A multi-party variance multiplication device includes: an initial setting device which generates a first public key by using an inputted system parameter; a commitment generation device which generates a commitment of a first input value based on the system parameter and a random number; an encryption device which generates an encrypted text of the first input value based on the system parameter, the random number, and the first public key; an authentication device which generates a certificate that authenticates a range of the first input value based on the system parameter, the random number, the first public key, and the second public key already public; a decryption device which generates a decrypted text by decrypting a noisy encrypted text based on the system parameter, the first public key, and a private key; and a noise removal device which generates a product variance by removing a noise from the decrypted text.