Quorum systems are a key abstraction in distributed fault-tolerant computing for capturing trust assumptions. They can be found at the core of many algorithms for implementing reliable broadcasts, shared memory, consensus and other problems. This paper introduces asymmetric Byzantine quorum systems that model subjective trust. Every process is free to choose which combinations of other processes it trusts and which ones it considers faulty. Asymmetric quorum systems strictly generalize standard Byzantine quorum systems, which have only one global trust assumption for all processes. This work also presents protocols that implement abstractions of shared memory, broadcast primitives, and a consensus protocol among processes prone to Byzantine faults and asymmetric trust. The model and protocols pave the way for realizing more elaborate algorithms with asymmetric trust.
@article{arxiv.1906.09314,
title = {Asymmetric Distributed Trust},
author = {Orestis Alpos and Christian Cachin and Björn Tackmann and Luca Zanolini},
journal= {arXiv preprint arXiv:1906.09314},
year = {2024}
}
Comments
This work combines multiple preliminary publications on asymmetric trust and protocols with asymmetric trust, which appeared at OPODIS 2019, DISC 2021, and ESORICS-CBT 2021