The invention relates to an RFID tag, which comprises a receiving means, a first and a second verification means, and a transmitting means. The receiving means is designed to receive a challenge message sent by an RFID reading device. Said challenge message comprises a challenge data set, which has a digital certificate issued for the RFID reading device by a certification authority and signed by means of a private key of the certification authority and which has a request message, and a digital signature at least of the request message, which digital signature is generated by means of a private key of the RFID reading device. The first verification means is designed to verify the digital certificate by means of a public key of the certification authority. The second verification means is designed to verify the digital signature by means of a public key of the RFID reading device. The transmitting means transmits a response message to the REID reading device if the certificate and the digital signature are verified. By verifying the challenge message, the RFID tag can ensure that the RFID tag transmits a response message only to such a requesting REID reading device that is actually authorized to communicate with said RFID tag.