立即打开
“双重支付”谣言引担忧,比特币价格一度重挫

“双重支付”谣言引担忧,比特币价格一度重挫

骆杰峰(Jeff John Roberts) 2021年01月28日
如果存在“双重支付”的可能性,那么所有人都将有理由对比特币失去信心,其币值也会直线下跌。

今年1月21日,比特币(Bitcoin)一度跌破30,000美元,虽然在当天晚些时候有所反弹,但跌幅仍然达到了15%。这并不是比特币价格第一次出现大幅波动,甚至波动本身也是比特币的标志之一,但由于这次暴跌系“比特币存在双重支付问题”的谣言所引发,所以格外引人注目。

大多数的普通比特币买家对“双重支付”事件并不熟悉,但防止“双重支付”对加密货币的完整性至关重要。如果存在“双重支付”的可能性,那么所有人都将有理由对比特币失去信心,其币值也会直线下跌。

那么,到底什么是“双重支付”呢?顾名思义,双重支付就是将同一批比特币支付两次,同时篡改交易记录(也就是所谓的区块链),从而蒙混过关。目前尚无证据表明此前曾经发生过这种事件。

在传统金融领域,与比特币“双重支付”最贴近的例子是,某人使用支票购买东西,然后再在卖家兑现支票前将存款从银行账户中取出。

不过,与支票不同,比特币的接受方不必信任比特币的支付方。相反,比特币用户依靠比特币的软件网络(分散在世界各地的成千上万台电脑)来验证交易的合法性。

就像自动取款机会向用户收取提现费用一样,运营比特币网络的所谓“矿工”通常也会要求用户支付类似的“比特币转账手续费”。但与自动取款机不同的是,比特币转账的手续费取决于网络的繁忙程度。在1月21日发生的事件中,某位用户在试图转账少量比特币时,一开始并未支付足够的手续费。

由于手续费不足,矿工就忽视了1月21日的这笔交易,于是前述用户便提高了手续费,重新发布了交易请求。这一次,网络上的一位矿工决定接手处理新发布的交易,但巧合的是,另一名矿工同时决定处理原始交易。

结果就是用户在这一瞬间似乎将同一笔比特币转账了两次,但这其实只是一种错觉,因为在设计上,比特币网络就只会识别一批交易(这些交易被称为“区块”,约每十分钟添加一个)。因此,虽然在这一瞬间用户似乎将自己的比特币支付了两次,但在其中一笔交易成为区块链(即2009年比特币上线后所有比特币交易的公开、不可篡改记录)组成部分的同时,另一笔交易迅速遭到忽视。

熟稔比特币的人士很快就意识到1月21日的事件是一个“无效事件”,但部分媒体还是借机进行了一波炒作,写文章暗示确实发生了“双重支付”事件。与此同时,Bitcoin SV(一种口碑不佳的空气币,与比特币存在竞争关系)的部分支持者扮演了煽风点火的角色。

以上种种情况导致市场出现了像银行挤兑(由于对银行的偿付能力失去信心,客户会在资金全部耗尽前排队取出自己的存款)一样的短暂恐慌。不过,就比特币而言,这一事件更加突显了数字货币的设计具有远超以往的安全性。虽然怀疑论者可以给出各种原因,说明比特币目前的价格水平为什么不可持续,但双重支付缺陷显然不在其中。(财富中文网)

译者:梁宇

审校:夏林

今年1月21日,比特币(Bitcoin)一度跌破30,000美元,虽然在当天晚些时候有所反弹,但跌幅仍然达到了15%。这并不是比特币价格第一次出现大幅波动,甚至波动本身也是比特币的标志之一,但由于这次暴跌系“比特币存在双重支付问题”的谣言所引发,所以格外引人注目。

大多数的普通比特币买家对“双重支付”事件并不熟悉,但防止“双重支付”对加密货币的完整性至关重要。如果存在“双重支付”的可能性,那么所有人都将有理由对比特币失去信心,其币值也会直线下跌。

那么,到底什么是“双重支付”呢?顾名思义,双重支付就是将同一批比特币支付两次,同时篡改交易记录(也就是所谓的区块链),从而蒙混过关。目前尚无证据表明此前曾经发生过这种事件。

在传统金融领域,与比特币“双重支付”最贴近的例子是,某人使用支票购买东西,然后再在卖家兑现支票前将存款从银行账户中取出。

不过,与支票不同,比特币的接受方不必信任比特币的支付方。相反,比特币用户依靠比特币的软件网络(分散在世界各地的成千上万台电脑)来验证交易的合法性。

就像自动取款机会向用户收取提现费用一样,运营比特币网络的所谓“矿工”通常也会要求用户支付类似的“比特币转账手续费”。但与自动取款机不同的是,比特币转账的手续费取决于网络的繁忙程度。在1月21日发生的事件中,某位用户在试图转账少量比特币时,一开始并未支付足够的手续费。

由于手续费不足,矿工就忽视了1月21日的这笔交易,于是前述用户便提高了手续费,重新发布了交易请求。这一次,网络上的一位矿工决定接手处理新发布的交易,但巧合的是,另一名矿工同时决定处理原始交易。

结果就是用户在这一瞬间似乎将同一笔比特币转账了两次,但这其实只是一种错觉,因为在设计上,比特币网络就只会识别一批交易(这些交易被称为“区块”,约每十分钟添加一个)。因此,虽然在这一瞬间用户似乎将自己的比特币支付了两次,但在其中一笔交易成为区块链(即2009年比特币上线后所有比特币交易的公开、不可篡改记录)组成部分的同时,另一笔交易迅速遭到忽视。

熟稔比特币的人士很快就意识到1月21日的事件是一个“无效事件”,但部分媒体还是借机进行了一波炒作,写文章暗示确实发生了“双重支付”事件。与此同时,Bitcoin SV(一种口碑不佳的空气币,与比特币存在竞争关系)的部分支持者扮演了煽风点火的角色。

以上种种情况导致市场出现了像银行挤兑(由于对银行的偿付能力失去信心,客户会在资金全部耗尽前排队取出自己的存款)一样的短暂恐慌。不过,就比特币而言,这一事件更加突显了数字货币的设计具有远超以往的安全性。虽然怀疑论者可以给出各种原因,说明比特币目前的价格水平为什么不可持续,但双重支付缺陷显然不在其中。(财富中文网)

译者:梁宇

审校:夏林

Bitcoin fell around 15% on January 21, briefly tumbling below $30,000 before rallying later in the day. This is hardly the first time the price has swung wildly—volatility is Bitcoin's hallmark—but Thursday's events are notable because they were partly triggered by false rumors of an existential event: a double-spend.

A "double-spend" incident is unfamiliar to most casual Bitcoin buyers, but preventing one is crucial to the integrity of the currency. If double-spends are possible, then everyone would rightfully lose confidence in Bitcoin and the price would go into free fall.

So what exactly is a double-spend? As the name implies, it means spending the same batch of Bitcoin twice, while tampering with the transaction record, known as blockchain, to get away with it. There is no proof such an incident has ever happened.

In the world of traditional finance, the best analogy to double-spending Bitcoin is someone writing a check to buy something, then withdrawing money from their bank account before the seller can cash it.

Unlike the act of writing check, however, someone receiving Bitcoin funds doesn't have to trust the person paying them. Instead, Bitcoin users rely on the currency's software network—thousands of computers scattered around the world—to verify a transaction is legitimate.

What happened on January 21 involved a user who tried to sent a small amount of Bitcoin but failed to attach a sufficient transaction fee. Just like ATMs charge people for withdrawing cash, the so-called miners who operate the Bitcoin network typically demand a similar fee to send Bitcoin. But unlike ATMs, the Bitcoin fee fluctuates depending on how busy the network is.

In the case of the transaction on January 21, the miners initially ignored it, leading the user to post it again with a higher fee. This time, one of the miners decided to accept the transaction—but, by coincidence, a different miner at the very same time decided to process the original transaction.

The upshot is that, for a very brief time, it looked like the user got to send the same Bitcoin twice. This was an illusion, however, because the Bitcoin network is designed so that it only recognizes one batch of transactions (the batches are known as blocks with a new one being added every ten minutes or so). So even though it briefly appeared that the user had spent his or her Bitcoin twice, one of those transactions was quickly ignored while the other became part of the blockchain—the public, immutable record of all Bitcoin transactions since the currency launched in 2009.

Those very familiar with Bitcoin quickly recognized January 21's incident as a non-event. But that didn't stop some media outlets writing headlines that suggested a bona fide double-spend had occurred. Meanwhile, some boosters of a poorly-regarded rival cryptocurrency—a knock-off called Bitcoin SV—fanned the rumors.

All of this led to a brief panic like the bank runs of old—when customers who lost confidence in a bank's solvency would line up to withdraw their savings before the funds were all gone. In the case of Bitcoin, though, Thursday's effort just underscored how the design of the digital currency is stronger than ever. And while skeptics can point to reasons why Bitcoin's current price levels are not sustainable, the risk of a double-spend flaw is not one of them.

最新:
  • 热读文章
  • 热门视频
活动
扫码打开财富Plus App