The first decentralized cryptocurrency, bitcoin, was created in 2009 by pseudonymous developer Satoshi Nakamoto. It used SHA-256, a cryptographic hash function, as its proof-of-work scheme.[14][15] In April 2011, Namecoin was created as an attempt at forming a decentralized DNS, which would make internet censorship very difficult. Soon after, in October 2011, Litecoin was released. It was the first successful cryptocurrency to use scrypt as its hash function instead of SHA-256. Another notable cryptocurrency, Peercoin was the first to use a proof-of-work/proof-of-stake hybrid.[16]
Blockchains are secure by design and are an example of a distributed computing system with high Byzantine fault tolerance. Decentralized consensus has therefore been achieved with a blockchain.[29] Blockchains solve the double-spending problem without the need of a trusted authority or central server, assuming no 51% attack (that has worked against several cryptocurrencies).


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On 25 March 2014, the United States Internal Revenue Service (IRS) ruled that bitcoin will be treated as property for tax purposes. This means bitcoin will be subject to capital gains tax.[62] In a paper published by researchers from Oxford and Warwick, it was shown that bitcoin has some characteristics more like the precious metals market than traditional currencies, hence in agreement with the IRS decision even if based on different reasons.[63]


比特币与莱特币都采用了区块链技术,且都有51%攻击的问题。它们采用区块链技术,所有历史记录按照时间先后顺序,打包成一个个单独的区块,再把这些单独的区块链接在一起形成一个总账本 [5]  。这些区块内除了包含交易记录外,还包含新发行的莱特币和交易的手续费,这两笔钱支付给挖矿的矿工作为酬劳。无论谁挖到该区块,那么该区块内含有的新发行的莱特币和交易的手续费这两笔钱都归挖到者,以鼓励矿工积极参与结算。区块链技术容易产生51%攻击的问题:无论任何组织甚至个人,只要掌控某一种基于区块链原理的虚拟货币的全部运算能力的51%,这个人或组织就能够任意操纵该虚拟货币的所有交易。如果区块链只认运算能力最大者,谁的运算能力最大,谁就能抢到下一个区块,如果某个个人或组织掌控了全部运算能力的51%,那就意味着没人比他运算能力更强,故而他就可以随意操纵。所以,对于基于区块链原理的虚拟货币,参与挖矿的越多就越健壮,运算能力越分散就越健壮;挖坑者越少越脆弱,运算能力越集中就越脆弱,矿池越集中也就越脆弱 [1]  。


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Though karma rules still apply, moderation is less stringent on this thread than on the rest of the sub. Therefore, consider all information posted here with several liberal heaps of salt, and always cross check any information you may read on this thread with known sources. Any trade information posted in this open thread may be highly misleading, and could be an attempt to manipulate new readers by known "pump and dump (PnD) groups" for their own profit. BEWARE of such practices and exercise utmost caution before acting on any trade tip mentioned here. 


Cryptocurrencies are systems that allow for the secure payments of online transactions that are denominated in terms of a virtual "token," representing ledger entries internal to the system itself. "Crypto" refers to the fact that various encryption algorithms and cryptographic techniques, such as elliptical curve encryption, public-private key pairs, and hashing functions, are employed.
Coinbase has two core products: a Global Digital Asset Exchange (GDAX) for trading a variety of digital assets on its professional asset trading platform, and a user-facing retail broker of Bitcoin, Bitcoin Cash, Ether, Ethereum Classic, and Litecoin for fiat currency.[24] It also offers an API for developers and merchants to build applications and accept payments in both digital currencies. As of 2018, the company offered buy/sell trading functionality in 32 countries,[42] while the cryptocurrency wallet was available in 190 countries worldwide.[43] On March 26, 2018, Coinbase announced their intention to add support for ERC-20 tokens.[44]


In August 2019, Coinbase announced that it was targeted by a sophisticated hacking attack attempt in mid-June. This reported attack used spear-phishing and social engineering tactics (including sending fake e-mails from compromised email accounts and created a landing page at the University of Cambridge) and two Firefox browser zero-day vulnerabilities. One of the Firefox vulnerabilities could allow an attacker to escalate privileges from JavaScript on a browser page (CVE-2019–11707) and the second one could allow the attacker to escape the browser sandbox and execute code on the host computer (CVE-2019–11708). Coinbase's security team detected and blocked the attack, the network was not compromised, and no cryptocurrency was stolen.[39][40][41] 


If you want to trade in digital currencies, you are going to need a platform on which to trade them, and an intermediary to communicate with the network. Coinbase is a global digital asset exchange company (GDAX), providing a venue to buy and sell digital currencies, as well as send information about those transactions out to the blockchain network to verify those transactions. Coinbase serves as a wallet, too, where the digital currencies can be stored. The application operates exchanges of Bitcoin, Ethereum, Bitcoin Cash, and Litecoin, as well as other digital assets with fiat currencies in 32 countries, and Bitcoin transactions in many more countries. According to its website, Coinbase has served over 10 million customers and facilitated the exchange of more than $50 billion worth of digital currency.
To understand the revolutionary impact of cryptocurrencies you need to consider both properties. Bitcoin as a permissionless, irreversible, and pseudonymous means of payment is an attack on the control of banks and governments over the monetary transactions of their citizens. You can‘t hinder someone to use Bitcoin, you can‘t prohibit someone to accept a payment, you can‘t undo a transaction.

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^ "Bitcoin: The Cryptoanarchists' Answer to Cash". IEEE Spectrum. Archived from the original on 4 June 2012. Around the same time, Nick Szabo, a computer scientist who now blogs about law and the history of money, was one of the first to imagine a new digital currency from the ground up. Although many consider his scheme, which he calls "bit gold", to be a precursor to Bitcoin


Cryptocurrencies' blockchains are secure, but other aspects of a cryptocurrency ecosystem are not immune to the threat of hacking. In Bitcoin's 10-year history, several online exchanges have been the subject of hacking and theft, sometimes with millions of dollars worth of 'coins' stolen. Still, many observers look at cryptocurrencies as hope that a currency can exist that preserves value, facilitates exchange, is more transportable than hard metals, and is outside the influence of central banks and governments.


An initial coin offering (ICO) is a controversial means of raising funds for a new cryptocurrency venture. An ICO may be used by startups with the intention of avoiding regulation. However, securities regulators in many jurisdictions, including in the U.S., and Canada have indicated that if a coin or token is an "investment contract" (e.g., under the Howey test, i.e., an investment of money with a reasonable expectation of profit based significantly on the entrepreneurial or managerial efforts of others), it is a security and is subject to securities regulation. In an ICO campaign, a percentage of the cryptocurrency (usually in the form of "tokens") is sold to early backers of the project in exchange for legal tender or other cryptocurrencies, often bitcoin or ether.[47][48][49]


Essentially, if you are interested in trading in digital currencies but don't want to get bogged down in the underlying technology, products like Coinbase are a way to begin a foray into a new form of currency speculation and investing. You do, however, lose some of the advantages of trading in a cryptocurrency and through the blockchain. On Coinbase, you have no pseudo anonymity—your name is attached to your Coinbase account and so is your bank account, so transaction history is relatively easy to track down. And if you're not working on the blockchain, there's not much you can do to ensure that the verification of your transaction history or your account is taking place on the blockchain. You are, instead, placing trust in the intermediary, in this case, Coinbase.

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Two members of the Silk Road Task Force—a multi-agency federal task force that carried out the U.S. investigation of Silk Road—seized bitcoins for their own use in the course of the investigation.[68] DEA agent Carl Mark Force IV, who attempted to extort Silk Road founder Ross Ulbricht ("Dread Pirate Roberts"), pleaded guilty to money laundering, obstruction of justice, and extortion under color of official right, and was sentenced to 6.5 years in federal prison.[68] U.S. Secret Service agent Shaun Bridges pleaded guilty to crimes relating to his diversion of $800,000 worth of bitcoins to his personal account during the investigation, and also separately pleaded guilty to money laundering in connection with another cryptocurrency theft; he was sentenced to nearly eight years in federal prison.[69]
The novel hybrid consensus-based TrueChain tends to rely on POW consensus for random node selection, instead of using the slow chain mechanism to ensure security like Thunder.Although TrueChain has released dozens of Dapps, the number of its addresses (including active ones)and transactions is small. After the mainnet is launched, the project has run out of short-term bullish factors, which, plus the underdevelopment of its ecosystem, leads to a price slump within a short period of time. It will take some time for investors to regain confidence.
Cryptocurrencies are digital gold. Sound money that is secure from political influence. Money that promises to preserve and increase its value over time. Cryptocurrencies are also a fast and comfortable means of payment with a worldwide scope, and they are private and anonymous enough to serve as a means of payment for black markets and any other outlawed economic activity.


Darknet markets present challenges in regard to legality. Bitcoins and other forms of cryptocurrency used in dark markets are not clearly or legally classified in almost all parts of the world. In the U.S., bitcoins are labelled as "virtual assets". This type of ambiguous classification puts pressure on law enforcement agencies around the world to adapt to the shifting drug trade of dark markets.[75]
The one and only, the first and most famous cryptocurrency. Bitcoin serves as a digital gold standard in the whole cryptocurrency-industry, is used as a global means of payment and is the de-facto currency of cyber-crime like darknet markets or ransomware. After seven years in existence, Bitcoin‘s price has increased from zero to more than 650 Dollar, and its transaction volume reached more than 200.000 daily transactions.


Cryptocurrencies are experiencing a moment of unprecedented attention and speculation for several reasons. 1) The value of Bitcoin has been steadily climbing through 2017, with Ether seemingly poised to overtake the cryptocurrency giant any day; 2) Blockchain technology has purposes above and beyond cryptocurrency, and has been hailed by some as the backbone of the future financial system; 3) The increasing number of people who see cryptocurrency as a form of investment similar to gold. If cryptocurrencies stabilize in value, buying Bitcoin or Ether has the potential to be a worthy venture. 


Many people believe that cryptocurrencies are the hottest investment opportunity currently available. Indeed, there are many stories of people becoming millionaires through their Bitcoin investments. Bitcoin is the most recognizable digital currency to date, and just last year one BTC was valued at $800. In November 2017, the price of one Bitcoin exceeded $7,000.