<>Central to the appeal and function of Bitcoin is the blockchain technology it uses to store an online ledger of all the transactions that have ever been conducted using bitcoins, providing a data structure for this ledger that is exposed to a limited threat from hackers and can be copied across all computers running Bitcoin software. Every new block generated must be verified by the ledgers of each user on the market, making it almost impossible to forge transaction histories. Many experts see this blockchain as having important uses in technologies such as online voting and crowdfunding, and major financial institutions such as JPMorgan Chase see potential in cryptocurrencies to lower transaction costs by making payment processing more efficient. However, because cryptocurrencies are virtual and do not have a central repository, a digital cryptocurrency balance can be wiped out by a computer crash if a backup copy of the holdings does not exist, or if somebody simply loses their private keys. At the same time, there is no central authority, government, or corporation that has access to your funds or your personal information. >
In May 2018, Bitcoin Gold (and two other cryptocurrencies) were hit by a successful 51% hashing attack by an unknown actor, in which exchanges lost estimated $18m. In June 2018, Korean exchange Coinrail was hacked, losing US$37 million worth of altcoin. Fear surrounding the hack was blamed for a $42 billion cryptocurrency market selloff. On 9 July 2018 the exchange Bancor had $23.5 million in cryptocurrency stolen.
<>While the country was once home to the world’s most active cryptocurrency exchanges, authorities banned the venues last year and have since moved to block access to platforms that offer exchange-like services. — Fortune, "China Is Said to be Cracking Down on a Cryptocurrency Loophole," 28 Feb. 2018 Bitcoin, however, has become the cryptocurrency standard operating much like U.S. dollar would operate in public currency markets, but in the crypto realm. — Michael C. Dealoia, cleveland.com, "Cleveland-area entrepreneurs are pouring resources into new-currency technolgoy: Tech Czar Talk," 25 Feb. 2018 Some companies, such as KODAK, have promoted cryptocurrency investments in hopes of reviving their flagging businesses. — Mike Rogoway, OregonLive.com, "SEC suspends trading in companies run by former Oregon football star over cryptocurrency 'concerns'," 16 Feb. 2018 >