Position information providing system and position information providing method

A position information providing method in a position information providing system including at least one message transmitter and an authentication server synchronous in time with each other, the position information providing method comprising:

• generating, by each of the at least one message transmitter, an authentication code depending on time and a specific code uniquely allocated to each message transmitter;
• transmitting, by each of the at least one message transmitter, a message including position information and time information and the generated authentication code;
• certifying, by the authentication server, in response to an authentication request, from a receiver that has received a message from any of the at least one message transmitter, including information in the received message, authenticity of position information included in the authentication request, by determining validity of an authentication code included in the authentication request based on time information included in the authentication request and a specific code uniquely allocated to a message transmitter corresponding to the position information included in the authentication request;
• and
• storing the position information authenticity of which is certified.