Security Analysis of Quantization Schemes for Channel-based Key Extraction

Abstract

The use of reciprocal and random properties of wireless channels for the generation of secret keys is a highly attractive option for many applications that operate in a mobile environment. In recent years, several practice-oriented protocols have been proposed, but unfortunately without a sufficient and consistent security analysis and without a fair comparison between each other. This can be attributed to the fact that until now neither a common evaluation basis, nor a security metric in an on-line scenario (e.g., with changing channel properties) was proposed. We attempt to close this gap by presenting test vectors based on a large measurement campaign, an extensive comparative evaluation framework (including ten protocols as well as new on-line entropy estimators), and a rigorous experimental security analysis. Further, we answer for the first time a variety of security and performance related questions about the behavior of 10 channelbased key establishment schemes from the literature.

Authenticated key establishment for low-resource devices exploiting correlated random channels

“…[6] -A multitude of open research questions are formulated in recent works [3,4,5,6,8], all wondering about open, unaddressed issues in previous security analyses and adversarial models of physical-layer security schemes. We collect and address all these questions and present the first pairing protocol tailored for low-cost resourceconstrained wireless platforms and resistant against strong, active attackers.…”

“…8, key extraction starts with a synchronized block of channel measurements, which are quantized (quantize) applying the multilevel scheme by Jana et al [3]. The chosen quantization was recommended by Zenger et al [8] as a result of their security evaluation. In order to cope with disagreements due to imperfect channel-reciprocity, we utilize…”

A New Frontier for IoT Security Emerging From Three Decades of Key Generation Relying on Wireless Channels

“…To this end, a number of quantizer variants of the above two main approaches have been designed and tested. A comparison among different quantizers can be found in [119], [120].…”

A Practical Secret Key Generation Scheme Based on Wireless Channel Characteristics for 5G Networks

“…The quantization methods include binary quantization [10], adaptive secret bit generation [8], [15], differential quantization [16], non-uniform quantization [17] and multiple-bit quantization [18], [19], etc. The paper [20] summarizes some existing quantization methods. The preliminary key sequences obtained at Alice and Bob are often subject to discrepancies, particularly at very low SNR due to channel random noise and hardware limitations.…”