Optimal Key-Tree for RFID Authentication Protocols with Storage Constraints

摘要

Tree-based RFID authentication protocols provide an efficient solution for lowering authentication delay, but level of privacy provided by tree-based systems decreases considerably if some members are compromised and secret keys are probed. In the RFID system, Tags are severely limited in terms of computational power and storage. A large amount of research focused on optimizing the key-tree has been launched, yet none of them consider the Tags' storage constraints. In this paper, we introduce a new privacy metric expression for measuring the resistance of the system to a single compromised member; we furtherly extend the research work of Buttyan et al. and Beye et al. by proposing two optimization problems respecting storage constraints. In addition, we show how to construct the optimal key-tree in order to maximize the system's resistance to single member compromise under the constraints on the Tags' number, the maximum authentication delay and the number of the keys stored in the Tag.