Authentication system, recording medium having recorded therein computer program controlling authentication system, and reader for use in authentication system

The recording medium of claim 9, wherein

• as the first read command, a preparation command and a read execution command are issued, the read execution command being a command to which ID information is returned as a response from the communicating contactless communication terminal,
• only when a response to the preparation command is received, the read execution command is received, and
• the computer program further causes the computer to execute:
• an avoiding step of, when a response to the preparation command that is issued in the additional issuance step is received and then reading of ID information fads as a response to the read execution command, that is issued in the additional issuance step, avoiding outputting the ID information read as the response to the second read command that has been issued immediately prior to the preparation command issued in the additional issuance step and type information indicating that the communicating contactless communication terminal is of the second type.

A reading device that reads ID information from a contactless communication terminal by repeatedly issuing a first read command and a second read command until receiving a response to either read command, the first read command being a command to which only a first type of contactless communication terminal responds, the second read command being a command to which both the first type of contactless communication terminal and a second type of contactless communication terminal respond, the reader comprising;

• a communication unit configured to communicate with a contactless communication terminal to issue read commands and receive a response to any of the read commands;
• and
• a reading unit configured to (i) read ID information as a response to the first read command via the communication unit, and then output the ID information and type information indicating that the contactless communication terminal communicating with the communication unit is of the first type, and (ii) read ID information as a response to the second read command via the communication unit, and then cause the communication unit to additionally issue the first read command, and when succeeding in reading ID information as a response to the additionally issued first read command via the communication unit, output the ID information and type information indicating that the communicating contactless communication terminal is of the first type.