Patent ID: 8214632

Claim:
A method of booting an electronic device including a host Central Processing Unit (CPU) and a security module, the method comprising: starting to boot a system by using boot information by the host CPU in response to a reset or a power on event of the electronic device; determining whether or not an authentication start instruction is received from the host CPU before a first predetermined period elapses after the occurrence of the reset or the power on event of the electronic device by the security module; and if the authentication start instruction is not received by the security module from the host CPU until the first predetermined period elapses after the occurrence of the reset or the power on event of the electronic device, controlling the host CPU by the security module, wherein the security module is operable to authenticate the boot information by obtaining the boot information from a non-volatile memory of the electronic device based on a position and a size of the boot information; and wherein the security module is operable to determine a success of a boot authentication of the electronic device by: calculating a hash value from the boot information by using a hash function; obtaining a digital signature by decoding an encrypted digital signature; and determining whether or not the calculated hash value and the obtained digital signature coincide with each other.