On the security of a new ultra-lightweight authentication protocol in IoT environment for RFID tags

Recently, Tewari and Gupta proposed a ultra-lightweight mutual authentication protocol in IoT environments for RFID tags. Their protocol aims to provide secure communication with least cost in both storage and computation. Unfortunately, in this paper, we exploit the vulnerability of this protocol. In this attack, an attacker can obtain the key shared between a back-end database server and a tag. We also explore the possibility in patching the system with some modifications.