A method to update reference verification information used for electrocardiogram (ECG) signal verification includes: identifying a first ECG signal measured from a user； verifying the first ECG signal by comparing a second ECG signal included in a reference ECG signal set with the first ECG signal； in response to the first ECG signal being successfully verified, setting the successfully verified first ECG signal to be a third ECG signal, and adding the third ECG signal to a verified ECG signal set； and updating the reference ECG signal set by setting the third ECG signal added to the verified ECG signal set to be an additional second ECG signal, based on the reference ECG signal set and the verified ECG signal set.
