It appears Bitcoin Gold (BTG) has been double spend attacked over and over again, totalling something in the neighbourhood of $18 million at current prices. BTG forums seem to have been tracking the hack, going as far back as last week, monitoring the controversial coin’s hash rate, ultimately determining a 51% attack was underway.
Bitcoin Gold Gets $18 Million Haircut
“An unknown party with access to very large amounts of hash power is trying to use ‘51% attacks,’” Bitcoin Gold forum poster Mental Nomad announced a week ago, “to perform ‘double spend’ attacks to steal money from Exchanges. We have been advising all exchanges to increase confirmations and carefully review large deposits.”
A founding economic principle of bitcoin was its alleviation of the double spend problem. It was a main stumbling block in the historical race to create a viable cryptographic monetary form – foiling a great many coders along the way. Satoshi Nakamoto solved it through a decentralized, distributed ledger confirmation process (blockchain). Going as far back as its genesis block from early 2009, users can be confident transactions aren’t rebroadcast. Like clockwork, 6 times an hour, blocks are added – copied to nodes within the universal network.
One way to achieve double spending is known as a 51% attack. It’s accomplished by bogarting the network’s computing power. With a majority, bad actors can get between the Nakamoto solution and transaction confirmations. By stymieing block completion in the usual manner, all sorts of mischief can arise: blockchain mining rewards redirected, users’ transactions reversed, etc. Not too long after, a double spending attack can commence, acting as the fiat equivalent to counterfeiting. Needless to type, any crypto suffering from such a problem is certain to immediately lose user confidence.
Such attacks are interesting for another reason, as Mental Nomad is careful to point out. “There is no risk to typical users or to existing funds being held. The only parties at risk are those currently accepting large payments directly from the attacker. Exchanges are the primary targets,” he assured last week. “It appears that actions on the part of the exchanges have deterred the attacker, for now.” And hitting exchanges tends to elicit little sympathy, at least initially, due to users being insulated. Exchanges are particularly vulnerable because they generally covet large deposits, which only compounds the problem in cases like these.
Over period of days, batches of BTG were deposited into exchanges supporting the forked coin, only to be sent back to the depositor’s wallet. The lag between such a transaction and some exchanges’ discovery is sufficient enough to nab tokens, doubling the filthy lucre. Exchanges trading bitcoin gold have responded by upping transaction confirmation filters, but evidently to no avail as the attacker gains ever-more BTG network control.
Bitcoin Gold team members seem to have communicated with some exchanges. “Requiring more confirmations greatly increases safety,” the forum details. “Until now, some Exchanges were operating with less than five confirmations required. We have been urging higher limits to prevent such an attack, and urging manual review of large deposits of BTG before clearing the funds for trading.” Indeed, according to BTG, “One of the targeted Exchanges reported that they strongly believe this attacker attempted to hit them with a double-spend of BTC in the past. In their words, ‘we are 100% sure that it is the same person, we found many associations between the accounts.’”
Evidence put forward by the BTG team points to address GTNjvCGssb2rbLnDV1xxsHmunQdvXnY2Ft as the attacker’s wallet; mined coins, according to the forum post reside at GXXjRkdquAkyHeJ6ReW3v4FY3QbgPfugTx. More than 388,201.92404001 BTG were funneled through the wallet, totalling more than $18 million according to Bitcoin Gold Explorer. That a top thirty crypto by market cap can be so easily troubled is a giant of enough problem, but it could also take exchanges down in the process – something the ecosystem is very sensitive to since Mt. Gox. And though, for now, BTG is confident enough to suggest users are not at risk, history shows that can quickly be the case as an exchange freezes withdrawals in an effort to stop hemorrhaging.
Bitcoin Gold has been beset by controversies since its birth fork late last year, including a recent dust-up between BCH advocate Craig Wright and BTG founder Jack Liao. To be fair, however, it is not the only blockchain to suffer a 51% attack. Mere days ago, recently Chinese government highly rated coin verge (XVG) was made to heel, again. These pages reported XVG, “On the morning of May 22, Suprvona, one of the largest altcoin mining pools, informed its 19,000 Twitter followers that verge was suffering yet another 51% attack, causing all blocks to be rejected.”
Images via Pixabay, BTG Block Explorer.
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