Bitmain has never used the AsicBoost exploit on the Bitcoin mainnet, the company said in an official statement today.
Furthermore, testing had shown AsicBoost was not a viable option, Bitmain said in a blog post to its website.
“Bitmain has tested ASICBOOST on the Testnet but has never used ASICBOOST on the mainnet as implied in Gregory Maxwell’s proposal. We ask conclusive proof from whoever claims this to be false because such baseless claims are toxic for the Bitcoin space. We also believe the math used by Gregory Maxwell is incorrect and that the method is not practical in a production environment.”
The post added that other manufacturers’ hardware has the same ability. Bitmain owns the AsicBoost patent in China and could legally deploy it to profit from its own mining centers and cloud mining contracts. However, the company said it “is not something we would do for the greater good of Bitcoin.”
Technically, by using the exploit Bitmain could make its own mining operations more energy-efficient (and thus more profitable) than the same equipment it sells to the public.
Bitcoin’s Latest Battleground
Big money, egos and clashing incentive structures have all tested Bitcoin’s economy in recent years. AsicBoost is its latest manifestation.
The issue dominated the news a day earlier after Bitcoin Core developer Maxwell revealed a “major manufacturer” of mining hardware had built the ability to use AsicBoost into its chips. The community assumed this manufacturer was Bitmain, and no-one denied this.
Maxwell did not accuse Bitmain by name, or say it had actually used the exploit. However, his reverse-engineering of ASIC chips had revealed “an undocumented, undisclosed ability to make use of this attack.”
Using AsicBoost would make chips incompatible with proposed changes, particularly SegWit, he said, and suggested another BIP to counter it.
No Evidence AsicBoost Exploitation
Security expert and Cornell University computer science professor Emin Gün Sirer appeared to back up Bitmain’s defense.
On his blog, he wrote there is “absolutely no independently confirmed evidence of ASICBOOST actually being used on any chip.” If there had been, the blockchain would show ample evidence that an algorithm was selecting suitable transactions. However, his random examination of AntPool-mined blocks showed only the usual fee-per-byte method of selection.
AntPool is Bitmain’s own mining pool operation.
He added that developing more efficient mining hardware is hardly an attack. Other mining improvements, such as 16nm chips and better algorithms, could actually include AsicBoost to improve efficiency further.
Implementing SegWit ASAP is not the inevitable solution to AsicBoost, he continued, saying, “there is a history of reputational attacks against people who have spoken up against Segwit.” Countless other, non-controversial solutions could also disable the exploit if desired.
Companies will try to influence Bitcoin to maximize their role in the ecosystem, his post noted. “We call this capitalism.”
An ‘Engineering Optimization’ That All Can Use
Bitmain agreed that there are better ways to resolve Maxwell’s concerns over AsicBoost without “adversarial thinking.” The method does not represent a “covert attack” and is an engineering optimization that can bring greater efficiency to all users.
The company’s statement concluded with another call to scale Bitcoin with increased transaction block sizes:
“We have very firm belief that the block size of Bitcoin will be increased. It is the Bitcoin that our co-founders signed up for, it is the roadmap designed by Satoshi and it is the destiny of Bitcoin. We will protect it at any cost.”
Do you agree with Bitmain and Emin Gün Sirer? Let’s hear your thoughts in the comments.
Images via Pixabay, Twitter