If fewer people begin to accept Bitcoin as a currency, these digital units may lose value and could become worthless. There is already plenty of competition, and though Bitcoin has a huge lead over the other 100-odd digital currencies that have sprung up, thanks to its brand recognition and venture capital money, a technological break-through in the form of a better virtual coin is always a threat.
Bitcoin is a digital currency created in 2009. It follows the ideas set out in a white paper by the mysterious Satoshi Nakamoto, whose true identity has yet to be verified. Bitcoin offers the promise of lower transaction fees than traditional online payment mechanisms and is operated by a decentralized authority, unlike government-issued currencies.
Numerous people have been suggested as possible Satoshi Nakamotos by major media outlets. On Oct. 10, 2011, The New Yorker published an article speculating that Nakamoto might be Irish cryptography student Michael Clear, or economic sociologist Vili Lehdonvirta. A day later, Fast Company suggested that Nakamoto could be a group of three people – Neal King, Vladimir Oksman and Charles Bry – who together appear on a patent related to secure communications that was filed two months before bitcoin.org was registered. A Vice article published in May 2013 added more suspects to the list, including Gavin Andresen, the Bitcoin project’s lead developer; Jed McCaleb, co-founder of now-defunct Bitcoin exchange Mt. Gox; and famed Japanese mathematician Shinichi Mochizuki.
In March the bitcoin transaction log called the blockchain temporarily split into two independent chains with differing rules on how transactions were accepted. For six hours two bitcoin networks operated at the same time, each with its own version of the transaction history. The core developers called for a temporary halt to transactions, sparking a sharp sell-off. 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 exchange rate briefly dipped by 23% to $37 as the event occurred before recovering to previous level of approximately $48 in the following hours. In the US, the 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 (or MSBs), that may be subject to registration and other legal obligations.
To heighten financial privacy, a new bitcoin address can be generated for each transaction. For example, hierarchical deterministic wallets generate pseudorandom "rolling addresses" for every transaction from a single seed, while only requiring a single passphrase to be remembered to recover all corresponding private keys. Researchers at Stanford and Concordia universities have also shown that bitcoin exchanges and other entities can prove assets, liabilities, and solvency without revealing their addresses using zero-knowledge proofs. "Bulletproofs," a version of Confidential Transactions proposed by Greg Maxwell, have been tested by Professor Dan Boneh of Stanford. Other solutions such Merkelized Abstract Syntax Trees (MAST), pay-to-script-hash (P2SH) with MERKLE-BRANCH-VERIFY, and "Tail Call Execution Semantics", have also been proposed to support private smart contracts.
Venture capitalists, such as Peter Thiel's Founders Fund, which invested US$3 million in BitPay, do not purchase bitcoins themselves, but instead fund bitcoin infrastructure that provides payment systems to merchants, exchanges, wallet services, etc. In 2012, an incubator for bitcoin-focused start-ups was founded by Adam Draper, with financing help from his father, venture capitalist Tim Draper, one of the largest bitcoin holders after winning an auction of 30,000 bitcoins, at the time called "mystery buyer". The company's goal is to fund 100 bitcoin businesses within 2–3 years with $10,000 to $20,000 for a 6% stake. Investors also invest in bitcoin mining. According to a 2015 study by Paolo Tasca, bitcoin startups raised almost $1 billion in three years (Q1 2012 – Q1 2015).
Illiquidity. This is mostly moot due to Bitcoin’s $47 market cap but it still makes users sweat. It’s highly unlikely that Bitcoin’s price would plummet and you’d be unable to take action, but it’s still unsettling. As more investors invest, however, illiquidity becomes a negligible risk, as there will likely always be a buyer for Bitcoins waiting.
An official investigation into bitcoin traders was reported in May 2018. The U.S. Justice Department launched an investigation into possible price manipulation, including the techniques of spoofing and wash trades. Traders in the U.S., the U.K, South Korea, and possibly other countries are being investigated. Brett Redfearn, head of the U.S. Securities and Exchange Commission's Division of Trading and Markets, had identified several manipulation techniques of concern in March 2018.
Investigations into the real identity of Satoshi Nakamoto were attempted by The New Yorker and Fast Company. The New Yorker's investigation brought up at least two possible candidates: Michael Clear and Vili Lehdonvirta. Fast Company's investigation brought up circumstantial evidence linking an encryption patent application filed by Neal King, Vladimir Oksman and Charles Bry on 15 August 2008, and the bitcoin.org domain name which was registered 72 hours later. The patent application (#20100042841) contained networking and encryption technologies similar to bitcoin's, and textual analysis revealed that the phrase "... computationally impractical to reverse" appeared in both the patent application and bitcoin's whitepaper. All three inventors explicitly denied being Satoshi Nakamoto.