Bitcoin is in a state of emergency – or, at least, the community thinks so.
Tensions are high as bitcoin’s long-standing scaling debate escalated this week, with some miners talking openly about forcing a possible bitcoin fork that could result in two competing coins.
If that’s not enough of a concern, some miners have even been discussing a possible attack on the old blockchain once they move on to mining the new one – dialogue that has prompted concerning statements from exchanges and other industry startups.
It’s unclear if either will happen, and others aren’t terribly concerned, with some going as far as to describe the recent frenzy as an attempt at price manipulation.
But amid all this, developers seem to be at least responding to community pressures, putting forth creative, if controversial, solutions, such as a way of making upgrades to bitcoin that depends on the economy rather than mining pools.
Another idea is even starting to take shape that might be best considered an emergency measure should miners be serious about forcing a system upgrade.
The thought is that, if such a subsequent attack were to occur, then developers could go so far as to propose a switch to bitcoin’s proof-of-work algorithm that would hobble today’s miners by rendering their current computer hardware redundant.
While Bitcoin Core developers might not agree on much, they do have an aversion to forks without near unanimous support. This algorithm switch, though – recently taking shape into a more formal proposal called Bitcoin Proof-of-Work Initiative (complete with a website and a Twitter account) – requires one.
One developer even called it a “likely” course of action, at least in the right circumstances.
James Hilliard, a developer and technician at Bitcoin mining supply company BitmainWarranty, told CoinDesk:
“If enough miners were to, say, fork Bitcoin Unlimited and attack the non-forked chain without the support of the community then the likely response would be to change proof-of-work.”
In conversation, Bitcoin Core developers stressed the fact that such discussions are exploratory – and that they remain unconvinced this threat of a fork is any different than similar efforts in the past.
Still, it seems like efforts are underway that take strategic planning forward.
“Everything’s on the table,” Core contributor Eric Lombrozo said.
Solidifying an idea
The idea that bitcoin could replace its consensus algorithm is an older one, with Bitcoin Core contributor Luke Dashjr coding up a prototype for such a change last year.
“It’s nothing new, it’s sort of the assumed contingency plan for dealing with miners going against the wishes of the users,” Hilliard said.
Further, the concept is common in other blockchain networks – for example, ethereum plans to switch from proof of work to an alternative further down its roadmap.
But, its apparent popularity in bitcoin might be new, with recent events giving the idea new life. Developers seem to think, if miners fork and end up attacking the old network (as rumored), that this would be the right emergency situation to deploy it.
A perhaps less popular idea, though, is that the network already needs the change.
“The mere existence of an entity with control of over 50% [of the network] is a problem warranting a change,” said Dashjr.
As further evidence the idea is evolving quickly, BitTorrent inventor Bram Cohen pointed out that switching the algorithm is possible with a soft fork – a backwards-compatible way to make the change.
Still, despite support, it remains a contentious idea.
Vice-chairman of the board at the blockchain technology company BitFury Group George Kikvadze went as far as to tweet that his company would hire lawyers to sue developers working on such a change.
“[W]e will spare no resources,” he wrote.
Others have called developers promoting such an algorithm swap hypocritical, since they’ve been opposed to such big bitcoin changes in other circumstances. Still, supporters see it as a necessary last resort.
Pseudonymous Bitcoin Core contributor BTCDrak told CoinDesk:
“A PoW change will not happen unless miners attack the bitcoin chain, make no mistake, it won’t happen without a crisis to justify it.”
One mining pool leader agreed.
“In response to post-split attack with intention to kill original chain, changing PoW would be the best option at that moment,” SatoshiLabs co-founder and CEO Marek Palatinus, who runs Slush Pool, tweeted.
Indeed, right now, the impetus seems to be discussion of a potential post-fork attack, though whether or not the proposal will be put into play remains to be seen.
Stepping back a bit, ETH Zürich computer science PhD student Arthur Gervais pointed out that such a fork, if used, would only addresses a symptom of what he called a larger problem.
“[T]his doesn’t really solve the problem of mining pools or the potential to build ASICs. It would be a temporary ‘quick fix’,” he said.
Gervais pointed to experimental projects that might have longer-term promise in tackling aspects of mining centralization. SmartPool, for example, is a pool in the process of being built using ethereum smart contracts. Another paper outlines a new mining puzzle that could discourage miners from forming mining pools.
Still, some bitcoin developers seem to want to send a message to miners in the near term.
“[T]his is a reason why it’s not in the best interest for miners to push for a controversial fork.”
Correction: An earlier version of this article misstated Kikvadze’s title. This has been corrected.