A security apparatus identifies a first user associated with a first terminal apparatus within an area of a house to which entry is limited by a lock apparatus, and a second user associated with a second terminal apparatus approaching the house. The security apparatus determines a requirement for unlocking for the second user, based on a relationship of the second user with respect to the first user, and then determines whether the requirement for unlocking is satisfied. When the requirement for unlocking is satisfied, the security apparatus controls unlocking of the lock apparatus.