Device Synchronisation: A Practical Limitation on Reader Assisted Jamming Methods for RFID Confidentiality

Abstract

Radio frequency identification (RFID) is a core component of the Internet-of-Things. In certain cases the communication between the tag and the reader needs to be confidential. Some passive RFID tags have very limited computational power and can therefore not implement standard cryptographic mechanisms. This has led to several proposals where data sent by the RFID tag is 'hidden' by noisy signals generated by the RFID reader. The RFID reader can remove the noise but third-party adversaries cannot, thereby ensuring a confidential backward-channel for tag data without the need for cryptography. Although this is a promising research direction there are also some practical limitations on the effectiveness of such schemes. This paper shows that at least one recent scheme is vulnerable to data recovery despite varying the reader's transmission power if there is a slight difference in the phase of the reader's blocking signal and the tag's data. We experimentally verify our attack and conclude that our eavesdropping and data recovery approach is effective and realistic. Finally we test three possible mitigation methods and show that two of the three approaches can provide protection against our attack while having little impact on the bit error rate of the reader in decoding the tag data.

Practical limitation of co-operative RFID jamming methods in environments without accurate signal synchronization

“…al. [21] also aims at mitigating the same problem of data leakage by signal desynchronization identified in our earlier work [13]. Their method adds high frequency noise, much higher frequency than that of the data, at transitions of the bit period.…”

“…Our previous research [13] has successfully simulated an eavesdropping attack on this jamming scheme. Simulation results show that we can reliably circumvent the primary Power Varying scheme under certain realistic conditions.…”

Tangible security: Survey of methods supporting secure ad-hoc connects of edge devices with physical context

“…It shows that the eavesdropper can not distinguish the bits with sequence 10 as the amplitudes of these two bits are the same. But according to another paper ( Hu et al, 2015 ), this method is vulnerable due to the unsynchronization of the reader signal and the tag signal. So this paper improved the vulnerable method by randomizing the interval and the increasing value.…”