Non-collaborative Attackers and How and Where to Defend Flawed Security Protocols (Extended Version)

TL;DR

This paper proposes a network topology-based defense mechanism using benign guardians to detect and interrupt ongoing attacks on flawed security protocols, allowing continued use until fixes are deployed.

Contribution

It introduces a novel approach employing strategic network guardians to mitigate attacks on flawed protocols without complete protocol dismissal.

Findings

Guardians can effectively detect ongoing attacks in certain network topologies.

Strategic placement of guardians enhances attack mitigation capabilities.

The approach allows continued protocol use until official fixes are available.

Abstract

Security protocols are often found to be flawed after their deployment. We present an approach that aims at the neutralization or mitigation of the attacks to flawed protocols: it avoids the complete dismissal of the interested protocol and allows honest agents to continue to use it until a corrected version is released. Our approach is based on the knowledge of the network topology, which we model as a graph, and on the consequent possibility of creating an interference to an ongoing attack of a Dolev-Yao attacker, by means of non-collaboration actuated by ad-hoc benign attackers that play the role of network guardians. Such guardians, positioned in strategical points of the network, have the task of monitoring the messages in transit and discovering at runtime, through particular types of inference, whether an attack is ongoing, interrupting the run of the protocol in the positive case. We study not only how but also where we can attempt to defend flawed security protocols: we investigate the different network topologies that make security protocol defense feasible and illustrate our approach by means of concrete examples.