Pyrofex is a U. S.-based company that has, among other projects, been working together with RChain Cooperative on the RChain project. Like Ethereum, RChain is supposed to use the Casper proof-of-stake consensus mechanism on the development of which RChain’s representatives have been collaborating with Ethereum’s researchers like Vitalik Buterin, with Vlad Zamfir active in both projects at the same time.
Recently, however, Pyrofex researchers have come to the conclusion that the Casper algorithm could not satisfy one of the key requirements for such protocols, namely liveness. In non-technical terms, a consensus protocol for a blockchain is live if it guarantees that under certain reasonable conditions transactions submitted by users will be included into approved blocks. According to a short paper published on the Pyrofex web-site, Casper does not satisfy this condition.
While we are not in position to evaluate the technical merits of the Casper critique, it should be noted that the Pyrofex team includes distributed-system researchers of the highest caliber and that, so far, to our best knowledge, there has been no response to the claim from the Casper research team.
Following up on their critique of Casper, the Pyrofex team proposed a consensus algorithm called Casanova that, according to them, is superior to Casper and has mathematically provable desirable properties. Technically-knowledgeable readers may consult the research paper outlining it here.
A more accessible explanation can be found in this article. The first core idea behind Casanova seems to be that in the real world, most of the transactions do not really require the sort of treatment that most blockchain protocols give them. Most people will not attempt to double-spend funds, hence, by default, incoming transactions can be easily processed. Secondly, if it is clear that two transactions cannot conflict, there is no need to track their order in time.
Hence, the consensus procedure is only necessary for a minority of transactions. Furthermore, in this design blocks may be approved even if they contain some problematic transactions. This, according to Pyrofex, ensures smooth processing of most transactions.
For consensus on conflicting transactions, the Casanova protocol uses a scoring approach that is based on a pre-blockchain consensus algorithm. Thus, the bold claim Pyrofex researchers make is that they managed to combine the practical advantages of public blockchain technology with the solid mathematics underlying classical, pre-Nakamoto consensus.
Although it is too early to tell whether Pyrofex’s approach to blockchain design will become a major competitor in the space, it will certainly be a project to watch in the coming years.