2018 IEEE International Parallel and Distributed Processing Symposium (IPDPS) (2018)
Vancouver, British Columbia, Canada
May 21, 2018 to May 25, 2018
A popular technique for tolerating malicious faults in open distributed systems is to establish small groups of participants, each of which has a non-faulty majority. These groups are used as building blocks to design attack-resistant algorithms. Despite over a decade of active research, current constructions require group sizes of O(log n), where n is the number of participants in the system. This group size is important since communication and state costs scale polynomially with this parameter. Given the stubbornness of this logarithmic barrier, a natural question is whether better bounds are possible. Here, we consider an attacker that controls a constant fraction of the total computational resources in the system. By leveraging proof-of-work (PoW), we demonstrate how to reduce the group size exponentially to O(log log n) while maintaining strong security guarantees. This reduction in group size yields a significant improvement in communication and state costs.
computational complexity, computer network security, fault tolerant computing, open systems, polynomials
M. O. Jaiyeola, K. Patron, J. Saia, M. Young and Q. M. Zhou, "Tiny Groups Tackle Byzantine Adversaries," 2018 IEEE International Parallel and Distributed Processing Symposium (IPDPS), Vancouver, British Columbia, Canada, 2018, pp. 1030-1039.