比特幣面臨分裂風險

上周五，幾家大型加密貨幣交易平臺聯(lián)合發(fā)布聲明，宣布了他們對于比特幣可能出現(xiàn)分裂的處理決定。這種分裂被稱作“硬分叉”（hard fork）。多年來，比特幣領(lǐng)導者在這種貨幣的網(wǎng)絡(luò)技術(shù)限制和對未來的愿景上爭執(zhí)不休，愈演愈烈，分裂的可能性也日益增大。

上周五發(fā)布聲明的包括大型門戶網(wǎng)站BitStamp和Kraken，他們表示，如果出現(xiàn)硬分叉，他們會允許用戶交易這兩種傳統(tǒng)比特幣，以及任何可能出現(xiàn)的新版比特幣。最有可能拆分的方案叫做Bitcoin Unlimited。它近期獲得了全球最大的比特幣服務(wù)器組，也就是“挖礦組織”的支持。

比特幣之所以被推向分裂，主要是各方對于所謂的“區(qū)塊大小”（block size）爭執(zhí)不下。按照現(xiàn)有的代碼，比特幣每批交易的數(shù)據(jù)容量有嚴格限制，隨著比特幣熱度日增，這種限制拖慢了交易，以往只需數(shù)秒就能清算，現(xiàn)在得花上好幾個小時。各方都認為有必要對此做出改變。

然而，對于改變的目標和方式，大家卻沒有達成共識。一位比特幣的企業(yè)家很好地總結(jié)了兩派的分歧：Bitcoin Unlimited一派希望升級比特幣，支持更多的小規(guī)模交易，而Bitcoin Core一派則認為不應(yīng)如此大刀闊斧，他們希望交易少一點，讓系統(tǒng)更加穩(wěn)定。

比特幣的管理十分松散，甚至有些無政府主義，這讓改革難以推行。比特幣主機（“礦工”）本質(zhì)上可以通過選擇運行的軟件來對系統(tǒng)的改變進行“投票”。然而如果許多礦工運行了互不兼容的代碼，就會產(chǎn)生不同的交易記錄，實際上也就意味著創(chuàng)造了完全不同的貨幣。

Silicon Angle指出，目前有近40%的比特幣礦工支持Bitcoin Unlimited。這個比例還不足以迫使比特幣進行大規(guī)模的系統(tǒng)性改變，采納新協(xié)議，不過也足夠形成一個舉足輕重的派別了。

交易平臺這次的聲明可能有助于減緩潛在的硬分叉引發(fā)的混亂。去年，加密貨幣已經(jīng)有了類似先例，影響力堪比比特幣的Ethereum為了阻止黑客獲得數(shù)百萬美元的貨幣，按照計劃進行了分裂，卻意外地形成了兩個相互競爭的系統(tǒng)，據(jù)報道，它們會彼此干擾對方的運作。

如果比特幣中最具影響力的成員決定分道揚鑣，那么提前做好規(guī)劃看起來是最合適的選擇。（財富中文網(wǎng)）

作者：David Z. Morris

譯者：嚴匡正

On Friday, a group of major cryptocurrency exchanges announced their planned response to the split of bitcoin into two separate pools of currency and processing power. That event, known as a “hard fork,” is viewed as increasingly likely among bitcoin leaders, as a years-long debate about the network’s technical limitations and broader vision comes to a head.

The marketplaces, including marquee portals BitStamp and Kraken, said on Friday that if a hard fork occurs, they will let users trade both conventional bitcoin, and any alternate version that emerges. The most likely bitcoin spinoff is known as Bitcoin Unlimited, which the world’s largest bitcoin server group, or “mining pool,” recently announced it would back.

Bitcoin has been pushed to the verge of this split by a years-long debate about what’s known as block size. Under bitcoin’s existing code, there’s a tight limit on the amount of data that can be included in a batch of transactions, and as the network has grown in popularity, that limit has slowed the processing of payments. Moves that once took seconds to clear can now take hours, and all players seem to agree that some sort of change is necessary.

But there are competing visions about any fix’s goals and methods. One bitcoin entrepreneur has summarized the divide as between a Bitcoin Unlimited contingent updating bitcoin to support many small transactions, and a Bitcoin Core cadre who believe in smaller changes, fewer transactions, and more stability.

The decentralized, even anarchistic nature of bitcoin administration makes the process of change unwieldy. Bitcoin hosts (“miners”) essentially ‘vote’ on any system changes by choosing what software to run. But if large groups choose to run mutually incompatible code, they generate separate transaction records, and in essence, entirely separate pools of currency.

Currently, according to Silicon Angle, nearly 40% of bitcoin miners support Bitcoin Unlimited—not enough to force a system-wide changeover to the new protocol, but enough to establish a splinter group.

The exchanges’ announcement may help smooth the potential chaos of a hard fork. The crypto world got a preview last year when Ethereum, a major bitcoin alternative, underwent a planned fork to reverse the results of a multimillion dollar hack. That unexpectedly led to two competing systems, which reportedly interfered with one another's operations.

If bitcoin’s big players want to go their separate ways, then, some advance planning seems very healthy.