The promise of the blockchain: The trust machine
In summary, blockchain isto Bitcoin what peer to peer file sharing is to Napster.
http://www.economist.com/news/leaders/21677198-technology-behind-bitcoin-could-transform-how-economy-works-trust-machine
The blockchain is an even more potent technology. In essence it is a shared, trusted, public ledger that everyone can inspect, but which no single user controls. The participants in a blockchain system collectively keep the ledger up to date: it can be amended only according to strict rules and by general agreement. Bitcoin’s blockchain ledger prevents double-spending and keeps track of transactions continuously. It is what makes possible a currency without a central bank.
Blockchains are also the latest example of the unexpected fruits of cryptography. Mathematical scrambling is used to boil down an original piece of information into a code, known as a hash. Any attempt to tamper with any part of the blockchain is apparent immediately—because the new hash will not match the old ones. In this way a science that keeps information secret (vital for encrypting messages and online shopping and banking) is, paradoxically, also a tool for open dealing.
Bitcoin itself may never be more than a curiosity. However blockchains have a host of other uses because they meet the need for a trustworthy record, something vital for transactions of every sort. Dozens of startups now hope to capitalise on the blockchain technology, either by doing clever things with the bitcoin blockchain or by creating new blockchains of their own
One idea, for example, is to make cheap, tamper-proof public databases—land registries, say, (Honduras and Greece are interested); or registers of the ownership of luxury goods or works of art. Documents can be notarised by embedding information about them into a public blockchain—and you will no longer need a notary to vouch for them. Financial-services firms are contemplating using blockchains as a record of who owns what instead of having a series of internal ledgers. A trusted private ledger removes the need for reconciling each transaction with a counterparty, it is fast and it minimises errors. Santander reckons that it could save banks up to $20 billion a year by 2022. Twenty-five banks have just joined a blockchain startup, called R3 CEV, to develop common standards, and NASDAQ is about to start using the technology to record trading in securities of private companies.
These new blockchains need not work in exactly the way that bitcoin’s does. Many of them could tweak its model by, for example, finding alternatives to its energy-intensive “mining” process, which pays participants newly minted bitcoins in return for providing the computing power needed to maintain the ledger. A group of vetted participants within an industry might instead agree to join a private blockchain, say, that needs less security. Blockchains can also implement business rules, such as transactions that take place only if two or more parties endorse them, or if another transaction has been completed first. As with Napster and peer-to-peer technology, a clever idea is being modified and improved. In the process, it is fast throwing off its reputation for shadiness.
The spread of blockchains is bad for anyone in the “trust business”—the centralised institutions and bureaucracies, such as banks, clearing houses and government authorities that are deemed sufficiently trustworthy to handle transactions. Even as some banks and governments explore the use of this new technology, others will surely fight it. But given the decline in trust in governments and banks in recent years, a way to create more scrutiny and transparency could be no bad thing.
