>>10367174Consensus among antagonists using the internet.
E.g. when you currently want to know the weather in Sydney, you have to rely on some provider. Someone or several people who set up a server (accessible through
weather.com, say) that you can quiery. If you got a protocol where (possibly malicious) people interact to come up with one particular value, then you can get more trustable information. Protocols like BFT algorithms are from the 60's or whatnot and can stomach up to 33% malicious nodes.
https://en.wikipedia.org/wiki/Byzantine_faultBut the BFT protocol has an immense network communication overhead and it's also suseptible to a sybil attack (one entity predents to be several people)
https://en.wikipedia.org/wiki/Sybil_attackIn 2008 someone ("Nakatmoto") cam up with the idea of using proof of work (an idea from the 90's) together with a Merkle tree (a 70's data structure, of which the "block chain" is a special case) for consensus. It tolerates up to 50% and is immune to a certain kind of sybil attack (because it's based on computer power, not votes). It's a shit protocol in terms of energy consumption, but it kickstarted a broader consensus mechanism research field.
