Disclosed are an electronic apparatus and a control method thereof. According to the present disclosure, an electronic apparatus with N-bit hardware architecture includes a memory configured to store a scaling factor, and a processor configured to obtain a homomorphic encrypted message with an M*N-bit word size, and perform an operation on the homomorphic encrypted message using the scaling factor. In this case, the M is an integer of 2 or more, and the scaling factor is composed of M prime numbers.