A team of researchers at Pyrofex Corporation recently introduced Casanova, a leaderless optimistic consensus algorithm suited for use in a blockchain. Rather than producing a chain, Casanova produces blocks in a directed acyclic graph (DAG), which is essentially a directed graph with no cycles. Casanova pipelines voting rounds and block production to improve scalability and has a unique ‘line item veto’ for conflicting transactions such as double spends.
Most existing blockchain technologies waste considerable time and resources getting the entire network to agree on the global ordering of each single transaction. While this might appear reasonable, the researchers feel that a good blockchain approach should be able to process transactions in any order.