Kill Switch Engage: Sia Cryptocurrency to Block Bitmain and Other Big Miners

After nearly a year of acrimonious debate, the Sia blockchain is moving to give big mining companies the boot.

David Vorick, founder and CEO of Nebulous - the for-profit company behind the $233 million distributed storage protocol - told CoinDesk that Sia will soon move to enact a software change meant to block certain types of specialized mining hardware from the platform, allowing hardware manufactured by Nebulous subsidiary Obelisk to remain one of the only ways to collect the blockchain's lucrative cryptocurrency rewards.

"Sia's decided to fork to obsolete or brick the Innosilicon and Bitmain hardware," Vorick said, referring to Obelisk's rival manufacturers of application-specific integrated circuit mining equipment for Siacoin.

In a draft statement on the decision acquired by CoinDesk, Vorick wrote that the company wants to embrace an "ASIC monopoly," arguing the system-wide upgrade, or hard fork - "Is better than resisting ASICs altogether." That said, he added: "We don't believe that a cryptocurrency needs to embrace a parasitic or abusive ASIC monopoly."

Continuing, Vorick emphasized that the code change is optional, and is configured in such a way as to "Enable a group of dissenters to easily split off and be on a separate blockchain where the hard fork was never implemented." According to the blog post, such a split will not impact the functionality of the Sia network.

In his statement and an interview with CoinDesk, Vorick described the motivation and method for bricking Innosilicon's ASIC miners.

Sia's decision is unique in that the goal is not to keep ASICs off the network entirely - Vorick has written that this is a losing battle and diminishes a coin's security - but to block ASICs made by particular companies.

If Innosilicon and Bitmain move as fast as possible to produce new hardware, Vorick told CoinDesk, they may be able to replace the bricked ASICs in three or four months.

To understand the debate that's unfolded - and which this decision may or may not bring to a close - it's necessary to go back to June 2017, when Obelisk was publicly unveiled, along with its plans to sell a Sia ASIC. By December, said Vorick, Sia developers were already receiving "Unverifiable" tips that someone had secretly built their own ASIC and was using it to mine Siacoin.

The following month, Bitmain publicly revealed their Sia ASIC, and it soon became clear that the company had been using it to mine on the network since November.