Will Bitcoin Hardfork over Quantum?

[Agiravax]

Protective Hardfork is as disruptive and anyway mandatory first to freeconsensus of those against softfork.
Along with Asian miners.

Ah, so your argument is that a softfork to increase blocksize for a BIP-360-style quantum improvement would not be accepted, and thus the hardfork is the only option?

Blocksize can only be increased with hardfork.

Softfork-only path only means you won't be able to afford a mainchain wallet anymore.

There is no speculation. Only 2 options :

1) Introduce signatures via softfork-only into hell
2) Hardfork blocksize before to avoid hell

[dkbit98]

It's been a while since we had any bitcoin fork, so it's not impossible to see one happening in next few years.
I am not worried so much about Quantum computers but it would be wise to prepare and be ready if threat become serious.
Problem is that nobody is making quantum resistant banks and financial system, and if everything else crashes, bitcoin is also going down.
I am sure enough people would support another btc fork just because they would get some free coins again

[Agiravax]

It's been a while since we had any bitcoin fork, so it's not impossible to see one happening in next few years.
I am not worried so much about Quantum computers but it would be wise to prepare and be ready if threat become serious.
Problem is that nobody is making quantum resistant banks and financial system, and if everything else crashes, bitcoin is also going down.
I am sure enough people would support another btc fork just because they would get some free coins again

Banks don't have to try to find consensus towards guaranteed economic death...

[PX-Z]

It will without doubt hardfork to a quantum-resistant algorithm, at some point. The real questions are (1) which algorithm that is (2) how many years it will take and (3) whether vulnerable coins will be frozen or not.

A softfork with post-quantum signature schemes might be proposed and applied first, but if the assumed damage of the quantum computation is enough to considered as a threat, a hardfork is higher chance. But the timeline? It won't happen in 5 year, probably 10 years before this quantum computers are built, usually these kind of computers are built for different purposes not to disrupt the whole internet since it will be affected as well lmao

[Agiravax]

A softfork with post-quantum signature schemes might be proposed and applied first, but if the assumed damage of the quantum computation is enough to considered as a threat, a hardfork is higher chance. But the timeline? It won't happen in 5 year, probably 10 years before this quantum computers are built, usually these kind of computers are built for different purposes not to disrupt the whole internet since it will be affected as well lmao

As explained, Hardfork comes first and softfork-only is economic dead end.
The only threat is other chains being quantum safe soon as Bitcoin stucked in consensus besides would be loosing ranking.
Until it Hardforks to safety.

Are you sure you guys understand Bitcoin?

[ABCbits]

Blocksize can only be increased with hardfork.

That's not true. It's proven with SegWit, which upgrade maximum block size from 1 MB to 4 million weight unit which allow block size up to 4MB. Although personally i see it's as crude approach.

[0x000369]

As explained, Hardfork comes first and softfork-only is economic dead end.The only threat is other chains being quantum safe soon as Bitcoin stucked in consensus besides would be loosing ranking. Until it Hardforks to safety.Are you sure you guys understand Bitcoin?

lol @Agiravax sounds like you just want free coins with another hardfork
the whole quantum fud is still years away anyway who cares right now
and this idea that softforks are an economic dead end is just fud
segwit was a softfork and it increased block capacity a hardfork isn't the only way to scale or add new features
you think a hardfork guarantees "sovereignty" but most people cant even run a node anyway
bitcoin's value comes from its immutability and slow careful changes not reckless forks every time someone gets scared about something hypothetical

[Agiravax]

lol @Agiravax sounds like you just want free coins with another hardfork
the whole quantum fud is still years away anyway who cares right now
and this idea that softforks are an economic dead end is just fud
segwit was a softfork and it increased block capacity a hardfork isn't the only way to scale or add new features
you think a hardfork guarantees "sovereignty" but most people cant even run a node anyway
bitcoin's value comes from its immutability and slow careful changes not reckless forks every time someone gets scared about something hypothetical

I only care about what is Bitcoin.

Is a centralized and Institutions-exclusive Gold chain really the end goal?
Is it even a reliable business model in practice or only economic death by fees suffocation?

Or should Bitcoin protect individual sovereignty?
Protects the status quo? Keep chain open to all as it is now.

It's about where this is going not about fiat value.

[Agiravax]

Blocksize can only be increased with hardfork.

That's not true. It's proven with SegWit, which upgrade maximum block size from 1 MB to 4 million weight unit which allow block size up to 4MB. Although personally i see it's as crude approach.

Segwit has introduced a 4Mo blockhead but it only increases effective blocksize to 1.5Mo
Currently mainchain process >1500 tx/block for a max blocksize capacity of ~4000.

Quantum signatures are 50-100x heavier than ECDSA.
Signature introduction (even if hybrid or deffered) would ultimately result to 100 tx/block capacity. Well bellow current average.
Fee market will turn highly volatile and expensive. Mempool will saturate.

While this behavior seems expected, it's impact on chain stability and accessibility may turn repulsive once live.

Also signature introduction is irreversible in practice. Won't be removed during quantum era...
It's '' only trying to make Bitcoin something else as slowly, sneakily and quietly as possible.

Therefore softfork-only becomes as disruptive as a protective Hardfork would be..

[Rustam Meraj]

Fight between Bitcoin future as company or self run system has heated up in early February 2026 when technical choices of super computer protection become unavoidable. Addition of new age signs may increase use size by 10x to 40x, and Layer 1 fees have to reach into thousands, which will push about half of user group into less self run Layer 2 fixes.

To my taste, this stress increases chances of a Network Split. Companies and ETFs will continue to ask for easy selling version of Split that updates support, but there will also be split called Self-Run that may draw in those who value being spread out and low cost holding it yourself. So when old chain is turned into rich person only network with large amount of traffic, Power War might start money escape to a more friendly split, with trillions of dollars placed on market chance.

[d5000]

Segwit has introduced a 4Mo blockhead but it only increases effective blocksize to 1.5Mo

Yes, and that's because it's only the witness field where the weight discount is applied (the witness field holds ... signatures! (and public keys/redeem/taproot scripts)).

But ... you can do the same thing with a dedicated "post quantum witness" field ... and you can increase it to the size you want. (That was the whole point of my previous posts!)

And you would then be able to keep the exact same tx capacity (1500 / block).

The only problem is that this new witness space could be misappropiated perhaps for data storage (just like Ordinals did). But you would have the same problem with a hardforked blocksize increase.

By the way:

Ah, so your argument is that a softfork to increase blocksize for a BIP-360-style quantum improvement would not be accepted, and thus the hardfork is the only option?

Blocksize can only be increased with hardfork.

Sorry to think your post was more intelligent than I initially thought

[BlackHatCoiner]

Is a centralized and Institutions-exclusive Gold chain really the end goal?

This argument might just be the one that I've seen being brought the most in this place. People always complain about how bitcoin was "hijacked" or how it "stalled" and ended up an "institution-exclusive goldchain", lol. The conclusion that bitcoin remained this way is never that there was actual consensus taking place. 

At least don't screw this quantum-thread with just another endless scaling problem discussion. People made up their minds about this long ago. Bitcoin will not have millions of transactions per second on the base layer. Ever. And there won't be scaling problem with the quantum-resistant algorithm either.

[ABCbits]

Blocksize can only be increased with hardfork.

That's not true. It's proven with SegWit, which upgrade maximum block size from 1 MB to 4 million weight unit which allow block size up to 4MB. Although personally i see it's as crude approach.

Segwit has introduced a 4Mo blockhead but it only increases effective blocksize to 1.5Mo
Currently mainchain process >1500 tx/block for a max blocksize capacity of ~4000.

Looking at past 1 year data on https://statoshi.info/d/000000002/blocks?orgId=1&from=now-1y&to=now&timezone=browser, average block size is slightly above 1.5MB. But the average TX per block is about 2900.

Quantum signatures are 50-100x heavier than ECDSA.
Signature introduction (even if hybrid or deffered) would ultimately result to 100 tx/block capacity. Well bellow current average.
Fee market will turn highly volatile and expensive. Mempool will saturate.

While this behavior seems expected, it's impact on chain stability and accessibility may turn repulsive once live.

Also signature introduction is irreversible in practice. Won't be removed during quantum era...
It's '' only trying to make Bitcoin something else as slowly, sneakily and quietly as possible.

Therefore softfork-only becomes as disruptive as a protective Hardfork would be..

Ii'm aware some QC resistant signature have much bigger size or computation requirement. But at least for size issue, you can increase the discount factor on SegWit. Currently it's only 4, but it could be much higher.

[Agiravax]

This argument might just be the one that I've seen being brought the most in this place. People always complain about how bitcoin was "hijacked" or how it "stalled" and ended up an "institution-exclusive goldchain", lol. The conclusion that bitcoin remained this way is never that there was actual consensus taking place.  

At least don't screw this quantum-thread with just another endless scaling problem discussion. People made up their minds about this long ago. Bitcoin will not have millions of transactions per second on the base layer. Ever. And there won't be scaling problem with the quantum-resistant algorithm either.

Well eventually some still understand that a highly congested chain is only an unusable chain in practice.
Not a reliable business model and not an healthy open Infrastucture. Only economic death by fees suffocation.

With all other chains starting to go ahead with their quantum roadmap, and all of them starting with Hardforking Blocksize, the market will start to understand...

While there will be no soft path that will avoid extreme congestion.
Consensus is impossible then.

What will start as "contentious Hardfork" will turn into "Protective HardFork" up to "Sovereign Bitcoin"
Nodes are not fully suicidal.

"Economic death or Hardfork ?"
Will then become their ultimate choice.

Once the cost of doing nothing becomes clear, the harder path no longer seems unrealistic...
It starts to feel necessary.