authentication data whilst it is accessing program data.

For example, in an embodiment, the method further comprises the step of causing the CD reading system, whilst it is accessing program data on the CD, to periodically look for the arrival of authentication data.

The present invention also extends to a system for preventing circumvention of the copy protection of a data carrier, where, for copy protection, a data accessing system is enabled to access the data on a data carrier by the receipt of authentication data, the circumvention prevention system comprising means for comparing the authentication data received by the data accessing system with authentication data expected, and means for generating an alarm in the event that the authentication data received differs from the authentication data expected.

In an embodiment, the circumvention prevention system comprises means responsive to the generation of the alarm for disabling the data accessing system. Alternatively, means responsive to the generation of the alarm may be arranged to cause the data accessing system to access only part of the data or control the manner in which the accessing system has access to the data carrier.

For example, where the data carrier is a CID and the data accessing system is incorporated in a PlayStation or other drive for games, the means responsive to the generation of the alarm may be arranged to cause the games console to access the CD only as an audio disc.

In a preferred embodiment, the data carrier is a CD, and the data accessing system is a CD player or reader for accessing the data on the CD.

The circumvention prevention system of the invention may be arranged to react to one or more selected types of differences between the authentication data received and the authentication data expected. However, in a preferred embodiment, said alarm generating means generates an alarm in the event that authentication data is received by the data accessing system continually, periodically, or at an inappropriate time.

In an embodiment, a circumvention prevention system of the invention further comprises means for stopping access to the data on the data carrier by the data accessing system, said alarm generating means being arranged to 1 6 generate the alarm if the arrival of authentication data is detected whilst access to the data is suspended.

For example, in the case of a copy protected CID provided in a CID reader or player, the circumvention prevention system may comprise suspension means arranged to prevent the CID reader from obtaining data from the CID, said alarm generating means being arranged to generate an alarm in the event that authentication data is received whilst the obtaining of data is prevented.

In embodiments, said suspension means may be arranged to stop rotation of the CID and/or to turn off a laser in the CID reader. Said suspension means may comprise any suitable means effective to stop or interrupt the access to the data on the CID.

Additionally and/or alternatively, the circumvention prevention system further comprises means for causing the data accessing system, whilst it is accessing data on the data carder, to pedodically look for the arrival of authentication data.

Additionally and/or alternatively, a circumvention prevention system of the invention is arranged to generate an alarm if the data accessing system receives identification data continually or on a number of occasions.

The present invention also extends to a system for preventing circumvention of the copy protection of a CID, where, for copy protection, a CID reading system is enabled to read data on a CID by the receipt of authentication data, the circumvention prevention system comprising means for causing resetting of the CID reading system, means for detecting the arrival of any authentication data after resetting, and means for generating an alarm in the event that, after the reset, authentication data arrives continually, periodically, or at an inappropriate time.

Embodiments of the present invention will hereinafter be defined, by way of example, with reference to the accompanying drawing which shows schematically a CID sub-system of a games console provided with an additional processor to circumvent copy protection.

7 A games console, such as a Sony PlayStation, has a main processor (not illustrated) and a number of sub-systems to perform various tasks. These subsystems include a CD sub-system to read or play the CD and control that process, and such a CD sub-system is illustrated schematically in the Figure.

The CD sub-system comprises a CD reader 2 providing data from a CID to a sub-system microprocessor 4 by way of a data bus 12. This microprocessor 4 is in communication with the main processor (not shown) of the games console.

The CID sub-system further includes a authentication data generator 6 connected to receive data from the CD reader 2. A gate circuit 8 enabies data from the generator 6 to be supplied to the sub-system microprocessor 4.

Each authentic CD for use with the games console is provided with copy protection. Copy protection information is generally stored in part of the lead-in to the CD. When the CID reader 2, therefore, is caused to read a newly inserted CD, the copy protection information is received by the authentication data generator 6 which is arranged to generate authentication data, in the form of a stream of bits, which is fed by way of the gate 8 to the microprocessor 4. If the authentication data received by the microprocessor 4 is recognised as valid, the microprocessor 4 recognises the CD being read by the CD reader 2 as genuine and thereafter receives from the data bus 12, and uses, data read from the CID by the reader 2.

In general, pirate CDs which have been copied from authentic CDs do not have the copy protection information enabling generation of the authentication data. Accordingly, the lack of appropriate authentication data prevents the pirate CD from being played. However, there is now commercially available a processor based device, known as a mod chip, to enable pirate CDs to be played. As is illustrated, a mod chip 10 is connected to the gate 8 of the games console to supply authentication data to the microprocessor 4. The mod chip 10 is a circuit arranged to generate a serialised stream of data bits emulating the authentication data. When, therefore, the microprocessor 4 looks to the gate 8 for authentication data, the chip 10 is effective to inject the data required. As previously, once the microprocessor 4 has received appropriate authentication data it identifies the CD in the reader 2 as valid and enables it to be read.

-) 1 8 Whilst the stream of bits injected by a mod chip 10 emulates the stream of bits which would be received by the microprocessor 4 by reading a genuine CD, there are important differences and the invention utilises the differences between genuine authentication data and the bit stream provided by a mod chip to detect the presence of the mod chip. Once a mod chip has been detected, operation of the games console andlor of the CD sub-system can be disabled.

With currently available games consoles, the CID sub-system checks for authentication data from the CD only once. The copy protection information is provided, for example, with the table of contents, at the lead-in to the CD and is read on start-up. There could be problems if the microprocessor 4 were to receive both program data from the CD and authentication data simultaneously and accordingly no authentication data is received when the program data on the CD is being read by the microprocessor 4.

This is at variance with the data provided by a mod chip as 10 which outputs its serial data stream periodically to ensure that "authentication data" is available when it is required by the microprocessor 4.

Thus, the existence of a mod chip can be detected by establishing if authentication data is available at inappropriate times, continually, or periodically.

A method of the invention looks for the existence of authentication data at times when it is known that genuine authentication data will not be available.

For example, in one method, a reset signal is issued to the CD reader 2 which is held thereby so that the CD reader 2 does not rotate, and thereby read, the CD present. If, during this suspension of rotation, the arrival of an authentication data stream is detected by the microprocessor 4, it is known that there is a mod chip 10 present.

Alternatively andlor additionally, the CD reader 2 is reset and the system waits until the reading of all of the lead-in area has been completed. The incoming data to the microprocessor 4 is then checked and the presence of authentication data after the lead-in establishes the presence of the mod chip.

9 It is also possible to look at the data input to the microprocessor 4 during normal reading of a CD by the reader 2. Again, the presence of data on the input to the microprocessor 4 by way of the gate 8 establishes the existence of a mod chip.

The detection methods described may be undertaken by the microprocessor of the CD sub-system and/or by the microprocessor (not shown) of the games console acting in response to appropriate programs. The programs may be programmed into the or each microprocessor and/or provided on each CD.

For example, the microprocessor (not shown) of the games console may be arranged to send command signals to the sub-system microprocessor 4 in order to obtain the copy protection information and data it requires. The detection method may be undertaken by making modifications to the microprocessor 4 and/or by causing the microprocessor of the games console to interrogate the microprocessor 4.

Game compilers are generally provided with a CD library by the equipment manufacturer so that the control information necessary to enable a game programmed on a CD to be played by the games console is automatically provided on the CD. The programs for the methods set out above would be incorporated in the CD library and would therefore become incorporated in the program information on each CD. Such program information is, of course, copied when pirate copies are made.

The circumvention system when incorporated on individual CDs, therefore, is difficult to circumvent because each individual CD would need to be hacked separately. The program for the circumvention prevention method may also be provided on each CD several times to make hacking even more difficult.

What is more, because the program for the circumvention prevention method is provided on each CD, it will be effective with even the oldest of the games consoles available. Accordingly, the circumvention protection method can effectively be retrospectively fitted to all games consoles.

The necessary steps for each routine for the or each circumvention prevention method as described above will be within the competence of those skilled in the art so that further details of the software routines and programs are not required. It will also be apparent that the methods can be performed by 5 hardware, or by a combination of hardware and software, as required.

It will be appreciated that variations to and modifications of the invention as specifically described may be made within the scope of this application.

Claims

1 A method of preventing circumvention of the copy protection of a data carrier, where, for copy protection, a data accessing system is enabled to S access the data on a data carrier by the receipt of authentication data, the method comprising the steps of comparing the authentication data received by the data accessing system with authentication data expected, and generating an alarm in the event that the authentication data received and the authentication data expected differ.

2. A method as claimed in Claim 1, further comprising the step of using the generation of the alarm to disable access to some or all of the data on the data carrier.

3. A method as claimed in Claim 2, wherein the generation of the alarm is used to disable the data accessing system.

4. A method as claimed in Claim 2 or Claim 3, wherein the generation of the alarm causes the data accessing system to access only part of the data.

5. A method as claimed in Claim 2, wherein the data carrier is a CD and the data accessing system is incorporated in a games console, and wherein the generation of the alarm causes the games console to access the CD only as an audio disc.

6. A method as claimed in any preceding claim, wherein an alarm is generated in the event that authentication data is received by the data accessing system continually, periodically, or at an inappropriate time.

7. A method as claimed in Claim 6, further comprising the steps of stopping access to the data on the data carder by the data accessing system, and generating the alarm if the arrival of authentication data is detected whilst the access to data is suspended.

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8. A method as claimed in Claim 6 or Claim 7, wherein the alarm is generated if the data accessing system receives authentication data whilst it is accessing program data.

9. A method as claimed in Claim 8, further comprising the step of causing the data accessing system, whilst it is accessing program data on the data carrier, to periodically look for the arrival of authentication data.

10. A method as claimed in any of Claims 6 to 9, further comprising the step of generating the alarm if the data accessing system receives identification data continually or on a number of occasions.

11. A method of preventing circumvention of the copy protection of a CD, where, for copy protection, a CID reading system is enabled to read data on a CD by the receipt of authentication data, the method comprising the steps of resetting the CD reading system, detecting the arrival of any authentication data, and generating an alarm if any authentication data arrives continually, periodically, or at an inappropriate time.

12. A method as claimed in Claim 11, further comprising the step of using the generation of the alarm to disable the CD reading system.

13. A method as claimed in Claim 11 or Claim 12, wherein the generation of the alarm causes the CD reading system to access only part of the data or to control the manner in which the reading system has access to the CD.

14. A method as claimed in Claim 13, wherein the generation of the alarm causes the CD reading system to access the CD only as an audio disc.

15. A method as claimed in any of Claims 11 to 14, further comprising the steps of preventing access to the data on the CD, and generating an alarm in the event that authentication data is received whilst data access is prevented.

16. A method as claimed in any of Claims 11 to 15, wherein the alarm is 35 generated if the CID reading system receives authentication data whilst it is accessing program data.

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17. A method as claimed in Claim 16, further comprising the step of causing the CD reading system, whilst it is accessing program data on the CD, to periodically look for the arrival of authentication data.

18. A system for preventing circumvention of the copy protection of a data carrier, where, for copy protection, a data accessing system is enabled to access the data on a data carrier by the receipt of authentication data, the circumvention prevention system comprising means for comparing the authentication data received by the data accessing system with authentication data expected, and means for generating an alarm in the event that the authentication data received differs from the authentication data expected.

19. A circumvention prevention system as claimed in Claim 18, further comprising means responsive to the generation of the alarm for disabling the data accessing system.

20. A circumvention prevention system as claimed in Claim 18 or Claim 19, wherein means responsive to the generation of the alarm are arranged to cause the data accessing system to access only part of the data or control the manner in which the accessing system has access to the data carrier.

21. A circumvention prevention system as claimed in Claim 20, where the data carrier is a CD and the data accessing system is incorporated in a games console, wherein the means responsive to the generation of the alarm is arranged to cause the games console to access the CD only as an audio disc.

22. A circumvention prevention system as claimed in any of Claims 18 to 21, wherein the system is arranged to react to one or more selected types of differences between the authentication data received and the authentication data expected.

23. A circumvention prevention system as claimed in Claim 22, wherein said alarm generating means is arranged to generate an alarm in the event that authentication data is received by the data accessing system continually, periodically, or at an inappropriate time.

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24. A circumvention prevention system as claimed in Claim 23, wherein an alarm is generated if authentication data is received by the data accessing system when that system is not accessing data on the data carrier.

25. A circumvention prevention system as claimed in Claim 24, further comprising means for stopping access to the data on the data carrier by the data accessing system, said alarm generating means being arranged to generate the alarm if the arrival of authentication data is detected whilst access to the data is suspended.

26. A circumvention prevention system as claimed in Claim 24, for use with a CID player or reader, comprising suspension means arranged to prevent the CID player or reader from obtaining data from the CD, said alarm generating means being arranged to generate an alarm in the event that authentication data is received whilst the obtaining of data is prevented.

27. A system for preventing circumvention of the copy protection of a CD, where, for copy protection, a CD reading system is enabled to read data on a CID by the receipt of authentication data, the circumvention prevention system comphsing means for causing resetting of the CID reading system, means for detecting the arrival of any authentication data after resetting, and means for generating an alarm in the event that, after the reset, authentication data arrives continually, periodically, or at an inappropriate time.

28. A method of preventing circumvention of the copy protection of a data carrier substantially as hereinbefore described with reference to the accompanying drawing.

29. A system for preventing circumvention of the copy protection of a data carrier substantially as hereinbefore described with reference to the accompanying drawing.