According to an embodiment of the present disclosure, a ring-learning with rounding (LWR)-based quantum-resistant signature method includes: a key generation step of receiving a security parameter, and outputting a signature key and a verification key, via an operation on a ring defined by a cyclotomic equation including three terms; a signature value output step of outputting a signature value based on the output signature key; and a signature verification step of calculating an operation value based on the output verification key and signature value, and verifying a signature based on a result of comparing the output signature value with the calculated operation value.