Bitcoin and other cryptocurrencies have been identified as economic bubbles by at least eight Nobel Memorial Prize in Economic Sciences laureates, including Robert Shiller,[191] Joseph Stiglitz,[192] and Richard Thaler.[193][13] Noted Keyensian economist Paul Krugman wrote in his New York Times column criticizing bitcoin, calling it a bubble and a fraud;[194] and professor Nouriel Roubini of New York University called bitcoin the "mother of all bubbles."[195] Central bankers, including former Federal Reserve Chairman Alan Greenspan,[196] investors such as Warren Buffett,[197][198] and George Soros[199] have stated similar views, as have business executives such as Jamie Dimon and Jack Ma.[200]

Then two things happen. New transactions are added to the Bitcoin blockchain ledger, and the winning miner is rewarded with newly minted bitcoins. The miner also collects small fees that users voluntarily tack onto their transactions as a way of pushing them to the head of the line. It’s ultimately an exchange of electricity for coins, mediated by a whole lot of computing power. The probability of an individual miner winning the lottery depends entirely on the speed at which that miner can generate new hashes relative to the speed of all other miners combined. In this way, the lottery is more like a raffle, where the more tickets you buy in comparison to everyone else makes it more likely that your name will be pulled out of the hat.
Oct. 31, 2008: Someone using the name Satoshi Nakamoto makes an announcement on The Cryptography Mailing list at "I've been working on a new electronic cash system that's fully peer-to-peer, with no trusted third party. The paper is available at" This link leads to the now-famous white paper published on entitled "Bitcoin: A Peer-to-Peer Electronic Cash System." This paper would become the Magna Carta for how Bitcoin operates today.
And, inevitably, there was a growing tension with the utilities, which were finally grasping the scale of the miners’ ambitions. In 2014, the public utility district in Chelan County received requests from would-be miners for a total of 220 megawatts—a startling development in a county whose 70,000 residents were then using barely 200 megawatts. Similar patterns were emerging across the river in neighboring Douglas and Grant counties, where power is also cheap.
Because the target is such an unwieldy number with tons of digits, people generally use a simpler number to express the current target. This number is called the mining difficulty. The mining difficulty expresses how much harder the current block is to generate compared to the first block. So a difficulty of 70000 means to generate the current block you have to do 70000 times more work than Satoshi Nakamoto had to do generating the first block. To be fair, back then mining hardware and algorithms were a lot slower and less optimized.
Bitcoin's origin story sounds like something out of science fiction: It was launched in 2008 on the heels of a white paper published by the mysterious Satoshi Nakamoto, whose real identity – and country of origin – are unknown. Nakamoto conceived of Bitcoin as a currency that was 1) encrypted; 2) decentralized, i.e. it was ungoverned and did not belong to any nation; and 3) a digital "distributed ledger," such that everyone can verify online the legitimacy of transactions.
Keys come in pairs. The public key is used to encrypt the message whereas the private key decrypts the message. The only person with the private key is you. Everyone else is free to have your public key. As a result, everyone can send you encrypted messages without having to agree on a key beforehand. They simply use your public key and you untangle the gibberish by using your private key.
Desktop wallets are installed on a desktop computer and provide the user with complete control over the wallet. Desktop wallets enable the user to create a Bitcoin address for sending and receiving the Bitcoins. They also allow the user to store a private key. A few known desktop wallets are Bitcoin Core, MultiBit, Armory, Hive OS X, Electrum, etc.
What bitcoin miners actually do could be better described as competitive bookkeeping. Miners build and maintain a gigantic public ledger containing a record of every bitcoin transaction in history. Every time somebody wants to send bitcoins to somebody else, the transfer has to be validated by miners: They check the ledger to make sure the sender isn’t transferring money she doesn’t have. If the transfer checks out, miners add it to the ledger. Finally, to protect that ledger from getting hacked, miners seal it behind layers and layers of computational work—too much for a would-be fraudster to possibly complete.
In January 2009, the bitcoin network was created when Nakamoto mined the first block of the chain, known as the genesis block.[18][19] Embedded in the coinbase of this block was the following text: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks."[10] This note has been interpreted as both a timestamp and a comment on the instability caused by fractional-reserve banking.[20]:18