According to an aspect of the inventive concept, there is provided a method of managing a smart-home environment by a server, including: receiving identification information and a password of a new smart device from a user terminal; generating a new group key based on the received identification information of the new smart device and identification information of an existing smart device; transmitting the new group key to the existing smart device; receiving identification information and a password from the new smart device; and comparing the identification information and the password received from the new smart device with the identification information and the password received from the user terminal, and transmitting the new group key to the new smart device according to a result of the comparison.