On blockchains and why secure ledgers don't require proof-of-work
Ugh. He completely misunderstands what PoW (or PoS) are for. The <i>entire point</i> of PoW is deciding between two valid &amp; correct blockchain states.<p>Alice owns a bitcoin. Alice validly signs a transaction transferring that bitcoin to Bob. Alice also validly signs a transaction transferring that same bitcoin to Charles.<p>WHICH IS CORRECT? Neither is a forgery. Both signatures are valid. If Dave downloads the blockchain, or receives both transactions, he can&#x27;t just look at them and determine one of them is fake. Neither is fake. He needs a way of arbitrating who actually has the bitcoin now - Bob or Charles.<p>PoW is that arbitration process. Dave looks at the competing blockchains (one with Bob having received it, and one with Charles having received it) and can trust that everyone in the world will respect the chain with greater PoW behind it.<p>Paul&#x27;s system has no way of addressing this other than &quot;trust the central authority to process transactions in the order they receive them&quot;. Thanks, pal, that&#x27;s called e-cash, and was invented by David Chaum in 1983.