InfoSec Seminar: Blockmania: from Block DAGs to Consensus

Speaker: George Danezis

Date/Time: 08-Nov-2018, 16:00 UTC

Venue: Robert 3.09



Blockmania is a byzantine consensus protocol. Nodes emit blocks forming a directed acyclic graph (block DAG) that is subsequently interpreted by each node separately to ensure consensus with safety, liveness and finality. The resulting system has communication complexity O(N2) even in the worse case, and very low constant factors---as compared to O(N4) for PBFT; it is leaderless; and network operations do not depend on the composition of the quorum or node stake. This makes Blockmania very efficient (leading to over 400K transactions per second on a wide area network), and ideal for dynamic membership and flexible and non-interrupted proof-of-stake protocols. A X-Blockmania variant, has O(N) communication cost but also higher latency O(logN).


George heads the Information Security Research Group at University College London. He co-designed and prototyped RsCoin, an experimental scalable cryptocurrency for the Bank of England, and has a list of publications longer than a Leonard Cohen song. He did his doctorate at Cambridge under Ross Anderson, followed by a stint at Microsoft Research. George is also a Fellow at the Alan Turing Institute.

Add to Calendar

This page was last modified on 27 Mar 2014.