Robust Restaking Networks

TL;DR

This paper analyzes the security risks in restaking networks, providing bounds on stake loss and attack cascade length, and offers measures and conditions to enhance robustness against validator reuse risks.

Contribution

It introduces a theoretical framework for assessing and guaranteeing the security of restaking networks, including bounds on stake loss and attack cascades, with computable conditions for robustness.

Findings

Stake loss is bounded by attack cost-profit margins.

Maximum attack cascade length is bounded.

Proposes polynomial-time conditions for robustness.

Abstract

We study the risks of validator reuse across multiple services in a restaking protocol. We characterize the robust security of a restaking network as a function of the buffer between the costs and profits from attacks. For example, our results imply that if attack costs always exceed attack profits by 10\%, then a sudden loss of .1\% of the overall stake (e.g., due to a software error) cannot result in the ultimate loss of more than 1.1\% of the overall stake. We also provide local analogs of these overcollateralization conditions and robust security guarantees that apply specifically for a target service or coalition of services. All of our bounds on worst-case stake loss are the best possible. Finally, we bound the maximum-possible length of a cascade of attacks. Our results suggest measures of robustness that could be exposed to the participants in a restaking protocol. We also suggest polynomial-time computable sufficient conditions that can proxy for these measures.