Encryption in a secure computerized gaming system

• US 20030014639A1
• Filed: 07/25/2002
• Published: 01/16/2003
• Est. Priority Date: 03/08/2001
• Status: Active Grant

• Current Assignee: IGT (International Game Technology)
• Original Assignee: IGT (International Game Technology)
• Inventors: Jackson, Mark D, Martinek, Michael G
• Granted Patent: US 7,203,841 B2
• Time in Patent Office: Days
• US Class Current: 713/181
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 2221/2109 Game systems
• CPC Class Codes: G07F 17/32 for games, toys, sports, or amusements
• CPC Class Codes: G07F 17/3241 Security aspects of a gaming system, e.g. detecting cheating, device integrity, surveillance computer security G06F21/00
• CPC Class Codes: H04L 2209/56 Financial cryptography, e.g. electronic payment or e-cash
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

The present invention provides an architecture and method for a gaming-specific platform that features secure storage (354) and verification (366) of game code and other data, provides the ability to securely exchange data with a computerized wagering gaming system, and does so in a manner that is straightforward and easy to manage. Some embodiments of the invention provide the ability to identify game program code as certified or approved, such as by the Nevada Gaming Regulations Commission or other regulatory agency. The invention provides these and other functions by use of encryption (216), including digital signatures (220) and hash functions (210) as well as other encryption methods.

Claims

1. A computerized wagering game apparatus, comprising:

a computerized game controller having a processor, memory, and nonvolatile storage and operable to control the computerized wagering game; and

game data stored in the nonvolatile storage, wherein the game data stored in nonvolatile storage is verified during operation.

2. The computerized wagering game apparatus of claim 1, wherein the game data securely stored in the nonvolatile storage is hashed with a one-way hash function and a resulting hash value is compared to a reference hash value to ensure that the gaming program has not changed since calculation of the reference hash value.

3. The computerized wagering apparatus of claim 2, wherein the game data is hashed after loading the gaming program into random access memory and the resulting hash value is compared to a reference hash value in a continuously executing program thread executing on the computerized game controller.

4. The computerized wagering game apparatus of claim 2, wherein the computerized wagering game system is brought to a tilt state if the resulting hash value is not the same as the reference hash value.

5. The computerized wagering game apparatus of claim 2, wherein the reference hash value is stored in a nonvolatile memory comprising a part of the computerized wagering game apparatus.

6. The computerized wagering game system of claim 1, wherein a system handler application loads and executes encryption functions which are subsequently used to securely load other game data from nonvolatile storage.

7. The computerized wagering game apparatus of claim 1, wherein the game data securely stored in the nonvolatile storage via encryption is signed with a digital signature.

8. The computerized wagering game apparatus of claim 7, wherein the digital signature comprises encryption of the gaming program data with a signer'"'"'s private key.

9. The computerized wagering game apparatus of claim 8, further comprising a nonvolatile memory storing a public key corresponding to the signer'"'"'s private key.

10. The computerized wagering game apparatus of claim 7, wherein the digital signature comprises encryption with a signer'"'"'s private key of a hash value produced by hashing the gaming program data with a one-way hash function.

11. The computerized wagering game apparatus of claim 10, further comprising a nonvolatile memory storing a public key corresponding to the signer'"'"'s private key.

12. The computerized wagering game apparatus of claim 7, wherein the gaming program data signed with a digital signature is signed with a digital signature from a regulatory organization, thereby signifying organization approval of the gaming program data.

13. The computerized wagering game apparatus of claim 1, wherein the computerized game controller is a general-purpose computer.

14. The computerized wagering game apparatus of claim 12, wherein the general-purpose computer is an IBM PC-compatible computer.

15. The computerized wagering game apparatus of claim 1, further comprising a network interface connecting the computerized wagering game apparatus to a networked computer.

17. The method of claim 16, further comprising encryption of data communicated via the computerized wagering game apparatus over a network.

18. The method of claim 17, wherein the data communicated over the network comprises instructions to control the operation of the computerized wagering game.

19. The method of claim 17, wherein the data communicated over the network comprises shared objects for execution on the computerized wagering game.

20. The method of claim 17, wherein the data communicated over the network comprises data reported by the computerized wagering game.

21. The method of claim 16, wherein encryption of data stored in the computerized gaming apparatus comprises:

hashing the stored data with a one-way hash function; and

comparing a resulting hash value to a reference hash value to ensure that the data has not changed since calculation of the reference hash value.

22. The method of claim 21, wherein the reference hash value is stored in nonvolatile memory that comprises a part of the computerized wagering game apparatus.

23. The method of claim 16, wherein hashing the stored data with a one-way hash function comprises:

loading the data into random access memory;

hashing the stored data with a one-way hash function in a continuously executing thread; and

comparing a resulting hash value to a reference hash value in a continuously executing thread to ensure that the data has not changed since calculation of the reference hash value.

24. The method of claim 21, further comprising bringing the computerized wagering game to a tilt state if the resulting hash value is not the same as the reference hash value.

25. The method of claim 16, wherein encryption of data stored in the computerized gaming apparatus comprises signing the data with a digital signature.

26. The method of claim 25, wherein signing the data with a digital signature comprises encryption of the data with a signer'"'"'s private key.

27. The method of claim 26, wherein a public key corresponding to the signer'"'"'s private key is stored in nonvolatile memory comprising a part of the computerized wagering game apparatus.

28. The method of claim 26, wherein signing the data with a digital signature comprises:

computing a hash value from the data produced with a one-way hash function; and

encrypting the hash value with a signer'"'"'s private key.

29. The method of claim 28, wherein a public key corresponding to the signer'"'"'s private key is stored in nonvolatile memory comprising a part of the computerized wagering game apparatus.

30. The method of claim 16, wherein the computerized wagering game apparatus comprises a general-purpose computer.

31. The method of claim 30, wherein the general-purpose computer comprises an IBM PC-compatible computer.

32. The method of claim 16, wherein encrypting data comprises use of a symmetric encryption algorithm to encrypt data.

16. A method for securing data on a computerized wagering game apparatus, comprising verification of game data located in RAM during operation of a computerized gaming apparatus.

33. A machine-readable medium with instructions stored thereon, the instructions when executed operable to cause a computerized wagering game apparatus to:

apply encryption to data stored in the computerized gaming apparatus.

34. The machine-readable medium of claim 33, further comprising instructions that when executed are further operable to cause the computerized wagering game apparatus to:

apply encryption to data communicated via the computerized wagering game apparatus over a network.

35. The machine-readable medium of claim 33, wherein applying encryption to data stored in the computerized gaming apparatus comprises:

hashing the data with a one-way hash function; and

comparing a resulting hash value to a reference hash value to ensure that the data has not changed since calculation of the reference value.

36. The machine-readable medium of claim 33, wherein applying encryption to data stored in the computerized gaming apparatus comprises signing the data with a digital signature.

37. The machine-readable medium of claim 36, wherein signing the data with a digital signature comprises encryption of the data with a user'"'"'s private key.

38. The machine-readable medium of claim 36, wherein signing the data with a digital signature comprises:

computing a hash value from the data produced with a one-way hash function; and

encrypting the hash value with a signer'"'"'s private key.

39. A computerized wagering game apparatus, comprising:

a computerized game controller having a processor, memory and nonvolatile storage and operable to control the computerized wagering game;

gaming program code and gaming program code signature stored in the nonvolatile storage, and

an authentication program stored in nonvolatile storage, wherein the authentication program, when executed, verifies that the gaming program code in nonvolatile storage has not changed by means of generating a message digest from the gaming program code, decrypting the message digest using a first decryption program;

decrypting the gaming program code signature with a second decryption program and comparing the two decrypted messages to verify that they are identical.

40. A method of preparing a game data set capable of authentication comprising:

providing a game data set;

determining a message authentication code unique to the game data set; and

storing the game data set and the message authentication code.

41. The method of claim 40, further comprising:

defining a key; and

using the key to determine the message authentication code unique to the game data set.

42. The method of claim 41, further comprising:

storing the key with the game data set and the message authentication code.

43. The method of claim 40, further comprising:

defining the game data set to include a set of program files, and wherein determining the message authentication code unique to the game data set includes determining a message authentication code unique to each program file in the program file set.

44. The method of claim 40, further comprising:

defining a key;

defining a message authentication code function;

determining the message authentication code unique to the game data set by applying the game data set and the key to the message authentication code function.

45. A method of claim 40, further comprising:

defining a key;

defining the game data set to include a set of program files, the set of program files including a first game program file and a second game program file;

defining a message authentication code function; and

determining a first message authentication code unique to the first game program file by applying the first game program file and the key to the message authentication code function; and

determining a second message authentication code unique to the second game program file by applying the second game program file and the first message authentication code to the message authentication code function.

46. The method of claim 45, further comprising:

defining the game data set to include N game program files;

determining an N message authentication code unique to an N program file by applying the N program file and a last determined message authentication code to the message authentication code function.

47. The method of claim 46, wherein the last determined message authentication code is the second message authentication code.

48. The method of claim 46, further comprising:

determining a first prime message authentication code for the first game program file by applying the first game program file and the N message authentication code to the message authentication code function.

50. The method of claim 49 wherein the step of using the control file to verify authentication of the game comprises:

determining a complimentary message authentication code set including a complementary message authentication code unique to each program file in the set of program files using the set of program files and the message authentication code key; and

comparing the message authentication code set to the complimentary message authentication code set to verify authentication of the game.

51. The method of claim 50, wherein if the message authentication code set and the complimentary message authentication code set match, further comprising indicating that the game is verified authentic.

52. The method of claim 50, wherein if the message authentication code set and the complimentary message authentication code set do not match, indicating that the game is not verified authentic.

53. The method of claim 49 further comprising:

receiving the control file, including the set of program files, the set of message authentication codes including the message authentication code unique to each program file, and the message authentication code key;

encrypting the control file to provide the encrypted control file;

storing the encrypted control file.

54. The method of claim 53, further comprising using a private key to encrypt the control file.

55. The method of claim 53, further comprising using a public key to encrypt the control file.

56. The method of claim 49, further comprising decrypting the encrypted control file using a public key.

57. The method of claim 49, further comprising generating the control file including:

providing a game data set including the set of program files;

defining the message authentication code key;

determining the message authentication code unique to the game data set using the game data set and the message authentication code key, including determining the message authentication code unique to each program file; and

storing the set of program files, the message authentication codes, and the message authentication code key as the control file.

59. The system of claim 58, wherein the control file is an encrypted control file, and wherein the controller operates to decrypt the encrypted control file to provide the control file.

60. The system of claim 58, wherein the game controller include volatile memory, and wherein the game controller operates to authenticate the game data set each time the game data set is transferred from the nonvolatile memory to volatile memory for use by the gaming system.

49. A method of authenticating a game used in a gaming system comprising:

receiving an encrypted control file,

decrypting the encrypted control file to provide a control file, the control file including a set of program files, a set of message authentication codes including a message authentication code unique to each program file, and a message authentication code key; and

using the original control file to verify authentication of the game.

58. A gaming system comprising:

a nonvolatile memory;

a control file stored in the nonvolatile memory, the control file including a game data set, a message authentication code unique to the game data set, and a message authentication code key; and

a game controller, wherein the game controller operates to selectively authenticate the game data set using the message authentication code unique to the game data set during operation of the gaming system.

61. A gaming system comprising:

a nonvolatile memory;

an encrypted control file stored in the nonvolatile memory, the encrypted control file including a set of program files, a message authentication code unique to each program file, and a message authentication code key;

a gaming controller, wherein the gaming controller operates to decrypt the encrypted control file and authenticate the gaming program files during operation of the gaming system; and

gaming system devices in communication with the gaming controller via a gaming system interface.

62. The system of claim 61, further comprising a message authentication code process stored in memory, wherein the game controller authenticates the set of program files by applying the message authentication process using the set of program files and the message authentication code key to provide a set of complimentary message authentication codes, and comparing the message authentication codes from the control file to the complimentary message authentication codes.

63. The system of claim 62, wherein the message authentication process is stored in read only memory.

64. The system of claim 61, wherein the nonvolatile memory is writeable memory.

65. The system of claim 64, wherein the nonvolatile memory is flash memory.

66. A computer-readable medium having computer-executable instructions for performing a method of preparing a game data set capable of authentication comprising:

providing a game data set;

determining a message authentication code unique to the game data set; and

storing the game data set and the message authentication code.

69. The method of claim 68, wherein if the stored hashed output matches the complimentary hashed output, continuing to verify the game data set.

70. The method of claim 68, wherein if the stored hashed output does not match the complimentary hashed output, terminating operation of the game.

67. A computer-readable medium having computer-executable instructions for performing a method of authenticating a game used in a gaming system comprising:

receiving an encrypted control file;

decrypting the encrypted control file to provide a control file, the control file including a set of program files, a set of message authentication codes including a message authentication code unique to each program file, and a message authentication code key; and

using the original control file to verify authentication of the game.

68. A method of continuously verifying a game used in a gaming system comprising:

receiving a game data set;

determining a hashed output unique to the game data set;

storing the hashed output;

determining a complimentary hashed output unique to the game data set during operation of the game;

comparing the stored hashed output to the complimentary hashed output.