A computer-implemented method includes: encrypting, by a first data party, identification data to generate a first identification data ciphertext, in which the first data party holds an identification dataset including the identification data; sending a first ciphertext set to a second data party, in which the first ciphertext set includes the first identification data ciphertext; receiving a second ciphertext set from the second data party; decrypting the second identification data ciphertext to generate a third identification data ciphertext, in which a third ciphertext set includes the third identification data ciphertext; receiving a fourth ciphertext set from the second data party, obtaining the third identification data ciphertext common to the third ciphertext set and the fourth ciphertext set; calculating a homomorphic addition result of the business data ciphertext corresponding to the third identification data ciphertext; and sending the homomorphic addition result to the second data party.