《The Sidechains Breakthrough Almost Everyone in Bitcoin Missed》
《比特幣世界幾乎都沒有察覺的側鏈技術突破》

[Alyssa Hertig]
Jan 17, 2018 at 05:00 UTC

You've heard of proof of work, but what about proofs of proofs of work?
想必你聽說過工作量證明了，那么工作量證明的證明呢？

A complex notion, the research on "Non-Interactive Proofs of Proofs of Work," or NiPoPoW, released in October, has received very little attention so far but is heralded as breaking through one of the major roadblocks that has stalled the widely anticipated sidechain technology.
這是一個有點復雜的概念，一項對于“非互動工作量證明之證明”批钠，或簡稱NiPoPoW的研究成果于10月發(fā)布，盡管目前并無多少人關注悉默，但卻被預言可能突破那些阻礙廣受期待的側鏈技術進展的其中一個難點间螟。

In the paper, researchers from IOHK, IC3 and the University of Athens describe a mechanism for proving that data exists in the bitcoin blockchain in a more efficient way.
在白皮書中纤垂，來自IOHK夕晓，IC3和雅典大學的研究者們描述了一種機制宛乃，可用更高效的方式來驗證比特幣區(qū)塊鏈中存在的數(shù)據(jù)。

Though the idea can be useful in more than one context, it's perhaps most exciting in the way the researchers describe the proofs' benefits for sidechains, a technology that pegs other blockchains to bitcoin, which some, because of its obstacles, have called vaporware, but that others refer to as the "altcoin killer."
這個想法在不少場景中都很有用蒸辆，但最讓人覺得興奮的莫過于研究者們描述的征炼，該證明機制對側鏈技術的幫助。側鏈技術是一種可將其他區(qū)塊鏈錨定到比特幣區(qū)塊鏈上的技術躬贡，被人們稱為“競爭幣殺手”谆奥，但因為各種障礙也被一些人稱為“霧件”（看得見卻摸不著產(chǎn)品或服務）。

Sidechains seek to solve a vexing problem – that adding features to bitcoin is a dangerous process since $230 billion of value is at risk if the new feature doesn't work or malfunctions in practice.
側鏈技術尋求的是解決一個老大難的問題——在比特幣上增加功能困難重重逗宜，如果新功能不起作用或者在運行中失靈了雄右，那對這個2300億美元市值的幣種是非常危險的事情。

Instead of adding new features directly to the bitcoin blockchain, sidechains allow developers to attach new features to a separate chain. Since the chains are still attached to the bitcoin blockchain, the features can take advantage of the cryptocurrency's network effects and test those applications, without harming the main network should vulnerabilities arise.
比起在比特幣的區(qū)塊鏈上直接添加功能纺讲，側鏈技術可讓開發(fā)者們在一條單獨的鏈上添加新功能。因為這些側鏈還是錨定在比特幣區(qū)塊鏈上囤屹，所以這些新功能可以利用加密貨幣的網(wǎng)絡效應并測試這些應用熬甚，同時又不傷及主網(wǎng)絡的脆弱性。

Because of this, sidechains were met with excitement initially, but has faced contention since many have concerns about the security of the technology.
正因如此肋坚，側鏈技術在最初很令人興奮乡括，但隨著不少人擔心該技術的安全性也遭遇到爭論。

Even still, some engineers have been grinding away at a parallel version of the technology that tries to rely on better economic incentives to make sidechains more secure, yet some developers remain skeptical they're ready to add to the bitcoin network.
甚至當一些工程師轉而去開發(fā)一個相似的版本智厌，并試圖依靠更好的經(jīng)濟激勵方式讓側鏈更加安全诲泌，卻還是受到了一些開發(fā)者質疑他們是否已準備好可被添加到比特幣網(wǎng)絡中。

But skeptics see this NiPoPoW research as a big step.
但如今懷疑者們也將NiPoPoW的研究看做重要的一步铣鹏。

Blockstream's Mark Friedenbach, who co-authored the original sidechains white paper, first proposed in 2014, told CoinDesk:
Blockstream的Mark Friedenbach敷扫，是2014年發(fā)布的側鏈技術初始白皮書的合著者，他告訴Coindesk：

"This moves the ball down the field significantly."
"這讓球在球場上起了很大變化"

Securing sidechains

加固側鏈

The paper helps move forward the idea of trustless sidechains, over the more centralized type of sidechains – where the movement of funds of a federated sidechain is governed by a few companies – used today.
這論文將去信任化的側鏈技術的想法向前推進了诚卸，超越了如今多在使用的中心化類型的側鏈技術葵第，這種側鏈技術結成聯(lián)盟绘迁，其中的少數(shù)公司掌控了資金的流動。

While a simple idea, trustless sidechains are hard to put into practice.
但同時卒密，這個簡單的想法—去信任化的側鏈技術還很難實用起來缀台。

They rely on a technology called SPV (simplified payment verification) proofs, which work like this: in order to send money to a sidechain and back to the main bitcoin network again, users need to attach a proof that they really have the funds. Without these proofs, when users or miners move their money back to the main chain, under certain conditions, they could take more money than they really have.
因為側鏈技術依靠一個稱為SPV（簡單支付驗證）證明的技術，它是這么運行的：為了向側鏈中發(fā)送資金并且返回到比特幣主網(wǎng)中哮奇，用戶需要隨附一份他們確實有這些資金的證明膛腐。若沒有該證明，當用戶或者礦工將資金移回主鏈時鼎俘，在某種情況下依疼，他們可以取走比實際更多的資金。

These proofs need to do two things before the technology can be added to bitcoin: one, prevent this sort of theft, and two, be small enough that they can actually be sent over the network.
在該技術可被添加到比特幣上之前而芥，這“證明”需要完成兩件事情：1.防止這種類型的盜竊行為律罢，2.需要足夠小巧，來確保他們可被發(fā)送到網(wǎng)絡中棍丐。

While so-called "compact SPV proofs" have been proposed, they've proved vulnerable to certain attacks, ones that would potentially allow miners to steal money left on the sidechains.
可當所謂“堅固的SPV證明”被提出之時误辑，它們也被證明了在一些攻擊面前還很脆弱，其中一些攻擊讓礦工們有可能竊取側鏈中的資金歌逢。

Yet, the proof outlined in the NiPoPoW paper claims to be resistant to these attacks.
不過在NiPoPoW中提出的證明框架宣稱能抵擋這些攻擊行為巾钉。

"It's the first protocol, to my knowledge, which makes [sidechains] secure at all," University of Athens cryptography Ph.D. candidate Dionysis Zindros, one of the co-authors of the paper, told CoinDesk.
“以我所知，這是第一個可使側鏈技術徹底變得安全的協(xié)議秘案，”雅典大學加密學博士生Dionysis Zindros如此告訴CoinDesk砰苍，他也是該論文的合著者。

He went on to explain that by "secure" he really means resistance to double spending, where users or miners could spend their coins more than once.
他繼續(xù)解釋說“安全”是指真的可以抵抗雙重支付阱高，就是用戶或者礦工可以把他們的貨幣使用不止一次赚导。

"It's really a missing piece in sidechain constructions that we fill in," Zindros said.
“我們所填補的真的是側鏈結構中缺失的一部分〕嗑”Zindros說到吼旧。

Friedenbach described the change in more technical terms: "This is a big step towards defining a block header commitment structure that allows for log-sized chain proofs, of the sort that one might use in a decentralized sidechains implementation."
Friedenbach用更多科技術語來描述：“這對定義區(qū)塊頭的承諾結構是重要的一步，因為可讓側鏈證明以日志文件的大小存在未舟，而這是一個去中心化的側鏈技術更可能實施的類型條件圈暗。”

Work ahead

奮發(fā)進取

While Friedenbach calls NiPoPoW "good research," he added, work remains before the technology can be deployed on bitcoin.
當Friedenbach稱NiPoPoW為“好的研究”的時候裕膀，他補充道员串，在該技術能在比特幣中部署之前，還有很多工作要完成昼扛。

This is a recurring theme in the cryptocurrency world, where developers are careful about making changes to the still young and novel code. And while sidechains look to make the process of trying out new features easier and less nerve-wracking, implementing even that will take further deliberation.
這在加密貨幣的世界里是一個反復的話題寸齐，因為這個領域的開發(fā)者們對在仍然小眾與早期的代碼中做改變是非常謹慎的。即便側鏈技術看起來讓嘗試新功能的過程變得更容易更不那么令人心煩，在其中實施仍然很需要長遠的思考访忿。

For one, to make sidechains more secure, many developers believe merge-mining – when miners mine multiple coins at the same time – would be essential.
比如說瞧栗，為了讓側鏈技術變得更加安全，很多開發(fā)者相信共同挖礦—就是礦工們同時挖不同的貨幣—也就變得很重要了海铆。

"There is still significant scripting capabilities that would be required before merge-mined SPV-proof sidechains could be supported on bitcoin mainnet," Friedenbach said.
“在比特幣主網(wǎng)支持基于共同挖礦的SPV證明側鏈技術以前迹恐，還需要很重要的代碼開發(fā)能力，”Friedenbach說道卧斟。

But there are other worries around merge-mining that are more paramount.
不過圍繞著共同挖礦還有其他更深的擔憂殴边。

"There is also, of course, the non-trivial incentive problem of merged-mining and whether such a solution would be a step back in security, given the current state of the oligarchical mining industry," Friedenbach added.
“當然還有包括共同挖礦的可觀的激勵問題，以及這種方案會不會是安全性上的倒退珍语，考慮到現(xiàn)在挖礦業(yè)中的寡頭情況锤岸。”Friedenbach說道板乙。

In many's view, since the industry relies on the work of a few large mining pools, it could be possible for these miners to have significant control over sidechains, and it's not yet clear whether mining pools would have the power to steal funds.
在大多數(shù)人的看法中是偷，既然該產(chǎn)業(yè)依賴于少數(shù)幾個大礦池的運作，那么這些礦工們也很可能對側鏈技術進行嚴重的控制募逞，到目前還不清楚礦池有沒有能力竊取資金蛋铆。

That said, this piece of the puzzle is exciting to Friedenbach, even though buzz around the paper has been subdued.
總而言之，這塊拼圖讓Friedenbach感到十分興奮放接，盡管圍繞著該論文還有不少的議論之聲刺啦。

He concluded:
他總結到：

"This idea deserves more attention."
“這個想法值得更多的關注”

*Disclosure: CoinDesk is a subsidiary of Digital Currency Group, which has an ownership stake in Blockstream. *