A General Security Approach for Soft-information Decoding against Smart Bursty Jammers

TL;DR

This paper presents a general method to improve soft-information decoding in wireless communications under smart bursty jamming by updating reliability information, significantly reducing error rates and preventing DoS.

Contribution

It introduces a pre-decoding step that leverages temporal dependencies of bursty jammers to enhance decoding without modifying existing algorithms.

Findings

Significant reduction in block-error rate (BLER) with the proposed method.

Effective inference of jamming presence in received frames.

Prevents complete denial of service (DoS) in simulations.

Abstract

Malicious attacks such as jamming can cause significant disruption or complete denial of service (DoS) to wireless communication protocols. Moreover, jamming devices are getting smarter, making them difficult to detect. Forward error correction, which adds redundancy to data, is commonly deployed to protect communications against the deleterious effects of channel noise. Soft-information error correction decoders obtain reliability information from the receiver to inform their decoding, but in the presence of a jammer such information is misleading and results in degraded error correction performance. As decoders assume noise occurs independently to each bit, a bursty jammer will lead to greater degradation in performance than a non-bursty one. Here we establish, however, that such temporal dependencies can aid inferences on which bits have been subjected to jamming, thus enabling counter-measures. In particular, we introduce a pre-decoding processing step that updates log-likelihood ratio (LLR) reliability information to reflect inferences in the presence of a jammer, enabling improved decoding performance for any soft detection decoder. The proposed method requires no alteration to the decoding algorithm. Simulation results show that the method correctly infers a significant proportion of jamming in any received frame. Results with one particular decoding algorithm, the recently introduced ORBGRAND, show that the proposed method reduces the block-error rate (BLER) by an order of magnitude for a selection of codes, and prevents complete DoS at the receiver.