澄清误解

让我们在此澄清一些对比特币的误解。

比特币和扣币一样，不是什么新鲜货

其它的虚拟货币全部是集中控制的，这意味着：

• 控制者可以想发多少发多少
• 通过攻击中心节点就能毁灭它
• 控制者可以任意对使用者提出限制

去中心化的比特币解决了上述问题。

金子搞不定的问题比特币也没辙

比特币与黄金不同的地方：

• 方便运输和存储
• 方便检查认证

和法定货币不同，比特币：

• 有可预测的总量
• 无中心管理机构

和法定电子货币不同，比特币:

• 具有潜在的匿名性
• 资产无法被冻结

比特币以CPU的处理速度为凭证

比特币以CPU的处理能力为凭证的说法是不正确的。一种货币以何为凭表示that it is pegged to something else via a central party at a certain exchange rate. You cannot exchange bitcoins for the computing power that was used to create them. Bitcoin is in this sense not backed by anything. It is a commodity in its own right. Similar to gold - is gold backed by anything? No! It's just gold. Same thing with bitcoin.

The Bitcoin currency is created via processing power, and the integrity of the block chain is protected by the existence of a large network of computing nodes from certain possible attacks. And that is all.

Bitcoins are worthless because they aren't backed by anything

Gold isn't backed by anything either. Bitcoins have properties inherent to its design that are subjectively valued by individuals. This valuation is demonstrated when individuals freely exchange for or with Bitcoins. Please refer to the Subjective Theory of Value. See also myth Bitcoin is backed by CPU cycles.

Bitcoins value is based on how much electricity and computing power it takes to mine them

This statement is an attempt to apply to bitcoin the labor theory of value, which is generally accepted as false. Just because something takes X resources to create does not mean that the resulting product will be worth X. It can be worth more, or less, depending on the utility thereof to its users.

In fact the causality is the reverse of that (this applies to the labor theory of value in general). The cost to mine bitcoins is based on how much they are worth. If bitcoins go up in value, more people will mine (because mining is profitable), thus [difficulty] will go up, thus the cost of mining will go up. The inverse happens if bitcoins go down in value. These effects balance out to cause mining to always cost the amount of bitcoins it produces.

比特币没有固有价值（和别的不同）

It is true that bitcoins have no intrinsic value, in the numismatic sense, in other words, value in any realm outside of being used as a medium of exchange.

However, while some tangible commodities do have intrinsic value, that value is generally much less than its trading price. Consider for example that gold, if it were not used as an inflation-proof store of value, but rather only for its industrial uses, would certainly not be worth what it is today, since the industrial requirements for gold are far smaller than the available supply thereof.

While historically intrinsic value, as well as other attributes like divisibility, fungibility, scarcity, durability, helped establish certain commodities as mediums of exchange, it is certainly not a prerequisite. While bitcoins lack 'intrinsic value' in this sense, they make up for it in spades by possessing the other qualities necessary to make it a good medium of exchange, equal to or better than commodity money.

Value is ultimately determined by what people are willing to trade for - by supply and demand.

比特币违法的因为它不是法定货币

Short answer: chickens aren't legal tender either, but bartering with chickens is not illegal.

There are a number of currencies in existence that are not official government-backed currencies. A currency is, after all, nothing more than a convenient unit of account. While national laws may vary from country to country, and you should certainly check the laws of your jurisdiction, in general trading in any commodity, including digital commodities like bitcoin, game currencies like WoW gold or Linden dollars, is not illegal.

比特币是本土恐怖主义，这玩意对美国和美元的经济稳定性有害无益

http://en.wikipedia.org/wiki/Definitions_of_terrorism#United_States 根据这个， you need to do violent activities to be considered a terrorist for legal purposes. This has no bearing on politicians and idiotic US attorney's public remarks.

Also bitcoin isn't domestic. It's a worldwide community. See this map of bitcoin nodes http://forum.bitcoin.org/?topic=2346.0

Bitcoin will only enable tax evaders which will lead to the eventual downfall of civilization

Cash transactions hold the same level of anonymity but are still taxed successfully. It is up to you to follow the applicable state laws in your home country, or face the consequences.

Bitcoins can be printed/minted by anyone and are therefore worthless

Bitcoins are not printed/minted. Instead, Blocks are computed by miners and for their efforts they are awarded a specific amount of bitcoins + transaction fees. See Blocks for more information on how this process works.

比特币没价值，因为它建立在未经证明的密码学上

比特币用到的 SHA256 和 ECDSA 是广为人知的工业标准算法。如果你觉得这些算法不可靠那你就别信比特币，顺带着信用卡和其它电子银行的交易都不能信。

早期参与者赚得也太多了

早期参与者当年花了大把的时间和票子做这种高风险的投资，那些都是他们应得的。

从语义上来说, “公平”是个很随意的概念，不可能在一个广泛的人群中获得共识。 建立“公平”不是比特币的任务，也不可能实现。

两百一十万个比特币中的大部分还没有被分发。现在就开始挖矿，你也能成为早期参与者。

两千一百万个币太少了，形不成规模

一个比特币可以分到小数点儿后八位。 比特币实际上有2,099,999,997,690,000 (超过两万亿)个元单元。

一个BTC代表100,000,000个元单元。换句话说，每个都可以分成10^8份。

1BTC在流通过程中价值会变得越来越大，届时人们可以使用更小的单位，比如毫比(mBTC)或者微比(μBTC)。

比特币存在钱包文件里，终于可以CTR+C-CTR+V赚钱啦！

傻吧你？钱包里存的都是密钥，让你有权花钱而已。就像一个帐号，你办多少个存折都不可能让你的存款翻倍，你办俩送人一个，之后不管谁花钱，帐号里的钱都会变少。

丢了的币没法补回来，好糟糕

比特币可以分到0.00000001，所以这不是个问题。如果你丢了钱，别人的钱就会增值一点点。就当是给所有人捐款了。

一个相关的问题是：为什么没有一个丢失货币的回补机制？答案是“丢失”货币和揣兜里一直不用的好钱完全没法区分。

这是一个巨大的旁氏骗局

在旁氏骗局中, 发起人欺骗参与者会大家共赢。比特币并没有做出过这样的保证。 这里并无中心实体，是个由个体建立起的经济体系。

旁氏骗局是个零和博弈。早期参与者只能从后来者哪里获利。比特币可以实现双赢。早期参与者可以从汇率增值中获利。后期参与者则可享受这种稳定且广泛使用的点对点货币的好处。

Not to be confused with the Bitcoin Randomizer which is a game that really is self-described as a Ponzi scheme.

有限的货币不断的丢失导致恶性通缩

As deflationary forces may apply, economic factors such as hoarding are offset by human factors that may lessen the chances that a Deflationary spiral will occur.

比特币不灵的，没法控制通货紧缩

Inflation is simply a rise of prices over time, which is generally the result of the devaluing of a currency. This is a function of supply and demand. Given the fact that the supply of Bitcoins is fixed at a certain amount, unlike fiat money, the only way for inflation to get out of control is for demand to disappear. Temporary inflation is possible with a rapid adoption of Fractional Reserve Banking but will stabilize once a substantial number of the 21 million "hard" bitcoins are stored as reserves by banks.

Given the fact that Bitcoin is a distributed system of currency, if demand were to decrease to almost nothing, the currency would be doomed anyway.

The key point here is that Bitcoin as a currency can't be inflated by any single person or entity, like a government, as there's no way to increase supply past a certain amount.

Indeed, the most likely scenario, as Bitcoin becomes more popular and demand increases, is for the currency to increase in value, or deflate, until demand stabilizes.

Bitcoin community are anarchist/conspiracy theorist/gold standard weenies

Some are, but the community consists of people with a variety of ideological stances.

只要有足够的计算能力就可以接管整个网络

然，参见Weaknesses。

也就是说，随着网络的增长，个体越来越难实施这个办法。就现在来说，比特币网络的计算能力已经不比世界上最快的超级计算机差了。

就算攻击者一次性接管了整个网络，他也做不了什么大事。他没办法拿走所有人的钱。顶多能将自己的近期付款追回来，或者让他人因为得不到确认而无法付款。这种攻击相当耗资源，为了这点儿蝇头小利。。。谁会做这种赔本的买卖。

比特币犯法的

哪条？

参见法定货币的问题。

Fractional reserve banking is not possible

It is possible. There is no fundamental difference between classical currencies and bitcoin as it applies to banking. Banks will still be free to take in bitcoins and present them to customers as "available for withdrawal" while still lending most of those bitcoins to a different customer for a profit. Some of those bitcoins will be held in reserves in case of a bank run. It will be up to the bank to hold a sufficient supply of reserves in order to prevent insolvency in the event of a bank run. Central banks were established to enforce reserve requirements and so, with bitcoin lacking a central bank, some banks will almost surly collapse, taking their customers' deposits with them.

See Fractional reserve banking.

Conventional banks in the United States guarantee that account holders can withdraw 100% of their dollars based on their "word" and the fact that they are backed up by the FDIC. This program insures depositors up to a certain amount (currently $250K USD per depositor). The FDIC is widely known to have reserves sufficient to cover only a very small fraction of the total deposits it insures though the FDIC itself can be considered to be backed up by the US Congress in the event of its insolvency. After politically desired, the FDIC's role could be extended to insure Bitcoin banks and establish a minimum reserve requirement. Such a change would only happen after public outrage occurs after the inevitable collapse of major Bitcoin banks.

Because Fractional Reserve Banking is possible with bitcoins, the money supply of bitcoins (which includes demand deposits) can greatly exceed 21 million.

要等十分钟才能确认，用比特币在端点销售机神马的付款不给力啊

发款要等几十分钟才能被“确认”，这一特性将来也不会改变。即使将来网络计算的能力比现在大很多，产生一个区块的难度也会自动调整到一小时6个。要想在超市刷比特币的可能办法：

1) 小额付款，假定消费者不会诈骗就行。如果人家只买桶牛奶，看到付款就可以拿走。The transaction should propagate through the network almost instantly, allowing the seller to see the transaction within seconds (albeit with zero confirmations.) The cost of a double-spend attack should make small-scale fraud not worthwhile.

2) Utilize a 'listening' period prior to rendering the service or good. This has yet to be formally implemented in the standard bitcoin client, but would allow a vendor to receive the transaction and then monitor the bitcoin network for a certain period of time (maybe 10 seconds) for possible double spends. Vendors might utilize specialized payment processors with multiple well-connected nodes for this purpose. As explained by Satoshi, the network nodes only accept the first version of a transaction they receive to incorporate into the block they're trying to generate. When you broadcast a transaction, if someone else broadcasts a double-spend at the same time, it's a race to propagate to the most nodes first. If one has a slight head start, it'll geometrically spread through the network faster and get most of the nodes. Therefore, the longer the listening period goes without a double spend attempt, the far less likely a double-spend attempt will actually succeed. If a double-spend is detected, the vendor is notified: no latte.

3) Create a network of transaction hubs. These entities would communicate using a common API. They would float short-term loans between each other to facilitate instant transactions.

Imagine that Alice uses Carol's Clearinghouse as her hub, and Bob uses Dave's Anonymous Exchange. Both Alice and Bob have accounts with their respective hubs, and have already deposited some Bitcoins in their accounts. When Alice wants to buy a latte from Bob at a point of sale, Alice tells Carol "I want to send Bob x Bitcoins. He uses Dave's Anonymous Exchange." After checking that Alice's account does contain at least x Bitcoins, Carol sends a message to Dave, saying "Credit Bob's account with x bitcoins immediately; I'll send you the real Bitcoins in the next block." Bob instantly sees his balance increase, and gives Alice her latte.

As always, trust is required - Alice has to trust Carol, and the hubs have to trust each other. Due to competition, various hubs could develop with vastly different fee structures, membership requirements, trustability, etc.

(But the point of bitcoin is you don't need trust to execute the transaction, in the above description of option 3 you replaced the bitcoins with a trust-based centralized authority.)

等币都挖光了谁还愿意打包啊

When operating costs can't be covered by the block creation bounty, which will happen some time before the total amount of BTC is reached, miners are expected to earn profit from transaction fees.

比特币没有内建的退款机制，好糟糕

为什么有人觉得不好: Chargebacks are useful for limiting fraud. The person handling your money has a responsibility to prevent fraud. If you buy something on Ebay and the seller never ships it, PayPal takes funds from the seller's account and gives you back the money. This strengthens the Ebay economy, because people recognize that their risk is limited and are more willing to purchase items from risky sellers.

为什么实际上是好事: Bitcoin is designed such that your money is yours and yours alone. Allowing chargebacks implies that it is possible for another entity to take your money from you. You can have either total ownership rights of your money, or fraud protection, but not both. That said, nothing prevents the creation of services overlayed on top of Bitcoin that provide fraud protection services.

The statement "The person handling your money has a responsibility to prevent fraud" is still true; the power has been shifted into your own hands. Fraud will always exist. It's up to you to only send bitcoins to trusted entities. It is possible to trust an online identity without ever knowing their physical identity; see the OTC Web of Trust.

量子计算机可以干掉比特币

是的，你拿一台量子计算机干掉它吧。比特币的安全性可以升级- 如果量子计算机真的能被造出来的话。

See the implications of quantum computers on public key cryptography here http://en.wikipedia.org/wiki/Quantum_computer#Potential

The risk of quantum computers is also there for financial institutions, like banks, because they heavily rely on cryptography when doing transactions.

Bitcoin mining is a waste of energy and harmful for ecology

No more so than the the wastefulness of mining gold out of the ground, melting it down and shaping it into bars, and then putting it back underground again. Not to mention the building of big fancy buildings, the waste of energy printing and minting all the various fiat currencies, the transportation thereof in armored cars by no less than two security guards for each who could probably be doing something more productive, etc.

As far as mediums of exchange go, bitcoin is actually quite economical of resources, compared to others.

比特币汇率一天一变，商场营业员没法定价

你在假设比特币可以立即卖出弥补操作开销。If the shopkeeper's back-end expenses were transacted in bitcoins as well, then the exchange rate would be irrelevant. Larger adoption of bitcoins would make prices sticky. Future volatility is expected to decrease, as the size and depth of the market grows.

In the meantime, many merchants simply regularly pull the latest market rates from the exchanges and automatically update the prices on their websites. Also you might be able to buy a put option in order to sell at a fixed rate for a given amount of time. This would protect you from drops in price and simplify your operations for that time period.

Like Flooz and e-gold, bitcoins are great for criminals and so will be shut down

• Hopefully bitcoin will grow to the point where no single organization can disrupt the network, or would be better served by helping it.
• Terrorists fly aircrafts into buildings, but the governments have not yet abolished consumer air travel. Obviously the public good outweighs the possible bad in their opinion.
• Criminal law differs between jurisdictions.

比特币会像当年的自由币（Liberty Dollars）一样会被政府做掉

Liberty Dollars started as a commercial venture to establish alternative US currency, including physical banknotes and coins, backed by precious metals. This, in and of itself, is not illegal. They were later shut down for counterfeiting and intent to fraud after the coins, which contained less than $1 worth of silver, were put into circulation with the general money supply, supposedly having a value of 1 USD. These actions were encouraged by the makers of Liberty Dollars.

Bitcoins are not necessarily equal in value to dollars or any other currency and no one is saying they are. No member of the public will be tricked into accepting a bitcoin instead of a dollar.

Of course, actually 'shutting down' the decentralized Bitcoin network is rife with its own set of difficult considerations.

比特币根本不是去中心化的，开发者可以控制软件

比特币协议最初由其发明者中本聪定义，本协议现已被矿工和用户广泛接受为标准。

虽然比特币官方客户端的开发人员仍然对比特币社区施加影响，但他们任意修改协议的能力是非常有限的。自Bitcoin 0.3版发布以后，该协议只有非常细微的变化，并始终能与社区达成一致意见。

要修改协议，比如将封包奖金从50增加到100块，无法与网络中正在使用中的客户端兼容。如果开发者发布一个客户端，儿多数矿工都觉得它是有害的，或者偏离了整个项目的目标，那个客户端根本火不起来，即使有零星的用户尝试使用，他们的交易也会被整个网络拒绝。

除了“官方”比特币户，其它开发组也可以做自己的客户端（目前在开发中），只要这些客户端遵循比特币协议，官方客户端的开发者无法阻止他们的竞争，因为在网络中根本无法区分哪个是官方客户端。