The Taub Faculty of Computer Science Events and Talks
Shir Cohen (Ph.D. Thesis Seminar)
Wednesday, 15.03.2023, 11:30
Advisor: Prof. Idit Keidar
For my PhD thesis seminar, I will be presenting two of my works related to the security and reliability of distributed services in the face of Byzantine attacks. In the first work “Not a COINcidence: Sub-Quadratic Asynchronous Byzantine Agreement WHP” (DISC’20), I present a solution for binary Byzantine Agreement (BA) in asynchronous systems, using a shared coin algorithm based on a VRF and VRF-based committee sampling. My algorithms work against a delayed-adaptive adversary with a word complexity of Õ(n) and O(1) expected time, breaking the O(n²) bit barrier for asynchronous Byzantine Agreement. This work is then used to solve the multivalued version of the BA problem.
In the second work “Tame the Wild with Byzantine Linearizability: Reliable Broadcast, Snapshots, and Asset Transfer” (DISC’21), I introduce the concept of Byzantine linearizability and study Byzantine-tolerant emulations of various objects from registers, including reliable broadcast, atomic snapshot, and asset transfer. This work proves that there is an f-resilient implementation of such objects from registers with n processes for f