Centre for Research on Cryptography and Security, Faculty of Informatics, Masaryk University, Brno 60200, Czech Republic.
Sensors (Basel). 2019 Nov 19;19(22):5041. doi: 10.3390/s19225041.
Research in the area of security for Wireless Sensor Networks over the past two decades has yielded many interesting findings. We focus on the topic of (re-)securing link keys between sensor nodes through so-called secrecy amplification (SA) protocols. Crowdsourcing is at the very heart of these SA protocols. Not only do SA protocols work wonders even for low-level constrained nodes with no tamper resistance, they exhibit astonishing performance in networks under significant attacker control. Our work shows that even when 50% of all network links are compromised, SA protocols can re-secure over 90% of the link keys through an intriguingly simple crowdsourcing mechanism. These protocols allow us to re-take control without any broadly coordinated cooperation, without knowledge of the compromised links, with only very limited knowledge of each particular network node and independently of decisions made by other nodes. Our article first outlines the principles of and presents existing approaches to SA, introducing most of the important related concepts, then presents novel conclusive results for a realistic attacker model parametrised by attacker behaviour and capabilities. We undertook this work using two very different simulators, and we present here the results of analyses and detailed comparisons that have not previously been available. Finally, we report the first real, non-simulated network test results for the most attractive SA protocol, our implementations of which are available as open-source code for two platforms: Arduino and TinyOS. This work demonstrates the practical usability (and the attractive performance) of SA, serving as a ripe technology enabler for (among others) networks with many potentially compromised low-level devices.
在过去的二十年中，无线传感器网络安全领域的研究取得了许多有趣的成果。我们专注于通过所谓的保密增强（SA）协议重新保护传感器节点之间链路密钥的主题。众包是这些 SA 协议的核心。SA 协议不仅可以为没有防篡改能力的低级受限节点带来奇迹般的效果，而且在攻击者控制下的网络中表现出惊人的性能。我们的工作表明，即使所有网络链路中有 50%被破坏，SA 协议也可以通过一种非常简单的众包机制重新保护超过 90%的链路密钥。这些协议允许我们在没有广泛协调合作、不知道受攻击链路、只对每个特定网络节点有非常有限的了解以及不受其他节点决策影响的情况下重新获得控制权。
我们的文章首先概述了 SA 的原则和现有方法，介绍了大多数重要的相关概念，然后提出了针对现实攻击者模型的新颖结论性结果，该模型由攻击者行为和能力进行参数化。我们使用两个非常不同的模拟器进行了这项工作，并在这里展示了以前不可用的分析和详细比较的结果。最后，我们报告了第一个针对最具吸引力的 SA 协议的真实非模拟网络测试结果，我们的两个平台（Arduino 和 TinyOS）实现了该协议的开源代码。这项工作证明了 SA 的实际可用性（以及有吸引力的性能），为（包括）具有许多潜在受攻击的低级设备的网络提供了成熟的技术支持。
