Authentication system, authentication apparatus, authentication target apparatus, authentication method, method of being authenticated, program and information recording medium

An authentication apparatus which observes a radio wave from a radio star common to an authentication target apparatus at an observation time common to said authentication target apparatus, comprising:

• an observation unit which observes a radio wave from the common radio star at the common observation time;
• an information reception unit which receives information message sent from said authentication target apparatus;
• an estimation unit which estimates a position of said authentication target apparatus with respect to said authentication apparatus based on “‘information on a radio wave observed by said authentication target apparatus’ included in the received information message” and “information on the radio wave observed by said observation unif”;
• a retaining unit which retains position(s) of one or more authentication target apparatus(s) in advance;
• and
• a determination unit which settles authentication for the information message as a success, in a case where a position of said authentication target apparatus retained in said retaining unit in advance and the estimated position of said authentication target apparatus correspond to each other within a predetermined error range.

An authentication method of observing a radio wave from a radio star common to an authentication target apparatus at an observation time common to said authentication target apparatus, said method comprising:

• an observing step of observing a radio wave from the common radio star at the common observation time;
• an information receiving step of receiving an information message sent from said authentication target apparatus;
• an estimating step of estimating a position of said authentication target apparatus based on “‘information on a radio wave observed by said authentication target apparatus’ included in the received information message” and “information on the radio wave observed in said observing step”;
• and
• a determining step of settling authentication for the information message as a success, in a case where a position of said authentication target apparatus which is retained in advance and the estimated position of said authentication target apparatus correspond to each other within a predetermined error range.