No abstract

Wireless chip area networks (WCAN) signify a new development in wireless communications, where wireless interconnections among different cores within a chip (intrachip) or among different chips within a module (inter-chip) can be realized. In this paper, we analyze bit-error rate (BER) of an ultra-wideband (UWB) radio with binary phase-shift keying (BPSK) modulation over an inter-chip wireless radio channel. Specifically, a novel technique of dynamically shifting an integral window is proposed to reduce the effects of inter-symbol interference (ISI). BER expressions are analytically derived and verified by Monte Carlo simulations. Furthermore, by including both thermal and switching noise as the dominant noise sources, it is found that a BER less than 10 −6 is feasible for a link distance up to 252 mm at a data rate of up to 650 Mbps. Besides, the link margin analysis shows that a link margin of 28.22 dB could be obtained for the same distance and data rate. Index Terms-Wireless chip area networks, inter-chip, biterror rate, binary phase-shift keying.

Channel Reciprocity-based Key Generation (CRKG) exploits reciprocal channel randomness to establish shared secret keys between wireless terminals. This new security technique is expected to complement existing cryptographic techniques for secret key distribution of future wireless networks. In this paper, we present a new attack, reconfigurable intelligent surface (RIS) jamming, and show that an attacker can prevent legitimate users from agreeing on the same key by deploying a malicious RIS to break channel reciprocity. Specifically, we elaborate on three examples to implement the RIS jamming attack: Using active nonreciprocal circuits, performing time-varying controls, and reducing the signal-to-noise ratio. The attack effect is then studied by formulating the secret key rate with a relationship to the deployment of RIS. To resist such RIS jamming attacks, we propose a countermeasure that exploits wideband signals for multipath separation. The malicious RIS path is distinguished from all separated channel paths, and thus the countermeasure is referred to as contaminated path removal-based CRKG (CRP-CRKG). We present simulation results, showing that legitimate users under RIS jamming are still able to generate secret keys from the remaining paths. We also experimentally demonstrate the RIS jamming attack by using commodity Wi-Fi devices in conjunction with a fabricated RIS prototype. In our experiments, we were able to increase the average bit disagreement ratio (BDR) of raw secret keys by 20%. Further, we successfully demonstrate the proposed CRP-CRKG countermeasure to tackle RIS jamming in wideband systems as long as the source of randomness and the RIS propagation paths are separable.