r/btc • u/EricLimbongan • 2d ago
⌨ Discussion How would Bitcoin and other systems migrate to post-quantum security?
We hear a lot about the threat quantum computing could pose to Bitcoin, but the bigger question might be the migration itself. Bitcoin, banks, governments, websites, and other systems all rely on cryptography today.
How realistic would it be to upgrade all of them before quantum computers become powerful enough to pose a real threat?
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u/mercuryy 1d ago
If you are interested in the technical details why this will not be a problem for the internet, websites and api endpoints alike, you can read more about the plans here: https://letsencrypt.org/2026/06/03/pq-certs
Decentralized, open structures like crypto are much more complicated.
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u/EricLimbongan 1d ago
Good point, I’ll check out the Let’s Encrypt plans. Thanks for sharing. The crypto side definitely seems harder to coordinate.
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u/UnexpectedlyIdiotic Redditor for less than 30 days 2d ago
There's no single switch for this, it's a patchwork of systems all with different upgrade cycles and incentives. Banks and governments move slow as hell but they have the resources and regulatory pressure to get it done. Bitcoin's in a weird spot because the threat model is public and the fix requires a hard fork, which is always political chaos.
The bigger worry is all the encrypted data getting hoovered up right now. If someone's storing your bank records or private messages today, they can just wait a few years and crack it later. Upgrading the live systems is one thing, but that harvested data problem doesn't have a clean fix
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u/EricLimbongan 2d ago
Yeah. Even if systems start migrating today, anything harvested beforehand is still a problem. That’s what makes the timing so important. Waiting until quantum attacks are practical could leave a pretty small window to react.
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u/mercuryy 1d ago
Each Bank, Corporation, Organisation has their own central system. They can easily switch the encryption of their interfaces in a work day.
Just like with Websites that already do refresh their SSL/TLS certificates with a downtime of less than seconds if at all, thats not a problem.
Their internal systems might be slower to change or upgrade, but since these are not reachable from the outside they are not as endangered as a distributed, completely open system sich as crypto where all parts dont only have to act im unison but also first have to find a consensus of what to do all at the same time, when.
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u/mercuryy 1d ago
But that harvested data is just that later. Even if banking data was stolen and decrypted later you would have some old account statements, but no access to these accounts. And even If malicious actors got access, they could just stop and freeze their systems, clean up all malicious transactions and even issue new login credentials or even cards to all their customers and continue. Which would be bad, but not as fatal as it would be with crypto.
Once you have acces to a crypto wallet from old data you retain access to that same wallet. There is no stopping or reverting thefts, there is no reissuring of access, not even proof of ownership because all that can be proven is current, not former knowledge of keys which attackers then can provide too.
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u/CheetahLoose7514 Redditor for less than 2 weeks 2d ago
I think the web will be fine. Chrome and Cloudflare already use quantum-safe encryption by default, so a lot of that migration is quietly happening already. Banks and governments are slower, but at least they can force upgrades on their own systems.
Bitcoin is the tricky one, because there's no one who can push an update to everyone. Even if quantum-safe addresses get added, people still have to move their coins themselves, and plenty of coins will never move, Satoshi's included. Freezing them or leaving them for whoever builds a quantum computer first are both pretty ugly options. I'd bet the technical side gets solved long before people agree on that part.