Functional encryption system and method of performing functional encryption

Abstract

A functional encryption system includes a key generation device configured to generate a public key and a secret key, based on a master key and a parameter vector, an encryption device configured to generate encrypted data by encrypting an input vector, based on the public key, and a decryption device configured to generate decrypted data corresponding to an approximation value of an inner product of the parameter vector and the input vector by decrypting the encrypted data based on the secret key. Security of data used in machine learning, biometric authentication, etc. may be reinforced and attacks using quantum computers may be blocked by incurring random noise in the decrypted data based on the functional encryption using the LWE problem and the lattice problem.