Path Hopping: An MTD Strategy for Long-Term Quantum-Safe Communication

Abstract

Moving target defense (MTD) strategies have been widely studied for securing computer systems. We consider using MTD strategies to provide long-term cryptographic security for message transmission against an eavesdropping adversary who has access to a quantum computer. In such a setting, today’s widely used cryptographic systems including Diffie-Hellman key agreement protocol and RSA cryptosystem will be insecure and alternative solutions are needed. We will use a physical assumption, existence of multiple communication paths between the sender and the receiver, as the basis of security, and propose a cryptographic system that uses this assumption and an MTD strategy to guarantee efficient long-term information theoretic security even when only a single path is not eavesdropped. Following the approach of Maleki et al., we model the system using a Markov chain, derive its transition probabilities, propose two security measures, and prove results that show how to calculate these measures using transition probabilities. We define two types of attackers that we call risk-taking and risk-averse and compute our proposed measures for the two types of adversaries for a concrete MTD strategy. We will use numerical analysis to study tradeoffs between system parameters, discuss our results, and propose directions for future research.

On Randomization in MTD Systems

“…To further improve security and efficiency of the system against a dynamic adversary that changes the set of their eavesdropped paths over time, a Moving Target Defence (MTD) approach to SMT systems was proposed [17].…”

“…The system is proved to provide post-quantum security without relying on a secret key or intractability assumption. The system was published in [17] and used an evaluation framework for the MTD strategy that was proposed in [1,9]. We motivate the need for implementation and experiments to (i) understand the cost of employing the system in practice to refine the model and make the results closer to a real-life implementation, and (ii) to validate the assumptions and evaluate performance of the system in practice.…”

Polymorphic Path Transferring for Secure Flow Delivery

“…By now, the researchers have put more emphasis on changing static parameters of the data flow on the fly [16,17,18,19,20]. The IP address [21], the port [22], and the routing path of a flow [11,19,20,23,24,25] are the main objects of dynamic configuration.…”

More than a Fair Share: Network Data Remanence Attacks against Secret Sharing-based Schemes

“…Dolev and Tzur-David [13] propose a secret sharing scheme over multiple network paths to mitigate the problem of stolen or short keys (i.e., implementation vulnerabilities). Ahmadi et al [1] and later Safavi-Naini et al [30] considered models where shares of the message are sent over multiple paths that are changing (switching) in each time interval, and proved that the system provides information theoretic security and so stays secure against a quantum computer. Applications on real networks for such schemes, which combine secret sharing with multi-path switching, have also started to be proposed, including [10], which applies secret sharing to provide security for controller and switch communication in the face of an adversary with quantum computing capabilities in Software-Defined Networks (SDNs).…”

“…In this work, our goal is to examine the real-world security of schemes that combine secret sharing with multipath switching. We consider the scheme in [30] (referred to in the rest of this paper as Multi-path Switching with Secret Sharing or, for short, MSSS) because it was shown to have perfect information theoretic security. The security of MSSS relies on the assumptions that paths are atomic and packets travel on such paths with the same delay.…”