The attraction then, as now, was the Columbia River, which we can glimpse a few blocks to our left. Bitcoin mining—the complex process in which computers solve a complicated math puzzle to win a stack of virtual currency—uses an inordinate amount of electricity, and thanks to five hydroelectric dams that straddle this stretch of the river, about three hours east of Seattle, miners could buy that power more cheaply here than anywhere else in the nation. Long before locals had even heard the words “cryptocurrency” or “blockchain,” Miehe and his peers realized that this semi-arid agricultural region known as the Mid-Columbia Basin was the best place to mine bitcoin in America—and maybe the world.
Skipping over the technical details, finding a block most closely resembles a type of network lottery. For each attempt to try and find a new block, which is basically a random guess for a lucky number, a miner has to spend a tiny amount of energy. Most of the attempts fail and a miner will have wasted that energy. Only once about every ten minutes will a miner somewhere succeed and thus add a new block to the blockchain.
The network requires minimal structure to share transactions. An ad hoc decentralized network of volunteers is sufficient. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will. Upon reconnection, a node downloads and verifies new blocks from other nodes to complete its local copy of the blockchain.
A wallet stores the information necessary to transact bitcoins. While wallets are often described as a place to hold or store bitcoins, due to the nature of the system, bitcoins are inseparable from the blockchain transaction ledger. A better way to describe a wallet is something that "stores the digital credentials for your bitcoin holdings" and allows one to access (and spend) them. Bitcoin uses public-key cryptography, in which two cryptographic keys, one public and one private, are generated. At its most basic, a wallet is a collection of these keys.
Armory’s fragmented backups is another useful feature. Instead of requiring multiple signatures for each transaction, fragmented backups require multiple signatures only for backups. A fragmented backup splits up your Armory backup into multiple pieces, which decreases the risk of physical theft of your wallet. Without a fragmented backup, discovery of your backup would allow for immediate theft. With fragmented backup, multiple backup locations would need to be compromised in order to obtain the full backup.
In March 2013 the blockchain temporarily split into two independent chains with different rules. The two blockchains operated simultaneously for six hours, each with its own version of the transaction history. Normal operation was restored when the majority of the network downgraded to version 0.7 of the bitcoin software. The Mt. Gox exchange briefly halted bitcoin deposits and the price dropped by 23% to $37 before recovering to previous level of approximately $48 in the following hours. The US Financial Crimes Enforcement Network (FinCEN) established regulatory guidelines for "decentralized virtual currencies" such as bitcoin, classifying American bitcoin miners who sell their generated bitcoins as Money Service Businesses (MSBs), that are subject to registration or other legal obligations. In April, exchanges BitInstant and Mt. Gox experienced processing delays due to insufficient capacity resulting in the bitcoin price dropping from $266 to $76 before returning to $160 within six hours. The bitcoin price rose to $259 on 10 April, but then crashed by 83% to $45 over the next three days. On 15 May 2013, US authorities seized accounts associated with Mt. Gox after discovering it had not registered as a money transmitter with FinCEN in the US. On 23 June 2013, the US Drug Enforcement Administration (DEA) listed 11.02 bitcoins as a seized asset in a United States Department of Justice seizure notice pursuant to 21 U.S.C. § 881. This marked the first time a government agency had seized bitcoin. The FBI seized about 26,000 bitcoins in October 2013 from the dark web website Silk Road during the arrest of Ross William Ulbricht. Bitcoin's price rose to $755 on 19 November and crashed by 50% to $378 the same day. On 30 November 2013 the price reached $1,163 before starting a long-term crash, declining by 87% to $152 in January 2015. On 5 December 2013, the People's Bank of China prohibited Chinese financial institutions from using bitcoins. After the announcement, the value of bitcoins dropped, and Baidu no longer accepted bitcoins for certain services. Buying real-world goods with any virtual currency had been illegal in China since at least 2009.