Optimal Self-Stabilizing Mobile Byzantine-Tolerant Regular Register with bounded timestamp

TL;DR

This paper introduces a novel self-stabilizing regular register resilient to mobile Byzantine agents and transient failures, utilizing bounded timestamps and optimized server requirements in a round-free synchronous setting.

Contribution

It presents the first implementation of a self-stabilizing register tolerant to mobile Byzantine agents and transient failures with bounded timestamps, under a more powerful adversary model.

Findings

Tolerates any number of transient failures and up to f mobile Byzantine agents.

Uses bounded timestamps from the 13 domain, ensuring practical timestamp management.

Optimal in the number of servers needed for the given adversary model.

Abstract

This paper proposes the first implementation of a self-stabilizing regular register emulated by $n$ servers that is tolerant to both mobile Byzantine agents, and \emph{transient failures} in a round-free synchronous model. Differently from existing Mobile Byzantine tolerant register implementations, this paper considers a more powerful adversary where (i) the message delay (i.e., $\delta$) and the period of mobile Byzantine agents movement (i.e., $\Delta$) are completely decoupled and (ii) servers are not aware of their state i.e., they do not know if they have been corrupted or not by a mobile Byzantine agent.The proposed protocol tolerates \emph{(i)} any number of transient failures, and \emph{(ii)} up to $f$ Mobile Byzantine agents. In addition, our implementation uses bounded timestamps from the $\mathcal{Z}\_{13}$ domain and it is optimal with respect to the number of servers needed to tolerate $f$ mobile Byzantine agents in the given model.