The Truth Machine: The Blockchain and the Future of Everything. Paul Vigna

commit to connecting their next block to it if they are lucky enough to be the winner. If they’re unsatisfied, they would attach their new block to an earlier block whose contents they trust, leaving the suspicious one as an “orphan.” This decision-making forms the basis for Bitcoin’s consensus logic, which is based on a convention known as the “longest chain.” The idea is that if no miner has amassed more than 50 percent of total computing capacity, then mathematical probability will ensure that any attempt by a rogue minority to add a series of new ten-minute blocks to a previously rejected and orphaned one will soon fall behind the majority’s longer chain and will be abandoned. The caveat, of course, is that if bad actors do control more than 50 percent of the computing power they can produce the longest chain and so incorporate fraudulent transactions, which other miners will unwittingly treat as legitimate. Still, as we’ve explained, achieving that level of computing power is prohibitively expensive. It’s this combination of math and money that keeps Bitcoin secure.

      These cobbled-together concepts comprise Satoshi Nakamoto’s breakthrough: a decentralized, censorship-resistant record of the past. If we acknowledge that all accounting systems are merely estimates—that it’s impossible to arrive at a perfect representation of reality—then this one, a system that collectively captures the shared opinions of a community with no central authority, results in the most objective representation of the truth yet devised.

      In solving the double-spend problem, Bitcoin did something else important: it magically created the concept of a “digital asset.” Previously, anything digital was too easily replicated to be regarded as a distinct piece of property, which is why digital products such as music and movies are typically sold with licensing and access rights rather than ownership. By making it impossible to replicate something of value—in this case bitcoins—Bitcoin broke this conventional wisdom. It created digital scarcity