Patent ID: 7602909

Claim:
A method of operating an ATM, comprising: a) maintaining modules within the ATM; b) prior to a communication between two modules, performing encryption which generates templates in modules, such that i) the templates in a first pair of modules are identical to each other; ii) the templates in a second pair of modules are identical to each other; iii) the templates in the first pair are different from the templates in the second pair; c) when a communication is required between modules, i) generating a message in an originating module, ii) encrypting the message using a template as a key, to produce an encrypted message, and iii) transmitting the encrypted message to another module; and d) if no communication is required between modules, maintaining the templates generated in paragraph (b) until a communication is required and then, after the communication completes, changing the templates in the modules involved in the communication.