Gate opening method and door unlocking method using portable terminal network address

A door unlocking method, comprising:

• a step of transmitting a door unlock signal for making a request for unlocking of a door of an object, to the object by using an authenticated network address unique to a mobile device;
• a step of determining whether or not to allow the unlocking of the door based on a management table and the authenticated network address of the mobile device in response to reception of the door unlock signal;
• and
• a step of unlocking the door in response to a determination that the unlocking of the door is allowed,
• wherein the management table includes a plurality of pieces of network address information indicating a plurality of authenticated network addresses unique to a plurality of mobile devices each of which is associated with one of a plurality of users;
• and
• wherein authentication of the authenticated network address is determined based on a public key corresponding to a private key of the mobile terminal.