AU2011211454A1 - A storage method for a gaming machine - Google Patents

Abstract

Abstract An authentication method for a gaming machine, comprising: starting the gaming machine; performing an initial s authentication of program code comprising at least a first category and a second category during start up of the gaming machine, the first category of program code being program code that is expected to be modified more frequently than the second category of program code, the 10 first and second categories of program code being stored in logically separate storage areas, the initial authentication being performed by authenticating the storage areas in which the first and second categories of program code are stored, the initial authentication is comprising calculating at least one cumulative hash, and verifying the at least one cumulative hash against a digitally signed cumulative hash using a master public key; receiving modifying program code; determining which category the modifying program code belongs to and storing 20 the modifying program code in the storage area corresponding to the category; and authenticating the storage area in which the modifying program code is stored prior to executing the modifying program code. 2775115_1 (GHMatters) P71108.AU.3 15/08/11 04' 00 0O g< w z

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant: Aristocrat Technologies Australia Pty Limited Invention Title: A STORAGE METHOD FOR A GAMING MACHINE The following statement is a full description of this invention, including the best method for performing it known to me/us: -2 Title A STORAGE METHOD FOR A GAMING MACHINE 5 Related Application This application is a divisional application of Australian application no. 2010238556, the disclosure of which is incorporated herein by reference. Most of the disclosure 10 of that application is also included herein, however, reference may be made to the specification of application no. 2010238556 as filed or accepted to gain further understanding of the invention claimed herein. 15 Field The present invention relates to a storage method for a gaming machine, a gaming machine, and a gaming system. 20 Background Gaming machines must meet high standards of security in order to obtain regulatory approval. This 25 presents challenges in an environment where aspects of the gaming machine may be modified dynamically. The present invention addresses one of those challenges. Summary of the Invention 30 In a first aspect the invention provides an authentication method for a gaming machine, comprising: starting the gaming machine; performing an initial authentication of program 35 code comprising at least a first category and a second category during start up of the gaming machine, the first category of program code being program code that is 27751 15_1 (GHMatters) P71 108.AU.3 15/08/11 -3 expected to be modified more frequently than the second category of program code, the first and second categories of program code being stored in logically separate storage areas, the initial authentication being performed by s authenticating the storage areas in which the first and second categories of program code are stored, the initial authentication comprising calculating at least one cumulative hash, and verifying the at least one cumulative hash against a digitally signed cumulative hash using a 10 master public key; receiving modifying program code; determining which category the modifying program code belongs to and storing the modifying program code in the storage area corresponding to the category; and 15 authenticating the storage area in which the modifying program code is stored prior to executing the modifying program code. In an embodiment, each logically separate storage 20 area is also authenticated at least each time the gaming machine is booted. Depending on the embodiment a modification may comprise an addition of program code to the storage area, 25 replacement of program code to the storage area, or an update to program code to the storage area. In an embodiment, the first category of program code is game code. 30 In an embodiment, there are three categories of program code stored in logically separate storage areas to one another, game code, core code and system code. 35 In an embodiment, there are three logically separate storage areas. In an embodiment, the logically separate storage areas are on the same storage medium. 2775115_1 (GHMatters) P71 8AU.3 15/08/11 - 4 In some embodiments, one or more categories of program code may be stored in a plurality of logically separate storage areas separate to the storage areas of s other categories. The storage medium may be compact flash, a hard drive or other data storage medium. 10 In a second aspect the invention provides an electronic gaming machine, comprising: one or more storage mediums arranged into at least two logically separate storage areas, including a first storage area and a second storage area, the first is area being allocated to a first category of program code that is expected to be modified more frequently than a second category of program code stored in the second storage area, the gaming machine arranged to: perform an initial authentication of program code 20 comprising at least a first category by authenticating the storage areas in which the first and second categories of program code are stored, the initial authentication comprising calculating at least one cumulative hash, and verifying the at least one cumulative hash against a 25 digitally signed cumulative hash using a master public key; receive modifying program code; determine which category the modifying program code belongs to and store the modifying program code in 30 the storage area corresponding to the category; and authenticate the storage area in which the modifying program code is stored prior to executing the modifying program code. 35 In an embodiment, the electronic gaming machine comprises an authenticator arranged to authenticate program code in response to modification of a storage 2775115_1 (GHMatters) P71108.AU.3 1508/11I - 5 area, the authentication being performed prior to executing the modified program. In an embodiment, the gaming machine is adapted 5 to receive modifying program code from one or more content servers. Depending on the embodiment, the modifying program code may add to existing program code, replace 10 existing program code and/or update existing program code. In a third aspect the invention provides a gaming system, comprising: a electronic gaming machine, comprising: 15 one or more storage mediums arranged into at least two logically separate storage areas, including a first storage area and a second storage area, the first area being allocated to a first category of program code that is expected to be modified more frequently than a 20 second category of program code stored in the second storage area, the gaming machine arranged to: perform an initial authentication of program code comprising at least a first category by authenticating the storage areas in which the first and second categories of 25 program code are stored, the initial authentication comprising calculating at least one cumulative hash, and verifying the at least one cumulative hash against a digitally signed cumulative hash using a master public key; 30 receive modifying program code; determine which category the modifying program code belongs to and store the modifying program code in the storage area corresponding to the category; and authenticate the storage area in which the 35 modifying program code is stored prior to executing the modifying program code; and at least one content server in data communication 2775115_1 (GHMatters) P71 108AU.3 15/08/11 - 6 with the gaming server and adapted to provide modifying program code to the gaming machine. Depending on the embodiment, the modifying 5 program code may add to existing program code, replace existing program code and/or update existing program code. Depending on the embodiment the modifying program code may be pulled from the content server or pushed to 10 the gaming machine or a combination of push and pull depending on, for example, a characteristic of the program code. For example, gaming code may be pulled whereas system code may be pushed. 15 Brief Description of the Invention An exemplary embodiment of the invention will now be described in relation to the following drawings in which: 20 Figure 1 is a perspective view of a gaming machine; Figure 2 is a schematic diagram of the main components of the gaming machine that relate to 25 implementation of the security method; and Figure 3 shows a flow chart of the method of the embodiment. 30 Detailed Description Referring to the drawings, there is shown a gaming system incorporating an electronic gaming machine arranged to implement a storage method in which program 35 code is categorized and program code of different categories is stored in logically separate storage areas ("partitions"). 2775115_1 (GHMatters) P71108.AU.3 15/08/11 - 7 A gaming machine 10 is illustrated in Figure 1. The gaming machine 10 includes a console 12 having a display 14 on which is displayed representations of a game 5 16 that can be played by a player. A mid-trim 20 of the gaming machine 10 houses a bank of buttons 22 for enabling a player to interact with the gaming machine, in particular during game play. The mid-trim 20 also houses a credit input mechanism 24 which in this example includes 10 a coin input chute 24A and a bill collector 24B. Other credit input mechanisms may also be employed, for example, a card reader for reading a smart card, debit card or credit card. A reading device may also be provided for the purpose of reading a player tracking device, for 15 example as part of a loyalty program. The player tracking device may be in the form of a card, flash drive or any other portable storage medium capable of being read by the reading device. 20 A top box 26 may carry artwork 28, including for example pay tables and details of bonus awards and other information or images relating to the game. Further artwork and/or information may be provided on a front panel 29 of the console 12. A coin tray 30 is mounted 25 beneath the front panel 29 for dispensing cash payouts from the gaming machine 10. The display 14 shown in Figure 1 is in the form of a video display unit, particularly a cathode ray tube 30 screen device. Alternatively, the display 14 may be a liquid crystal display, plasma screen, any other suitable video display unit, or the visible portion of an electromechanical device. The top box 26 may also include a display, for example a video display unit, which may be 35 of the same type as the display 14, or of a different type. 2775115_ 1 (GHManers) P71108.AU3 15/08/11 -8 As illustrated in Figures 2, a gaming system 200 has a electronic gaming machine 220 having a central processing unit (CPU) 240 and a content server 260. Figure 2 illustrates the embodiment in respect of an example of a 5 single electronic gaming machine and a single content server. A person skilled in the art will appreciate that in practice that there will be a plurality of electronic gaming machines each in data communication with a content server and that there may be a number of different 10 configurations of the content server. For example, there may be a plurality of content servers providing the same content or there may be a content servers dedicated to specific content. For example, Figure 2 shows the content server having two separate functions of an update 15 controller 270 and a game request handler 280 which could be handled by separate content servers. Referring to Figure 2, the electronic gaming machine 220 has a storage medium 230 and stores code in 20 three separate partitions 231,232,233. In the embodiment the code is divided into three categories, core code stored in a core code partition 231, which contains commercially available software under general public licence (which may be modified to some extent to suit a 25 gaming environment); system code stored in a system code partition 232 which contains gaming specific device drivers, an audio visual library, an emulator, communication software and market related modules of software; and game code stored as one or more game code 30 packages in a game code partition 233 which provides game logic, mathematics and multimedia resources required for a specific game to be played on the electronic gaming machine. 35 The CPU 240 executes an authentication function 244. Prior to execution of any of the code 231, 232, 233, the authenticator 244 authenticates this code. 2775115_I (GHMatters) P71 08.AU.3 S/08/11 -9 The CPU also executes a data modification controller function 242 which determines whether any of the code in the storage medium 230 is to be modified, 5 controls the updating, removal, replacement or addition to that code and also ensures that if there is any modifying code received that this results in the authenticator 244 authenticating the program code that modified the partition prior to execution of that program code. In the 10 embodiment it is envisaged that code will be modified in two ways. A first form of modification arises because the size of the storage medium inherently impose limits on the 15 amount of software that can be stored thereon. The storage medium may be compact flash, a hard drive or similar. Accordingly, it is envisaged that not all games playable on the gaming machine 220 will be stored on the gaming machine. Therefore, the player interface 250 of 20 the electronic gaming machine 220 includes a game request input mechanism 252 to allow the player to select a game which is not be currently resident in the game code 233 of the gaming machine 220. This game request is sent from the player interface 250 to the data modification 25 controller 242 which will pull the requested game from the content server 260. A game request handler 280 of the content server 260 obtains the game code from a game code database 282 30 and sends it to the gaming machine 220 as a game code package. The data modification controller 242 determines that this game code package is to be written to the game code partition 233, writes the code to the game code partition 233 and advises the authenticator 244 that the 35 game code partition 233 has been modified. The authenticator then authenticates the game code package 233 prior to the CPU executing the game code and allowing the 2775115_1 (GHMatters) P71OSAU.3 15/08/11 - 10 player to play the game specified by the game code. In a variation of the above embodiment, the authenticator authenticates all software packages in a 5 partition if any modification is made to the partition. In an example, this may be done by re-authenticating the entire partition. Accordingly, code such as game code which is 10 expected to be modified more frequently than other code can be stored in a separate partition or partitions to other code. A person skilled in the art will appreciate that the core code or system code would not necessarily need to be kept in separate partitions. However there are 15 some commercial advantages in keeping system specific code separate from general purpose code. In particular, keeping this code separate allows it to be approved by regulators in isolation of approval of the game code and also in isolation of one another. 20 The second form of code modification which is anticipated is where it is determined code contained within the gaming machine and in particular core and system code requires an update or a patch. Thus, the 25 update controller 270 may determine based on a current machine status stored in a database 276 that a particular electronic gaming machine needs an update of components of core and system code 272, 274. The update controller pushes this data to the data modification controller 242 30 which recognises that both the core 231 and system 232 code requires modification. The data modification controller writes the updated program code to the partitions that hold the core and system code and advises (or launches) the authenticator to have it authenticate 35 the modified partition. A person skilled in the art will appreciate that 27751 15_ (GHMatters) P71 108 AU3 15/08/11 - 11 in some embodiments there may be more than the three partitions outlined above. For example, two partitions for game code and one for each of system and core code. 5 The method is shown in more detail in Figure 3. A step 310 the program code is stored in three partitions. Start up occurs at step 320 following which the code of all partitions is authenticated 330. During the start up process, a master public key is made available to the CPU. 10 Manifest files are provided for the core code, the system code and each game code package. For example, there may be a Game A package and a Game B package. Each manifest file contains a list of files contained in the package and a DSA signed cumulative hash of the files, signed with a 15 master private key. The CPU checks that all listed files are present, calculates a HMAC SHA-1 hash of each listed file, calculates a cumulative hash and verifies the cumulative hash against the digitally signed cumulative hash using the master public key. At step 350 modifying 20 code is received. As described above, this may be as a result of an update being determined by a content server or as a result of a player request to a game 340. At step 360 the method involves determining which partition needs to be updated and the code is written to the partition at 25 step 370. The code written to the modified partition will have a manifest file with a cumulative hash and is authenticated 380 using the same technique described above, prior to execution of code from the partition 390. 30 Persons skilled in the art will appreciate that there maybe variations to the authentication technique. For example, while the above embodiment employs SHA-1 hashes and DSA signatures, other cryptographic hashes and encryption techniques may be employed, for example RSA or 35 ECC. These and other variations will be apparent to 2775115_1 (GHMaters) P71 108AU.3 15/08/11 - 12 persons skilled in the art and should be considered as falling within the invention described herein. In the claims which follow and in the preceding 5 description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but 10 not to preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not 15 constitute an admission that the publication forms a part of the common general knowledge in the art, in any country. 20 2775115_1 (GHMatters)P71108AU.3 15/08/11

Claims (28)

1. An authentication method for a gaming machine, comprising: s starting the gaming machine; performing an initial authentication of program code comprising at least a first category and a second category during start up of the gaming machine, the first category of program code being program code that is 10 expected to be modified more frequently than the second category of program code, the first and second categories of program code being stored in logically separate storage areas, the initial authentication being performed by authenticating the storage areas in which the first and 15 second categories of program code are stored, the initial authentication comprising calculating at least one cumulative hash, and verifying the at least one cumulative hash against a digitally signed cumulative hash using a master public key; 20 receiving modifying program code; determining which category the modifying program code belongs to and storing the modifying program code in the storage area corresponding to the category; and authenticating the storage area in which the 25 modifying program code is stored prior to executing the modifying program code.

2. A method as claimed in claim 1, wherein a modification comprises one or more of an addition of 30 program code to the storage area, replacement of program code to the storage area, or an update to program code to the storage area.

3. A method as claimed in claim 1 or claim 2, 35 wherein the first category of program code is game code.

4. A method as claimed in any one of claims 1 to 3, 2775115_1 (GHManers)P71 108.AU.3 15/08/11 - 14 wherein there are three categories of program code stored in logically separate storage areas to one another: game code, core code and system code.

5 5. A method as claimed in any one of claims 1 to 4, wherein there are three logically separate storage areas.

6. A method as claimed in any one of claims 1 to 5, wherein the logically separate storage areas are on the 10 same storage medium.

7. A method as claimed in any one of claims 1 to 6, wherein one or more categories of program code is stored in a plurality of logically separate storage areas 15 separate to the storage areas of other categories.

8. An electronic gaming machine, comprising: one or more storage mediums arranged into at least two logically separate storage areas, including a 20 first storage area and a second storage area, the first area being allocated to a first category of program code that is expected to be modified more frequently than a second category of program code stored in the second storage area, the gaming machine arranged to: 25 perform an initial authentication of program code comprising at least a first category by authenticating the storage areas in which the first and second categories of program code are stored, the initial authentication comprising calculating at least one cumulative hash, and 30 verifying the at least one cumulative hash against a digitally signed cumulative hash using a master public key; receive modifying program code; determine which category the modifying program 35 code belongs to and store the modifying program code in the storage area corresponding to the category; and authenticate the storage area in which the 2775115_1 (GHMatters)P71 108AU.3 15/08/11 - 15 modifying program code is stored prior to executing the modifying program code.

9. An electronic gaming machine as claimed in claim 5 8, comprising a data modification controller arranged to process the modifying program code in order to control the storage area that is modified based on the category to which the program code belongs.

10 10. An electronic gaming machine as claimed in claim 8 or claim 9, comprising an authenticator arranged to authenticate program code by authenticating one or more storage areas. 15

11. An electronic gaming machine as claimed in any one of claims 8 to 10, wherein a modification comprises one or more of an addition of program code to the storage area, replacement of program code to the storage area, or an update to program code to the storage area. 20

12. An electronic gaming machine as claimed in any one of claims 8 to 11, wherein the first category of program code is game code. 25

13. An electronic gaming machine as claimed in any one of claims 8 to 12, wherein there are three categories of program code stored in logically separate storage areas to one another: game code, core code and system code. 30

14. An electronic gaming machine as claimed in any one of claims 8 to 13, wherein there are three logically separate storage areas.

15. An electronic gaming machine as claimed in any 35 one of claims 8 to 14, the logically separate storage areas are on the same storage medium. 27751 15_I (GHMatters) P71 108.AU.3 15/08/11 - 16

16. An electronic gaming machine as claimed in any one of claims 8 to 15, wherein one or more categories of program code is stored in a plurality of logically separate storage areas separate to the storage areas of 5 other categories.

17. An electronic gaming machine as claimed in any one of claims 8 to 16, wherein the gaming machine is adapted to receive modifying program code from one or more 10 content servers.

18. A gaming system, comprising: a electronic gaming machine, comprising: one or more storage mediums arranged into at is least two logically separate storage areas, including a first storage area and a second storage area, the first area being allocated to a first category of program code that is expected to be modified more frequently than a second category of program code stored in the second 20 storage area, the gaming machine arranged to: perform an initial authentication of program code comprising at least a first category by authenticating the storage areas in which the first and second categories of program code are stored, the initial authentication 25 comprising calculating at least one cumulative hash, and verifying the at least one cumulative hash against a digitally signed cumulative hash using a master public key; receive modifying program code; 30 determine which category the modifying program code belongs to and store the modifying program code in the storage area corresponding to the category; and authenticate the storage area in which the modifying program code is stored prior to executing the 35 modifying program code; and at least one content server in data communication with the gaming server and adapted to provide modifying 277511S_l (GHMatnes) P71108.AU3 15/08/11 - 17 program code to the gaming machine.

19. A gaming system as claimed in claim 18, wherein the modifying program code is delivered to the gaming s machine by one of: a pull from the content server, a push to the gaming machine or a combination of push and pull.

20. A gaming system as claimed in claim 19, wherein the mode of delivery depends on a characteristic of the 10 program code.

21. A gaming system as claimed in claim 20, wherein gaming code is pulled and system code is pushed. 15

22. A gaming system as claimed in any one of claims 18 to 21, wherein the gaming machine comprises an authenticator arranged to authenticate program code.

23. A gaming system as claimed in any one of claims 20 18 to 22, wherein a modification comprises one or more of an addition of program code to the storage area, replacement of program code to the storage area, or an update to program code to the storage area. 25

24. A gaming system as claimed in any one of claims 18 to 23, wherein the first category of program code is game code.

25. A gaming system as claimed in any one of claims 30 18 to 24, wherein there are three categories of program code stored in logically separate storage areas to one another: game code, core code and system code.

26. A gaming system as claimed in any one of claims 35 18 to 25, wherein there are three logically separate storage areas. 2775115_1 (GHMatters) P71108 AU3 15/08/11 - 18

27. A gaming system as claimed in any one of claims 18 to 26, the logically separate storage areas are on the same storage medium. 5

28. A gaming system as claimed in any one of claims 18 to 27, wherein one or more categories of program code is stored in a plurality of logically separate storage areas separate to the storage areas of other categories. 2775115_1 (GHMatten) P71 108.AU.3 15/08/11