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429 points AbhishekParmar | 2 comments | | HN request time: 0.028s | source
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Imnimo ◴[] No.45670761[source]
As with any quantum computing news, I will wait for Scott Aaronson to tell me what to think about this.
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lisper ◴[] No.45670978[source]
Why wait? Just go read the paper:

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.

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ransom1538 ◴[] No.45671003[source]
SO... BTC goes to zero?
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bilsbie ◴[] No.45671360[source]
I don’t see why bitcoin wouldn’t update its software in such a case. The majority of minors just need to agree. But why wouldn’t they if the alternative is going to zero?
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andrewla ◴[] No.45671613[source]
How could updating the software possibly make a difference here? If the encryption is cracked, then who is to say who owns which Bitcoin? As soon as I try to transfer any coin that I own, I expose my public key, your "Quantum Computer" cracks it, and you offer a competing transaction with a higher fee to send the Bitcoin to your slush fund.

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.

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1. orblivion ◴[] No.45671904[source]
Firstly I'd want to see them hash the whole blockchain (not just the last block) with the post-quantum algo to make sure history is intact.

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.

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2. ◴[] No.45672016[source]