Quantum computers and Bitcoin security concerns

Hey everyone! No need to freak out, that headline was just for clicks. Your BTC is still secure. So, a quantum computer did manage to crack a bitcoin security feature, but it was just a tiny 15-bit key. That’s pretty trivial since bitcoin relies on 256-bit encryption. Basically, it’s like picking a toy lock when trying to get into a bank vault. But there’s something worth mentioning; this new test is 512 times larger than the last one, which should definitely make us think. Quantum computers aren’t just science fiction anymore. They might be closer than we thought. If you’re holding long-term, keep yourself updated on bitcoin’s progress. This whole experiment was done by Giancarlo Lelli on a public quantum computer, and he got 1 BTC from Project Eleven for his work.

Quantum is one of those threats where nothing matters for years, then suddenly the boring migration work you ignored becomes very expensive. Bitcoin has time, but time is only useful if people spend some of it preparing instead of turning every discussion into either doom cult or cope theater. Also, small nit: Bitcoin is not simply "256-bit encryption." The relevant part here is signatures and public keys, mainly ECDSA today and Schnorr for Taproot. Hashes are a different bucket. Coins sitting in normal modern address types are not the same exposure profile as old P2PK outputs or addresses where the pubkey has already been revealed by spending. That distinction matters a lot when people start making scary charts with glowing atoms in the background.

Imagine building something that can improve the medical field for years to come But their concern is Bitcoin. Like it's the only thing to the cyber threat of quantum computers. They didn't crack Bitcoin They cracked a way lower version of the math behind Bitcoin. It shows quantum is growing which we know But isn't an imminent threat now. It pose a lesser threat than picking a path towards post quantum security.

This is an important feat. This puzzles are like a "canary in the mine" about the power of a quantum computer. It cpould have been solved anytime, instead it was solved now, when the attention is maximum on the topic. Wondering if we will see and acceleration of these news in the coming days. Every lesser porwerful CRQC can now have profit, whitout expecting it to breack SHA-256.

About Bitcoin security and how super hard to brute force Bitcoin private keys, this graphic is very helpful in visual explanation. There are 2^256 private keys out there: how big is that number? Image source. https://learnmeabitcoin.com/beginners/guide/private-keys/ https://github.com/bitcoinbook/bitcoinbook/blob/develop/ch04_keys.adoc

I think quantum computer has never been treated as a myth. On the contrary, it's a certainty. It's an on-going development. What's being treated as a myth is the rumor that quantum computers would break Bitcoin. It's based on the wrong presumption that Bitcoin is static, that it's a sitting duck and could only lay helpless in the face of fast computing developments. Bitcoin is upgrading. It's developing as well. It could turn quantum-ready, upgraded to become quantum-resistant, long before the development of quantum computer reaches a certain level which realistically threatens Bitcoin's security.

Bitcoin is a lively project with most massive community from developers to users so this blockchain has global development contributions over time. It's not a dead or static project that remains the same as it is since the Bitcoin blockchain launch with genesis block. With massive developments decentralized globally and a biggest community in blockchain industry, it's a truly leader in this industry with strongest ability to adapt to any attacking threats. Quantum computer is one of threats that try to beat Bitcoin down but I agree with you that the project and its community don't sit down and see the storm comes. Bitcoin security model: a deep dive. It's very old insightful article written in 2016. J. Lopp's Post-Quantum Migration BIP. Bitcoin community is huge and has many excellent brains like J. Lopp, who has contributed a lot over years. He returned to forum with that post for discussions and insightful ideas on dealing with Quantum computer threat.

That's true but the jump is the main concern and the fact that quantum + shor's algorithm only increases polynomially in time and energy needed to break stronger encryption compared to classical computer that needs exponential increase is a concern. I'm no expert at this field though, there could be things that should've taken into account. At least nobody got enough qubits yet to do all that.

No one said that quantum is a myth, we have Bitcoin developers for this type of reasons, they are still active for this type of reasons and since I've been in crypto space I have been hearing about quantum threat, it is already a very long time, enough for them to have prepared for this, developers can't update the public about the plans and projects to beat the quantum threat but I expect them to have already have some things figured out compare to projects that come into the spotlight in 2024, Bitcoin is one of the oldest in this space.

And so its fairly safe to say that Bitcoin development is progressing as normal but with a consideration to quantum computing as well. I think Michael Saylor mentioned in the past about quantum computers that they would be better deployed in strengthening the Bitcoin network rather than trying to attack it. Would it be a fair argument that it takes greater computing power to attack the network than to support it?

I read somewhere that it takes 10,000 qubits to hack Bitcoin and 102,000 qubits to hack RSA-2048. I read that in a news article on this forum. I'll share it if I find it. Edit: The discussion was shared in the Turkish section of this forum. https://bitcointalk.org/index.php?topic=5578941.0 Original text to translate english: A research paper by Caltech and the quantum startup Oratomic revealed that the cryptography protecting bitcoin and ether wallets can be broken with just 10,000 physical qubits, far below previous estimates of hundreds of thousands. Based on Google's quantum circuits, the authors state that a neutral atom quantum computer with approximately 26,000 qubits could solve the standard ECC-256, which secures large blockchains, in about 10 days, while RSA-2048 would require approximately 102,000 qubits and three months. https://www.coindesk.com/markets/2026/03/31/quantum-computers-could-break-crypto-wallet-encryption-with-just-10-000-qubits-researchers-say

Looking at the community notes, the method used to break the 15-bit key relied on classical verification and does not demonstrate effective quantum key guessing. To me, it looks like someone broke a 15-bit key using the traditional method that exists for years and just mixed it somehow with quantum. Might just be misinformation.

Türkiye is one of the few countries that have entered the quantum computing race. Prof. Dr. Ali Bozbey has already completed a 5-qubit computer with the QuanT project. The target is now 20, then 100, 1000, 10000 qubit models. I don't know if they're also working on hacking Bitcoin, but I'd like to be there when they test the 10,000 qubit machine. I'm very curious about the moment when Bitcoin is hacked and the private keys are obtained. The easiest way is to crack all 1-256 bit keys that have had at least one transaction made and still have a balance. I think this would require far fewer qubits. The real issue is building a large RAM that will hold a list of all public keys and that the quantum computer can access. Building RAM for quantum machines is apparently very costly and difficult.

Most of all the talk regarding quantum computer and BTC is just fud and nothing more. The media make it seems like the development of quantum computers is solely for one purpose, to break BTC and derive private keys from public keys. We've discussed quantum computers and BTC endlessly in this forum and what indeed would be done if it ever becomes a threat, but every now and then the fud gets louder, probably designed to get bitcoiners worried about the security of their coins.

Of course, a lot of misinformation here. Anything with the word "quantum" in it could be a magnet for financing, so I would expect a little bit of bias from the developer.

It seems the person who cracked this 15-bit key knows nothing about Bitcoin brute-force attacks. I can crack the 70-bit key in the Bitcoin puzzle in 7 minutes using only the CPU. This is already a solved puzzle, and keys of this length can be cracked in minutes if the public key is known. I think it's a very amateur effort, and I haven't been able to crack the 135-bit one yet, but someone will announce it soon. Even if they solve the puzzle now, they can't move the wallet because if there's more than one person who knows the key, the wallet can't be moved. Because they can lock the wallet by setting up a sweeper bot. It's quite understandable that amateurs or professionals working on quantum computers would work on Bitcoin brute-force attacks for their own self-promotion. Given that there are academic studies in this field in at least 15 countries, and hundreds of projects including amateur ones, we can start to worry about this issue when someone completes their research in this area in 5 or 10 years. These reports are not exaggerated; they are the result of a natural process that those interested in this subject have been expecting.

I am also suspecting that the industry is trying to play a vital role with the quantum computer attack on bitcoin. This can be building up something for the next bull run. Your curiosity about less powerful CRQC now having profits also hit me differently. We know that cracking 15-bit is trivial and also BlackHatCoiner pointed that it could be achieved by a classical brut forcing. But it is worth questioning why Project Eleven will award 1 BTC bounty for something that is so trivial? It means quantum played an important role, even if it's minor. I agree that 15 bit is something infinitesimal, but the claim that you can crack a 70-bit key in 7 minutes in CPU is exaggerated. A 70-key is large already ( 2^70 possibilities). This seems beyond what a normal CPU can brute force in a few minutes. If more than one person knows the key, it doesn't prevent spending, rather it will trigger a race situation where the first valid transaction wins. A sweeper bot can only compete for the funds, does it really stop spending?

This was an interesting feat and there is also a lot of misinformation. But I think there is a chance (very very small, but exists) that one day we might face a bad news regarding quantum computers and cryptocurrencies. This might not be bitcoin related. Maybe they will break smartcontracts in Ethereum computers, or fuk up stablecoins, I don't know and I can't predict. But this makes me think about diversifying away from crypto sometimes....

It makes me curios as to if the creators of bitcoin can also improve the security of crypto more so that this problem gets solved .

After you wrote that, I tried again and this time it took 12:32 minutes and 32 seconds. https://github.com/GiladLeef/kangaroo Download this repository and build it on your machine, then go to this address for the found puzzle information: https://privatekeys.pw/puzzles/bitcoin-puzzle-tx?table=0&status=solved Scroll the screen until you see puzzle number 70. Then go into the puzzle directory inside your project directory and then create a new text file by giving the command . Enter the following information into it: Finally, Execute the command and wait a while. It will query many keys in that range and when it finds a conflict with the public address you specified, it will print the private key to the screen. The address of the wallet found; https://mempool.space/tr/address/19YZECXj3SxEZMoUeJ1yiPsw8xANe7M7QR I think when too many people have the private key, they immediately set up sweeper bots, and when there is activity in the wallet they are waiting for, they all enter the race by paying more fees. If these spam expenditures exceed a certain number, I think the miner rejects them all. Only some miners allow such expenditures, and they need to make the expenditure without announcing it to the mempool in order to move the wallet. Some miners also allow this.