# A Note on the Information-Theoretic-(in)Security of Fading Generated Secret Keys

## TL;DR

This paper investigates the security of wireless fading channel-generated secret keys against a powerful adversary, revealing potential vulnerabilities through a new colluding attack and analyzing information-theoretic security limits.

## Contribution

It introduces a sophisticated colluding attack model and quantifies the impact on secret key security under the laws of quantum mechanics.

## Key findings

- Identifies a new colluding attack on wireless secret keys.
- Quantifies the reduction in mutual information due to adversarial interceptors.
- Shows that adversaries can influence key rates from afar.

## Abstract

In this work we explore the security of secret keys generated via the electromagnetic reciprocity of the wireless fading channel. Identifying a new sophisticated colluding attack, we explore the information-theoretic-security for such keys in the presence of an all-powerful adversary constrained only by the laws of quantum mechanics. Specifically, we calculate the reduction in the conditional mutual information between transmitter and receiver that can occur when an adversary with unlimited computational and communication resources places directional antenna interceptors at chosen locations. Such locations, in principal, can be arbitrarily far from the intended receiver yet still influence the secret key rate.