APPARATUS AND METHDO FOR GIVING THE COMPRESSED ENCRYPTION FUNCTIONALITY TO INTEGER-BASED HOMOMORPHIC ENCRYPTION SCHEMES

摘要

According to an embodiment of the present invention, a compressed encryption/decryption apparatus comprises: an interface for receiving a public key, a secret key, and a compression ratio; a memory for storing instructions which encrypt and decrypt a plaintext; and a processor for encrypting and decrypting the plaintext according to the instructions, wherein performing the instructions includes the steps of: changing the public and secret keys according to the compression ratio so as to generate an extension public key and an extension secret key; outputting the extension public key; receiving a compressed ciphertext; and decrypting the compressed ciphertext by truncating with respect to multiplication of the extension secret key and the compressed ciphertext.