The invention discloses a
hybrid multi-mode multi-key fully
homomorphic encryption method based on a ring learning error problem. Comprising the following steps of public parameter initialization and
data set preparation, multi-participant
key generation and evaluation key joint generation, data
encryption,
ciphertext homomorphic operation,
noise evaluation and control, participant partial decryption and
server aggregation decryption. According to the method, the security
advantage under a ring structure, the efficient homomorphic multiplication capability of the BFV model and the floating-point number calculation mechanism of the CKKS model are combined, and the functions of multi-party key independent generation, public evaluation key joint construction, multi-
modal fusion,
ciphertext homomorphic multiplication, relinearization,
noise evaluation control and bootstrap refresh are supported; the problem that an existing
homomorphic encryption system has performance bottlenecks and potential safety hazards in the scenes of multi-participant key isolation,
ciphertext multiplication expandability,
noise control and dynamic participation is solved, and the method has good safety, expandability and calculation efficiency.