【录播】TED 区块链技术英文演讲 Part 2

3:49 Well, in 2008, the financial industry crashed and, perhaps propitiously, an anonymous person or persons named Satoshi Nakamoto created a paper where he developed a protocol for a digital cash that used an underlying cryptocurrency called Bitcoin. And this cryptocurrency enabled people to establish trust and do transactions without a third party. And this seemingly simple act set off a spark that ignited the world, that has everyone excited or terrified or otherwise interested in many places. Now, don't be confused about Bitcoin — Bitcoin is an asset; it goes up and down, and that should be of interest to you if you're a speculator. More broadly, it's a cryptocurrency. It's not a fiat currency controlled by a nation-state. And that's of greater interest. But the real pony here is the underlying technology. It's called blockchain. 4:56 So for the first time now in human history, people everywhere can trust each other and transact peer to peer. And trust is established, not by some big institution, but by collaboration, by cryptography and by some clever code. And because trust is native to the technology, I call this, "The Trust Protocol." 5:21 Now, you're probably wondering: How does this thing work? Fair enough. Assets — digital assets like money to music and everything in between — are not stored in a central place, but they're distributed across a global ledger, using the highest level of cryptography. And when a transaction is conducted, it's posted globally, across millions and millions of computers. And out there, around the world, is a group of people called "miners." These are not young people, they're Bitcoin miners. They have massive computing power at their fingertips — 10 to 100 times bigger than all of Google worldwide. These miners do a lot of work. And every 10 minutes, kind of like the heartbeat of a network, a block gets created that has all the transactions from the previous 10 minutes. Then the miners get to work, trying to solve some tough problems. 6:21 And they compete: the first miner to find out the truth and to validate the block, is rewarded in digital currency, in the case of the Bitcoin blockchain, with Bitcoin. And then — this is the key part — that block is linked to the previous block and the previous block to create a chain of blocks. And every one is time-stamped, kind of like with a digital waxed seal. So if I wanted to go and hack a block and, say, pay you and you with the same money, I'd have to hack that block, plus all the preceding blocks, the entire history of commerce on that blockchain, not just on one computer but across millions of computers, simultaneously, all using the highest levels of encryption, in the light of the most powerful computing resource in the world that's watching me. Tough to do. This is infinitely more secure than the computer systems that we have today. Blockchain. That's how it works.