Enforcing Semantic Integrity on Untrusted Clients in Networked Virtual Environments

TL;DR

This paper introduces a cryptographic protocol to enforce semantic integrity in networked virtual environments, allowing servers to audit client computations efficiently without overloading the network or compromising real-time performance.

Contribution

A novel cryptographic-based semantic integrity protocol that enables efficient server-side auditing of client computations in NVEs, addressing security without high network costs.

Findings

Protocol enables on-demand auditing of client actions.

Achieves low network and CPU overhead.

Decouples auditing from real-time simulation constraints.

Abstract

During the last years, large-scale simulations of realistic physical environments which support the interaction of multiple participants over the Internet have become increasingly available and economically significant, most notably in the computer gaming industry. Such systems, commonly called networked virtual environments (NVEs), are usually based on a client-server architecture where for performance reasons and bandwidth restrictions, the simulation is partially deferred to the clients. This inevitable architectural choice renders the simulation vulnerable to attacks against the semantic integrity of the simulation: malicious clients may attempt to compromise the physical and logical laws governing the simulation, or to alter the causality of events a posteriori. In this paper, we initiate the systematic study of semantic integrity in NVEs from a security point of view. We argue that naive policies to enforce semantic integrity involve intolerable network load, and are therefore not practically feasible. We present a new semantic integrity protocol based on cryptographic primitives which enables the server system to audit the local computations of the clients on demand. Our approach facilitates low network and CPU load, incurs reasonable engineering overhead, and maximally decouples the auditing process from the soft real time constraints of the simulation.