Bitcoin Coders Confront an Old Quandary: How to Upgrade an Entire Network

An old debate is resurfacing in the bitcoin developer community, underscoring one of the critical challenges facing decentralized systems: how to update the software when ostensibly no one's in charge.

How does the whole network smoothly upgrade in a way that's backward-compatible, allowing those with older versions of the software to continue participating? What's the best way for bitcoin to make this type of change without disruption?

"There are a series of soft-fork designs which have recently been making good progress towards implementation and future adoption. However, for various reasons, activation methods ... have gotten limited discussion," Bitcoin Core contributor Matt Corallo wrote in an email to the bitcoin developers' list last month that reopened the debate.

The root of the idea is that bitcoin users and exchanges should decide whether a change should go through, and miners would follow their desires - not the other way around.

Without getting into the weeds, the takeaway for some bitcoin developers was that UASF was a better way to enact changes.

At the time, Rusty Russell, a developer at bitcoin startup Blockstream, went as far as to apologize for playing a part in constructing BIP 9."I hadn't expected that this checkpoint would be used as a chokepoint to ransom the network. This significantly changes the risk model; BIP-8 is now a far superior method for network upgrades, where miners can only accelerate the process, not block it," he wrote in a Medium post.

Alex Bosworth, a developer at startup Lightning Labs, expressed a similar opinion, based partly on recent drama surrounding bitcoin cash, a smaller cryptocurrency that split off from bitcoin in 2017.A sizable group of bitcoin cash mining pools recently proposed that some BCH from each new block should go to a development fund, which Bosworth sees as another example of mining pools flexing their muscles in a way that's bad for cryptocurrency decentralization.

Urging caution, worry that looking to UASFs as the sole activation method could open the possibility of pushing through changes that could hurt bitcoin.

"Developing bitcoin is not a race. If we have to, waiting 42 months ensures we're not setting a negative precedent that we'll come to regret as bitcoin continues to grow," he said.

The community will need to decide on something before the change can be added to bitcoin, building more privacy into the network.