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Bitcoin Gold (BTG) was 51% attacked

Bitcoin Gold (BTG) was 51% attacked


Bitcoin Gold is a Bitcoin hard-fork that aims to be GPU-mineable by using the Equihash algorithm with parameters (144, 5) also known as "Zhash". The Bitcoin Gold website claims Zhash "uses more memory than an ASIC can muster, but runs fine on many graphics cards". Bitcoin Gold was previously 51% attacked in May 2018 when it was estimated that up to $18 million worth of BTG was double-spent.

The Attacks

Between Thursday and Friday we detected two deep reorgs on BTG, both of which contained double-spends. Their details are listed below. All times are GMT.

In both cases the attacker blocks were mined with the address GWrW5dTZf5XwGWoJuqRKdzkzZFkwtWSqaP in the coinbase transaction. We note that at the time of the attack, on Binance deposits of BTG were credited to one's account for trading after six confirmations, and were available for withdrawals after twelve confirmations. A fourteen or fifteen block reorg would thus evade both of Binance's escrow periods. Binance has since increased their withdrawal requirement for BTG to twenty confirmations. Based on Nicehash market price data for Zhash we estimate the cost of generating each reorg at around 0.2 BTC (~$1,700) and the attacker would have recouped around the same value in block rewards. Therefore, it is possible that the attacks were profitable if the double-spends succeeded at defrauding the attacker's counterparty, or break-even if the double-spends were unsuccessful. This suggests that a confirmation requirement on the order of tens of blocks for BTG is still far too few to make the budget constraint to launch an attack significant.

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OK, but BTG didn't "fork off from bitcoin."

BTG stood up a completely independent network with new nodes and new miners. It was impossible (by design) for Bitcoin miners to follow the BTG fork, which required entirely different hardware. There was exactly zero contention within Bitcoin as to whether to support Bitcoin or BTG.

BTG did fork Bitcoin's blockchain history as a fair basis for the initial distribution of 16.5 million BTG, true. But there was never contention or competition with Bitcoin, so there is no "landslide victory" or loss.

There was even a 20-day pause between the blockchain snapshot and the first BTG block. I don't see how this can be viewed as a competition.

Snapshot of BTC blockchain: October 23, 2017, block 491407
First BTG block mined: Nov 12, 2017, block 491408

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Now I read the comments of 2019, when many did not take seriously and did not think that bitcoin would reach the price of 40 k dollars, not to mention 64 k)) Times have changed and now cryptocurrencies have caught up with the authorities very quickly and very well. Elon Musk and other millionaires, billionaires have started to invest very large amounts of money in cryptocurrencies, and this leads to higher prices. I personally invested on platform 10 k dollars in several cryptocurrencies and now I am waiting for growth. I have expectations of a minimum profit of $ 20k, but I hope it will be more. I am waiting ))

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I didn't have time to thank you earlier - so, thanks for the work and contribution of information. by The way Twisting is possible in Cyrptocurrsy

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