PURPOSE : A real estate brokerage method is provided to connect a seller with a buyer using an open ticket number, thereby protecting the personal information of the seller or the buyer.CONSTITUTION : Registration of sales information is requested(S410). A ticket number request web page is transmitted(S440). A text message including the first authentication number is transmitted to the first communication terminal of the seller. The second authentication number is transmitted. If the second authentication number is the same as the first authentication number, a ticket number is generated. A request for a call is made to the first communication terminal(S480).COPYRIGHT KIPO 2010