Simon Willison’s Weblog

Imagine writing the investment memo for “20% of a picture of a dog” and being like “the most we should pay is probably about $2 million because the whole picture of the dog sold for $4 million three months ago and it can’t realistically have appreciated more than 150% since then; even if the whole picture of the dog is worth, aggressively, $10 million, this share would be worth $2 milllion.” What nonsense that is!

— Matt Levine # 10th September 2021, 7:27 am

Private blockchains are completely uninteresting. (By this, I mean systems that use the blockchain data structure but don’t have the above three elements.) In general, they have some external limitation on who can interact with the blockchain and its features. These are not anything new; they’re distributed append-only data structures with a list of individuals authorized to add to it. Consensus protocols have been studied in distributed systems for more than 60 years. Append-only data structures have been similarly well covered. They’re blockchains in name only, and -- as far as I can tell -- the only reason to operate one is to ride on the blockchain hype.

— Bruce Schneier # 12th February 2019, 7:14 pm

Easy explainer: a “blockchain” is a linked list with an append-only restriction, and appending is made incredibly expensive but super parallelizable, so when things work well a big group of people can work together and it’s too expensive for a small evil group to compete. [...] Does your problem benefit from storing information in an append-only list, and relying on a central authority to manage it is so bad that it’s worth paying the enormous append costs to have a bunch of Chinese servers manage it for you? Then *maybe* look at a blockchain.

— Tab Atkins # 9th August 2018, 1:27 am

A traditional centralized database only needs to be written to once. A blockchain needs to be written to thousands of times. A traditional centralized database needs to only checks the data once. A blockchain needs to check the data thousands of times. A traditional centralized database needs to transmit the data for storage only once. A blockchain needs to transmit the data thousands of times. The costs of maintaining a blockchain are orders of magnitude higher and the cost needs to be justified by utility. Most applications looking for some of the properties stated earlier like consistency and reliability can get such things for a whole lot cheaper utilizing integrity checks, receipts and backups.

— Jimmy Song # 24th May 2018, 2:44 pm

Watching companies gradually realize “blockchain is just super expensive consensus and only makes sense for untrusted counterparties” is a wild, expensive trip

— Kyle Kingsbury # 29th March 2018, 9:25 pm

Consider Bitcoin a grand middle finger. It’s a prank, almost a parody of the global financial system, that turned into a bubble. “You plutocrats of Davos may think you control the global money supply,” the pranksters seem to say. “But humans will make an economy out of anything. Even this!”

— Paul Ford # 10th March 2018, 11:34 am