As with any quantum computing news, I will wait for Scott Aaronson to tell me what to think about this.
replies(6):
https://www.nature.com/articles/s41586-025-09526-6
In the last sentence of the abstract you will find:
"These results ... indicate a viable path to practical quantum advantage."
And in the conclusions:
"Although the random circuits used in the dynamic learning demonstration remain a toy model for Hamiltonians that are of practical relevance, the scheme is readily applicable to real physical systems."
So the press release is a little over-hyped. But this is real progress nonetheless (assuming the results actually hold up).
[UPDATE] It should be noted that this is still a very long way away from cracking RSA. That requires quantum error correction, which this work doesn't address at all. This work is in a completely different regime of quantum computing, looking for practical applications that use a quantum computer to simulate a physical quantum system faster than a classical computer can. The hardware improvements that produced progress in this area might be applicable to QEC some day, this is not direct progress towards implementing Shor's algorithm at all. So your crypto is still safe for the time being.
It would be a pain to manage but it would be safe from quantum computing.
Where is the exact threat?
No amount of software fixes can update this. In theory once an attack becomes feasible on the horizon they could update to post-quantum encryption and offer the ability to transfer from old-style addresses to new-style addresses, but this would be a herculean effort for everyone involved and would require all holders (not miners) to actively update their wallets. Basically infeasible.
Fortunately this will never actually happen. It's way more likely that ECDSA is broken by mundane means (better stochastic approaches most likely) than quantum computing being a factor.
A nice benefit is it solves the problem with Satoshi’s (of course not a real person or owner) wallet. Satoshi’s wallet becomes the defacto quantum advantage prize. That’s a lot of scratch for a research lab.
Any rational economic actor would participate in a post-quantum hard fork because the alternative is losing all their money.
If this was a company with a $2 trillion market cap there'd be no question they'd move heaven-and-earth to prevent the stock from going to zero.
Y2K only cost $500 billion[1] adjusted for inflation and that required updating essentially every computer on Earth.
But as far as moving balances - it's up to the owners. It would start with anybody holding a balance high enough to make it worth the amount of money it would take to crack a single key. That cracking price will go down, and the value of BTC may go up. People can move over time as they see fit.
So we are all in a collective flap that someone can see my bank transactions? These are pretty much public knowledge to governments/central banks/clearing houses anyway -- doesn't seem like all that big a deal to me.
(I work on payment processing systems for a large bank)
As far as i am aware, eliptic curve is also vulnerable to quantum attacks.
The threat is generally both passive eavesdropping to decrypt later and also active MITM attacks. Both of course require the attacker to be in a position to eavesdrop.
> Let’s say you crack the encryption key used in my bank between a java payment processing system and a database server.
Well if you are sitting in the right place on the network then you can.
> how do you mitm this traffic?
Depends on the scenario. If you are government or ISP then its easy. Otherwise it might be difficult. Typical real life scenarios are when the victim is using wifi and the attacker is in the physical vicinity.
Like all things crypto, it always depends on context. What information are you trying to protect and who are you trying to protect.
All that said, people are already experimenting with PQC so it might mostly be moot by the time a quantum computer comes around. On the other hand people are still using md5 so legacy will bite.
if you can read the TLS session in general, you can capture the TLS session ticket and then use that to make a subsequent connection. This is easier as you dont have to be injecting packets live or make inconvinent packets disappear.
Not really. This would be if not instantly then when a batch goes for clearing or reconciliation, be caught -- and an investigation would be immediately started.
There are safeguards against this kind of thing that can't be really defeated by breaking some crypto. We have to protect against malicious employees etc also.
One can not simply insert bank transactions like this. They are really extremely complicated flows here.
I think this is all overhyped though. It seems likely we will have plenty of warning to migrate prior to achieving big enough quantum computers to steal wallets. Per wikipedia:
> The latest quantum resource estimates for breaking a curve with a 256-bit modulus (128-bit security level) are 2330 qubits and 126 billion Toffoli gates.
IIRC this is speculated to be the reason ECDSA was selected for Bitcoin in the first place.
Somehow, I'm not all that scared. Perhaps I'm naive.. :}
These are fairly robust systems. You'd likely have a much better impact dossing the banks.
[1] - https://github.com/jlopp/bips/blob/quantum_migration/bip-pos...
So I do not think these tools or economic substrate layers are going anywhere. They are very valuable for the particular kinds of applications that can be built with them and also as additional productive layers to the credit and liquidity markets nationally, internationally, and also globally/universally.
So there is a lot of institutional interest, including governance interest, in using them to build better systems. Bitcoin on its own would be reduced in such justification but because of Ethereum's function as an engine which can drive utility, the two together are a formidable and quantum-resistant platform that can scale into the hundreds of trillions of dollars and in Ethereum's case...certainly beyond $1Q in time.
I'm very bullish on the underlying technology, even beyond tokenomics for any particular project. The underlying technologies are powerful protocols that facilitate the development and deployment of Non Zero Sum systems at scale. With Q-Day not expected until end of 2020s or beginning of 2030s, that is a considerable amount of time (in the tech world) to lay the ground work for further hardening and discussions around this.
It doesn't require all holders to update their wallets. Some people would fail to do so and lose their money. That doesn't mean the rest of the network can't do anything to save themselves. Most people use hosted wallets like Coinbase these days anyway, and Coinbase would certainly be on top of things.
Also, you don't need to break ECDSA to break BTC. You could also do it by breaking mining. The block header has a 32-bit nonce at the very end. My brain is too smooth to know how realistic this actually is, but perhaps someone could do use a QC to perform the final step of SHA-256 on all 2^32 possible values of the nonce at once, giving them an insurmountable advantage in mining. If only a single party has that advantage, it breaks the Nash equilibrium.
But if multiple parties have that advantage, I suppose BTC could survive until someone breaks ECDSA. All those mining ASICs would become worthless, though.
I don't see why it wouldn't look like normal traffic.
> Somehow, I'm not all that scared. Perhaps I'm naive.. :}
We're talking about an attack that probably won't be practical for another 20 years , which already has counter measures that are in testing right now. Almost nobody should be worried about it.
It should be noted that according to IonQ's roadmap, they're targeting 2030 for computers capable of that. That's only about 5 years sooner than when the government has said everyone has to move to post quantum.