新聞來源連結：
https://www.ccn.com/bitcoin-gold-hit-by-double-spend-attack-exchanges-lose-millions/
新聞本文：
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A malicious miner successfully executed a double spend attack on the Bitcoin
Gold network last week, making BTG at least the third altcoin to succumb to a
network attack during that timespan.
Bitcoin Gold director of communications Edward Iskra first warned users about
the attack on May 18, explaining that a malicious miner was using the exploit
to steal funds from cryptocurrency exchanges.
To execute the attack, the miner acquired at least 51 percent of the network’
s total hashpower, which provided them with temporary control of the
blockchain. Obtaining this much hashpower is incredibly expensive — even on
a smaller network like bitcoin gold — but it can be monetized by using it in
tandem with a double spend attack.
After gaining control of the network, the attacker began depositing BTG at
cryptocurrency exchanges while also attempting to send those same coins to a
wallet under their control. Ordinarily, the blockchain would resolve this by
including only the first transaction in the block, but the attacker was able
to reverse transactions since they had majority control of the network.
Consequently, they were able to deposit funds on exchanges and quickly
withdraw them again, after which they reversed the initial transaction so
that they could send the coins they had originally deposited to another
wallet.
bitcoin gold
Source: BTG Explorer
A bitcoin gold address implicated in the attack has received more than
388,200 BTG since May 16 (mostly from transactions it sent to itself).
Assuming all of those transactions were associated with the double spend
exploit, the attacker could have stolen as much as $18.6 million worth of
funds from exchanges.
The last transaction was sent on May 18, but the attacker could theoretically
attempt to resume it if they still have access to enough hashpower to gain
control of the blockchain.
Bitcoin gold’s developers advised exchanges to address the attack by
increasing the number of confirmations required before they credit deposits
to customer accounts. Blockchain data indicates that the attacker
successfully reversed transactions as far back as 22 blocks, leading
developers to advise raising confirmation requirements to 50 blocks.
At present, bitcoin gold ranks as the 26th-largest cryptocurrency, with a
circulating market cap of $827 million.
Bitcoin gold is at least the third cryptocurrency network hit with a major
attack in the past week alone.
As CCN reported, a miner manipulated two of privacy coin verge’s five
hashing algorithms to maliciously mine more than 35 million XVG — worth
~$1.75 million — in just a few hours. Previously, Japanese cryptocurrency
monacoin was hit by an apparent block withholding attack after a miner gained
as much as 57 percent of the network’s hashrate.
Featured Image from Shutterstock
評論：
沒想到有機會可以見證到51%算力攻擊

前幾天Verge不是又見證過了嗎xd

XVG日常

還有mona也中標惹其實說是bug造成的51%攻擊說不定比較適合

tcn不要再拖人下水粉飾太平了..跟官方謊稱是ddos有87%像mona和btg被攻擊都是算力被51%壓制 前者selfish後者雙花這是小幣pow無可奈何的弱點但是XVG是因為演算法存在漏洞 攻擊者根本不需要多少算力只用time stamp欺騙就用低算力低難度爽挖走了35M的XVG

有趣的是xvg已經被攻擊過一次了，這次是第二次可能開發者圈夠錢不想再出力了吧

被攻擊不可恥 可恥的是不願意承認錯誤也不認真修正錯誤被用相同手法攻擊只是剛好而已

BTG是被礦機幹掉嗎?XMR和BTG交易所錢包維修挺久的

樓上是哪間交易所? 看你問好多次了XD但話說回來交易所的錢包要修多久也不是dev能控制的阿XD

一貫先噴再說的leftc呢 https://goo.gl/Yz3YVk "timestamp attack" 就是verge遭受的攻擊，沒全部搞懂就愛噴人，你還是去八卦版吧

你根本沒過你自己貼的東西 There is difference as in Verge the timestamp itself was faked跟XVG dev真的是87%像 明明不懂又硬要凹

類似攻擊不行嗎？兩個不同的幣有一模一樣的攻擊喔? 可笑

mona和btg的攻擊都需要夠多的算力 你的文就寫了45%

" quite similar as Verge " 不就無視

bittrex啊,垃圾幣的天堂這家很怪,TUSD可以波動成那樣...

tcn仔細去看下面討論吧..也是被轟跟xvg根本不一樣原po已經承認用詞不佳 similar只是個人觀點 你要繼續凹嗎?"沒全部搞懂就愛噴人"這句還給你自己用吧 你也不是第一次了

Verge不用hashpower就可以駭？我看你根本不在乎技術吧 https://goo.gl/dgv3k9

每次到最後都是自打臉卻還是可以黑人黑得理直氣壯..(聳肩)我根本不用點進去就知道你要講攻擊起始的算力....呵

不懂就不要裝懂噴人，專家才可以用那種口氣說話

要不要比一下跟51%差多少? 要不要講講後續的diff會劇降?

最看不慣翻一兩篇就把自己當專家噴人的leftc 我都是保持討論態度留言就你和camella在亂

左大放輕鬆 認真就輸了

好啦好啦.. 我剛剛兩句問題 你很懂的要回應嗎?

我認真了 抱歉...

噗..一如往常..臉皮厚無敵 我承認我輸惹 吃飯去

硬拗是無法改變XVG有timestamp漏洞的事實

真是一如既往的吵著一如既往的事情ㄋ

就說是XVG日常惹

還好我早出光了 第一次被駭就是警訊

但是xvg被駭之後又漲一波

剛剛點開tcn自以為嗆爆的那篇文 差點沒笑死XDDDDDtcn:Verge不用hashpower就可以駭? 該貼文: 0.4%算力即可只要0.4%算力就可以做到別人51%攻擊的效果 真是不簡單

漲那波每天都等他掉 現在終於跌破賣點.055

一直幫XVG護航並不會改變它是shitcoin的事實

這標準我大概推個廢文都是在幫xvg護航吧 賣光了還能怎辦

tcn1john在前4樓被打臉後，裝做沒事了

光速打臉xDD