Gaming machine having a secure boot chain and method of use

Abstract

An electronic gaming machine (EGM) comprises a memory storing boot program code comprising first 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.

1 . An electronic gaming machine (EGM) comprising:
 a central processing unit (CPU) arranged to initiate a boot process using first code; and   a monitoring device having 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 CPU executes the first code, the CPU calculates a hash of a second code and compares the calculated hash to a pre-calculated hash and proceeds if the hashes match; and   wherein when executed by the CPU, the CPU calculates a hash of a third code, compares the hash to a stored hash of the third code, 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 a 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 any of the hashes do not match. 
     
     
         7 . An EGM as claimed in  claim 1  wherein a memory stores the first, second, and third codes, and wherein said memory 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 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. 
 
     
     
         10 . An EGM as claimed in  claim 9  wherein the authentication data is a certificate comprising the public key and identity data. 
     
     
         11 . A method of protecting an electronic gaming machine comprising:
 initiating a boot process;   reading first, second, and third codes from a memory in response to initiating the boot process;   calculating a hash of the second code;   comparing the calculated hash to a pre-calculated hash of the second code;   in response to the calculated hash of the second code matches the pre-calculated hash, calculating a hash of the third code;   comparing the calculated hash of the third code to a pre-calculated hash of the third code; and   in response to the calculated hash of the third code does not match the pre-calculated hash of the third code, taking at least one protective action.   
     
     
         12 . A method as claimed in  claim 11 , comprising comparing the first code read by the CPU to the validation code. 
     
     
         13 . A method as claimed in  claim 11  comprising comparing the first code to the validation code prior to the first code being read by the CPU. 
     
     
         14 . A method as claimed in  claim 11  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. 
 
     
     
         15 . A method as claimed in  claim 14  wherein the authentication data is a certificate comprising the public key and identity data.