KeySpace: Enhancing Public Key Infrastructure for Interplanetary Networks

TL;DR

This paper introduces KeySpace, a framework for evaluating PKI systems in interplanetary networks, demonstrating that existing protocols can be adapted for high-latency, interrupted environments and proposing improvements for efficiency and security.

Contribution

The paper develops a standardized testing framework for PKI in complex networks and demonstrates the effective adaptation of existing protocols like OCSP and CRLs for interplanetary communication.

Findings

OCSP and CRLs can be used effectively in interplanetary networks with high latency.

KeySpace enables fair comparison of PKI protocols across different network topologies.

Proposed techniques reduce overhead and improve security in PKI operations.

Abstract

As the use of satellites continues to grow, new networking paradigms are emerging to support the scale and long distance communication inherent to these networks. In particular, interplanetary communication relays connect distant network segments together, but result in a sparsely connected network with long-distance links that are frequently interrupted. In this new context, traditional Public Key Infrastructure (PKI) becomes difficult to implement, due to the impossibility of low-latency queries to a central authority. This paper addresses the challenge of implementing PKI in these complex networks, identifying the essential goals and requirements. Using these requirements, we develop the KeySpace framework, comprising a set of standardized experiments and metrics for comparing PKI systems across various network topologies, evaluating their performance and security. This enables the testing of different protocols and configurations in a standard, repeatable manner, so that improvements can be more fairly tested and clearly demonstrated. We use KeySpace to test two standard PKI protocols in use in terrestrial networks (OCSP and CRLs), demonstrating for the first time that both can be effectively utilized even in interplanetary networks with high latency and frequent interruptions, provided authority is properly distributed throughout the network. Finally, we propose and evaluate a number of novel techniques extending standard OCSP to improve the overhead of connection establishment, reduce link congestion, and limit the reach of an attacker with a compromised key. Using KeySpace we validate these claims, demonstrating their improved performance over the state of the art.