Improvement and partial simulation of King & Saia’s expected-polynomial-time Byzantine agreement algorithm

• Main Author: Kimmett, Ben
• Other Authors: Coady, Yvonne
• Format: Others
• Language: English; en
• Published: 2020
• Subjects: byzantine agreement; interactive consistency; Bracha; x-sync; shared coin flip; decision; adversary; asynchronous; reliable broadcast; validation; blackboard; Monte Carlo simulation; polynomial time; King-Saia; King; Saia; resilience; improved resilience; Global-Coin
• Online Access: http://hdl.handle.net/1828/11836

We present a partial implementation of King and Saia 2016’s expected polyno- mial time byzantine agreement algorithm, which which greatly speeds up Bracha’s Byzantine agreement algorithm by introducing a shared coin flip subroutine and a method for detecting adversarially controlled nodes. In addition to implementing the King-Saia algorithm, we detail a new version of the “blackboard” abstraction used to implement the shared coin flip, which improves the subroutine’s resilience from t < n/4 to t < n/3 and leads to an improvement of the resilience of the King-Saia Byzantine agreement algorithm overall. We test the King-Saia algorithm, and detail a series of adversarial attacks against it; we also create a Monte Carlo simulation to further test one particular attack’s level of success at biasing the shared coin flip === Graduate