I wish this article had a bit more systematic approach. I've been recently looking into consensus protocols, and there are at least two dimensions to consider:

I wish this article had a bit more systematic approach. I've been recently looking into consensus protocols, and there are at least two dimensions to consider: permissioned (participants are known in advance) vs permissionless (anyone can join), and partially synchronous (some guarantees about message delivery time) vs asynchronous (only the delivery is guaranteed, the time can be at any point in the future). There are also some recent developments loosely based on Ben-Or protocol (HoneyBadgerBFT, HashGraph) that look a lot more promising than blockchain-based consensus.