COMPUTING APPARATUS AND METHOD OF INTEGRATING DIFFERENT HOMOMORPHIC OPERATIONS IN HOMOMORPHIC ENCRYPTION

A method of integrating different homomorphic operations in homomorphic encryption is provided. The method includes receiving a homomorphic ciphertext and encryption scheme information from a ciphertext generating apparatus by using a communication interface, performing a homomorphic multiplication operation on the homomorphic ciphertext by using a homomorphic multiplication operator, analyzing the encryption scheme information to determine one operation of a re-linearization operation performed by a re-linearization operator and a key switching operation performed by a key switching operator by using a main controller, performing the determined one operation by using the re-linearization operator or the key switching operator, and performing a modulus switching operation on an operation result of the determined one operation by using a modulus switching operator.