Submitted via IRC for SoyCow1984
Cryptocurrency trading portal Coinbase delisted today the Ethereum Classic (ETC) currency after detecting a series of double-spend attacks over the last three days.
In layman terms, double-spend attacks are when a malicious actor gains the majority computational power inside a blockchain, which they then use to enforce unauthorized transactions over legitimate ones.
According to a security alert published today by Coinbase security engineer Mark Nesbitt, this is exactly what's been happening on the Ethereum Classic blockchain for the past three days, since January 5.
[...] The ETC cryptocurrency was created in August 2016, shortly after the infamous DAO hack, and was one of the first forks of the more established Ether (ETH).
[...] Update, January 8, 06:00 AM ET: Bitfly, a fellow cryptocurrency trading platform, has also confirmed Coinbase's report. So did the Ethereum Classic team, which was immediately criticized for not spotting the attack on its own network in the first place. Coinbase, too, was criticized, but for failing to reveal the double-spend attacks on Saturday when they first happened, leaving ETC users at risk for three days, for no good reason. Coinbase also updated its original report with details on another 12 double-spend attacks, bringing the total of stolen funds to 219,500 ETC (~$1.1 million).
(Score: 2) by rigrig on Wednesday January 09 2019, @10:33AM (6 children)
You left out the next sentence, which is quite important:
The point is that an attacker could make a net profit in cryptocoins, but they would become worthless once people realize that the attacker controls the blockchain and refuse to exchange them for anything. At that point he would be stuck with a whole lot of worthless bits and a bunch of mining hardware.
In this case someone managed to double-spend 219,500 ETC (~$1.1M), Coinbase found out about it and stopped trading ETC.
So the attacker may very well have made a profit, as long as they cashed in in time:
Now they cashed out twice, and (assuming all faith in ETC is forever gone) it cost them the mining rewards for the alternative chain, because those are now worthless bits.
No one remembers the singer.
(Score: 2, Insightful) by Anonymous Coward on Wednesday January 09 2019, @12:09PM (2 children)
(Score: 3, Insightful) by VLM on Wednesday January 09 2019, @12:19PM
Also consider competing cryptocurrencies.
(Score: 2, Informative) by khallow on Wednesday January 09 2019, @03:27PM
They still need to get the gear. It costs money to destroy money. Every budget has limits and the benefits to destroying cryptocurrencies are greatly overstated.
And there are ways to make the needed threshold of compromise much higher than 50%.
(Score: 2) by deimtee on Wednesday January 09 2019, @03:57PM (2 children)
There is also the possibility of whatever the equivalent of short-selling is. Isn't there some exchange now trading futures on cryptocurrencies?
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 0) by Anonymous Coward on Wednesday January 09 2019, @04:19PM
As long as there are fools and their monies and the potential to separate the two, there will be futures markets.
(Score: 0) by Anonymous Coward on Wednesday January 09 2019, @04:53PM
http://cfe.cboe.com/cfe-products/xbt-cboe-bitcoin-futures [cboe.com]