A system on chip is provided. The system on chip includes a first memory to store a plurality of encryption keys, a second memory, a third memory to store an encryption key setting value, and a CPU to decrypt encrypted data which is stored in an external non-volatile memory using an encryption key corresponding to the encryption key setting value from among the plurality of encryption keys, to store the decrypted data in the second memory, and to perform a boot using data stored in the second memory. Accordingly, security of a boot operation can be improved.