Gaming machine having a secure boot chain and method of use

1. An electronic gaming machine (EGM) comprising:

a memory storing boot program code comprising first code, second code and third code;

a central processing unit (CPU) arranged to access the memory and initiate a boot process by reading the first code from the memory; and

a monitoring device having or with access to validation code and arranged to take at least one protective action if the first code does not match the validation code,

wherein the first code comprises a hash algorithm and a pre-calculated hash of the second code, the first code being arranged such that when the CPU executes the first code, the CPU calculates a hash of the second code and compares the calculated hash to the pre-calculated hash and proceeds if the hashes match; and

wherein the third code comprises a master private key signature of a pre-calculated hash of the third code, and the second code comprises a master public key and a decryption algorithm, the second code being arranged such that when executed by the CPU, the CPU calculates a hash of the third code, decrypts the signature with the master public key to obtain the pre-calculated hash, compares the two hashes and proceeds if the hashes match.

2. An ERM as claimed in claim 1 , wherein the EGM is arranged to monitor reading of the first code by the CPU.

3. An EGM as claimed in claim 1 wherein the monitoring device is arranged to access the memory prior to the memory being accessed by the EGM.

4. An EGM as claimed in claim 1 wherein the monitoring device stores the validation code.

5. An EGM as claimed in claim 1 wherein the protective action is that the monitoring device causes the EGM to terminate or fail booting.

6. An EGM as claimed in claim 1 wherein execution halts if the hashes do not match.

7. An EGM as claimed in claim 1 wherein the memory storing the boot program code is read only.

8. An EGM as claimed in claim 1 further comprising a further memory comprising a signature of one or more external BIOS hashes, and the third code is arranged such that the CPU verifies each external BIOS hash before transferring control to any of the one or more external BIOSes.

9. An EGM as claimed in claim 1 wherein the third code is arranged such that the CPU verifies the active boot partition on the active boot device by generating a hash of the boot partition and comparing it to a hash stored on the active boot device before transferring control to the master boot record of the active boot partition.

10. An electronic gaming machine (EGM) as claimed in claim 1 further comprising:

a removable memory device in data communication with the CPU and storing authentication data comprising a public key, the CPU arranged to access the memory and initiate a boot process by reading the boot program code from the memory, the boot process including authenticating at least one set of code to be executed by the EGM by retrieving and employing the authentication data from the removable memory device.

11. An EGM as claimed in claim 10 wherein the authentication data is a certificate comprising the public key and identity data.

12. A method of protecting an electronic gaming machine comprising:

storing boot program code comprising first code in a memory, second code and third code; and

monitoring initiation of a boot process in which a central processing unit reads the first code from the memory by comparing the first code read by the CPU to validation code; and

taking at least one protective action if the read first code does not match the validation code,

wherein the first code comprises a pre-calculated hash of the second code, and the method comprises calculating a hash of the second code and comparing it to the pre-calculated hash and proceeding if the hashes match; and

wherein the third code comprises a master private key signature of a pre-calculated hash of the third code, the second code comprises a master public key (MPK), and the method comprises calculating a hash of the third code, decrypting the signature to obtain the pre-calculated hash, comparing the two hashes and proceeding if the hashes match.

13. A method as claimed in claim 12 , comprising comparing the first code read by the CPU to the validation code.

14. A method as claimed in claim 12 comprising comparing the first code to the validation code prior to the first code being read by the CPU.

15. A method as claimed in claim 12 comprising:

storing authentication data in a removable memory; and

initiating a boot process in which a central processing unit reads the boot program code from the memory, the boot process including authenticating at least one set of code to be executed by the EGM by retrieving and employing the authentication data from the removable memory.

16. A method as claimed in claim 15 wherein the authentication data is a certificate comprising the public key and identity data.