Secure and fast missing RFID tags identification with lightweight MAC and rateless coding

The realtime identification of missing items, e.g., valuables or confidential documents in shops and warehouses, is one of the most important system. Although many RFID-based schemes that quickly identify missing tag-attached items are proposed, most of the schemes overlooks the possibility of the internal crime. If a person controls an untrusted reader, he/she can freely forge responses from tags and steal items without being detected. In this paper, we propose a secure and fast missing tags identification against both the internal and external attackers. Our scheme first identifies tags stolen by an external attacker with a channel estimation based scheme. Then, our scheme lets tags send cryptographically generated responses, which are socalled MAC (Message Authentication Code), and verifies them to identify stolen tags by an internal attacker. In order to shorten the time to collect responses, our scheme lets multiple tags transmit responses simultaneously and decodes them by leveraging the estimated channels. By the security analysis and the computer simulation, we show the effectiveness of our scheme.