Patent ID: 7587600

Claim:
A method of loading data into an electronic device, the electronic device comprising a data memory for storing data items and a key memory for storing at least one cryptographic key of a cryptographic public key mechanism, the method comprising: loading a factory public key (PuK F ) into the key memory; loading factory software signed with a factory private key (PrK F ) corresponding to the factory public key into the data memory; loading into the key memory a product public key (PuK P ) different from the factory public key for verifying subsequent data items to be loaded into the data memory after delivering the electronic device to a customer, the subsequent data items being signed with a corresponding product private key (PrK P ); and disabling the factory public key (PuK F ) prior to delivering the electronic device to the customer, wherein the loading of the product public key (PuK P ) causes the factory public key (PuK F ) to be disabled.