TY - GEN
T1 - Brief Announcement
T2 - 39th Symposium on Principles of Distributed Computing, PODC 2020
AU - Cohen, Shir
AU - Keidar, Idit
AU - Spiegelman, Alexander
N1 - Publisher Copyright: © 2020 ACM.
PY - 2020/7/31
Y1 - 2020/7/31
N2 - King and Saia were the first to break the quadratic word complexity bound for Byzantine Agreement in synchronous systems against an adaptive adversary, and Algorand broke this bound with near-optimal resilience (first in the synchronous model and then with eventual-synchrony). Yet the question of asynchronous sub-quadratic Byzantine Agreement remained open. To the best of our knowledge, we are the first to answer this question in the affirmative. A key component of our solution is a shared coin algorithm based on a VRF. A second essential ingredient is VRF-based committee sampling, which we formalize and utilize in the asynchronous model for the first time. Our algorithms work against a delayed-adaptive adversary, which cannot perform after-the-fact removals but has full control of Byzantine processes and full information about communication in earlier rounds. Using committee sampling and our shared coin, we solve Byzantine Agreement with high probability, with a word complexity of Õ(n) and O(1) expected time, breaking the O(n2) bit barrier for asynchronous Byzantine Agreement.
AB - King and Saia were the first to break the quadratic word complexity bound for Byzantine Agreement in synchronous systems against an adaptive adversary, and Algorand broke this bound with near-optimal resilience (first in the synchronous model and then with eventual-synchrony). Yet the question of asynchronous sub-quadratic Byzantine Agreement remained open. To the best of our knowledge, we are the first to answer this question in the affirmative. A key component of our solution is a shared coin algorithm based on a VRF. A second essential ingredient is VRF-based committee sampling, which we formalize and utilize in the asynchronous model for the first time. Our algorithms work against a delayed-adaptive adversary, which cannot perform after-the-fact removals but has full control of Byzantine processes and full information about communication in earlier rounds. Using committee sampling and our shared coin, we solve Byzantine Agreement with high probability, with a word complexity of Õ(n) and O(1) expected time, breaking the O(n2) bit barrier for asynchronous Byzantine Agreement.
KW - VRF
KW - byzantine agreement
KW - shared coin
KW - sub-quadratic consensus protocol
UR - http://www.scopus.com/inward/record.url?scp=85090358788&partnerID=8YFLogxK
U2 - https://doi.org/10.1145/3382734.3405708
DO - https://doi.org/10.1145/3382734.3405708
M3 - منشور من مؤتمر
T3 - Proceedings of the Annual ACM Symposium on Principles of Distributed Computing
SP - 175
EP - 177
BT - PODC 2020 - Proceedings of the 39th Symposium on Principles of Distributed Computing
Y2 - 3 August 2020 through 7 August 2020
ER -