Self-stabilizing Byzantine-tolerant Recycling

TL;DR

This paper introduces a self-stabilizing recycling mechanism for asynchronous consensus objects in Byzantine environments, enabling their safe reuse after completion despite arbitrary faults and process deviations.

Contribution

It presents the first self-stabilizing Byzantine-tolerant recycling method for asynchronous objects, combining synchrony assumptions with a new consensus algorithm.

Findings

Enables safe reuse of consensus objects after completion.

Provides a self-stabilizing Byzantine-tolerant consensus algorithm.

Builds on novel composition of existing techniques.

Abstract

Numerous distributed applications, such as cloud computing and distributed ledgers, necessitate the system to invoke asynchronous consensus objects an unbounded number of times, where the completion of one consensus instance is followed by the invocation of another. With only a constant number of objects available, object reuse becomes vital. We investigate the challenge of object recycling in the presence of Byzantine processes, which can deviate from the algorithm code in any manner. Our solution must also be self-stabilizing, as it is a powerful notion of fault tolerance. Self-stabilizing systems can recover automatically after the occurrence of arbitrary transient faults, in addition to tolerating communication and (Byzantine or crash) process failures, provided the algorithm code remains intact. We provide a recycling mechanism for asynchronous objects that enables their reuse once their task has ended, and all non-faulty processes have retrieved the decided values. This mechanism relies on synchrony assumptions and builds on a new self-stabilizing Byzantine-tolerant synchronous multivalued consensus algorithm, along with a novel composition of existing techniques.