Bitcoin Cash is facing a potential hash war between backers of the ABC and SV implementations, possibly resulting in disruption or even a chain split.

The contention lies between two competing implementations of Bitcoin Cash: Bitcoin ABC, which intends to implement a variety of improvements to the network, and Bitcoin SV, which focuses on a more streamlined approach and a significantly increased block size. SV is mainly backed by nChain and CoinGeek, while ABC counts support from, Coinbase, Binance, and variety of others. The community remains split, and according to Coin Dance’s tally of company support, the ABC roadmap appears to be ahead. OpenBazaar lead backend developer Chris Pacia sees the user support clearly on the ABC side, indicating that value will follow the chain with the most users:

In terms of mining hashpower, however, outcome is less certain, with CoinGeek and SVPool comprising nearly 30% of the last 24 hours’ blocks.

An eerie warning of total destruction

The coming hashpower contest could prove ugly and destructive if parties involved are taken at their word. In a series of tweets, nChain chief scientist Craig Wright issued a strongly-worded threat against the competing ABC client, intimating that he would see to its permanent and total failure:

“A note. Many like to treat me like Casandra. Well, here is your warning to ignore at your peril. We will win this fast, or we will win this slow, but, we will win this. Others would like this to be “nicer”, I would prefer a lesson. I want to have people understand Bitcoin. If it means we spend a year or more slowly bleeding every satoshi of value one by one from the ABC chain, we will. Without exception.

If ABC stays on SHA256d and does not add replay protection, we will hound it. Not until it is weak, not until it is unlisted on every miner and major and home level exchange globally, but until the last CPU running it anywhere globally burns out. If this means chasing a lone dev with a CPU to burn that last vestige of hope, and you think I will not, then, you do not know me! But, you will learn. This is not vengeance. It is a lesson. And I intend to burn it into the hearts and souls of all the socialists in ABC so their great grand children do not forget it!

Have a nice day.”

While the outcome of the hard fork is not clear, and not all parties involved may see Wright’s threats as credible, CoinText CTO Vin Armani expressed belief that the hashpower accrued by CoinGeek and nChain would be sufficient to cause significant damage. Armani released a video on Twitter calling for the hash war to be averted:

Notably, Armani called attention to the potential threat of affiliated miners also conducting similar attacks on other proof-of-work chains, disrupting those networks until their market value and viability significantly decreased.

Hash wars highlight need for governance, need for security model improvements

The emergence of increasingly contentious internal community struggles draws attention to the need for improved governance and consensus systems. Dash has yet to have experienced a similar disruption because controversial decisions can largely be resolved with a masternode vote. The issue of on-chain scaling was voted on in early 2016, with a big-block approach approved by a near-unanimous majority. Earlier this year, a proposal seeking to remove Dash Core leadership over a series of disagreements failed with a nearly 10-1 ratio of approval vs. disapproval. Similar functions in other coins could help resolve community splits before the threat of a hash battle becomes a relevant or necessary option.

The Bitcoin Cash hash war does, however, demonstrate a potential fragility of proof-of-work for security. A recently launched mining pool service promises to maliciously mine empty blocks of other cryptocurrencies to hamper other chains:

Whether or not the threat is credible, it does draw attention to the potential for large mining operations and manufacturers to attack and disrupt proof-of-work cryptocurrencies. Dash’s founder Evan Duffield previously hinted at introducing some manner of collateral requirement for miners in the future, though no public plans to introduce such a requirement have been announced at this time.