To shorten a processing time at boot time without lowering a security level, an acquiring unit acquires a public key, a signature generated with a secret key corresponding to the public key, and a program associated with the signature. A signature verification unit performs signature verification by using the public key and the signature acquired by the acquiring unit, before the program acquired by the acquiring unit is booted. A calculation unit calculates a first MAC value by using a device eigenvalue and stores the first MAC value, when the result of signature verification by the signature verification unit is appropriate. A boot unit calculates a second MAC value by using the device eigenvalue, compares the second MAC value and the stored first MAC value with each other to determine that the program is legitimate, and executes boot based on the determination result.