Even a year ago it was totally fair to question the feasibility of CRQCs. After all the recent scientific and engineering wins, that is not in question anymore. Eventual arrival of CRQC is pretty much a consensus now in quantum and cyber communities.
But that question is almost irrelevant now. The world is acting like CRQCs are coming, so we should act like it too. Regulators and governments are issuing quantum readiness roadmaps, banks have started their programs, insurers are carving out quantum risks, shareholders and analysts are questioning quantum readiness on earnings calls… and the media is eating it all up. The general public awareness is rapidly growing.
Rightly or wrongly, users will soon expect to see some assurances or plans on how bitcoin will resist the quantum threat. And if our response is that a few on the list think CRQC are laughable, the confidence will take a big hit.
The proposed BIP makes lots of sense. With that and BIP-360, a plan is shaping. And then we need three almost independent discussions:
1. We could technically solve Phase C (Post-Quantum Legacy Recovery) for any
impacted BIP-39 wallets. This is the (relatively) easy one.
2. How do we make it all a bit more “crypto-agile”?
3. And finally the philosophical discussion on how to treat
legacy non-HD wallets - burn them or allow them to be “stolen” / “liberated”.
Hi Peter,
I think everyone here is well-aware of the possibility
that CRQCs may not ever appear, but that doesn't change
the fact we must have a plan ready to handle them. Lopp's
proposal does exactly that, and in a way that can be
rolled out incrementally as the risk increases. And even
if CRQCs never break discrete log, we would do well to
invest the time in designing this migration path anyway.
We'd then have a playbook to handle other sources of
cryptanalytic breakthroughs in the future.
I think you're worried the community may jump the gun and
deploy a freezing upgrade like phases A or B too early. I
share your concern but if anything I suspect the opposite
will happen. Nobody is going to be willing to freeze
anything unless imminent danger is readily apparent, and
fear-based reactions kick in.
Once it does, things will happen fast, and we need a plan
ready for that day (if it comes).
regards,
conduition
On Saturday, July 19th, 2025 at 8:13 AM, Peter Todd <pe...@petertodd.org> wrote:
> On Mon, Jul 14, 2025 at 02:52:17PM -0400, Jameson Lopp wrote:
>
> > Correct, this time is different in that we're not talking about vague
> > unknown weaknesses. Rather, we're talking about a known algorithm that
> > makes breaking cryptographic primitives orders of magnitude cheaper.
>
>
> We already have known algorithms that would break cryptographic primitives if
> sufficiently good analog computers actually existed. Or for that matter, "split
> the universe" brute forcing. No-one is worried about them because "sufficiently
> good" analog computers and multiverses are widely belived to not be physically
> realizable.
>
> For all the claims of progress on quantum computing hardware, the fact still
> remains that no-one is even close to demonstrating cryptographic-relevant
> quantum computing capabilities and the actual cryptographic-relevant
> capabilities of real hardware are laughable. It's still an unknown whether or
> not they are physically possible, and outside of the part of the physics
> community that would like to sell you a quantum computer - or research
> developing one - they're widely belived to be not physical.
>
> Hence, these are still vague unknown weaknesses. Until progress is less vague,
> actively freezing peoples' coins is not going to happen.
>
> --
> https://petertodd.org 'peter'[:-1]@petertodd.org
>
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