News Quantum Computer Development Could Put Bitcoin Security at Risk by the 2030s


I had a feeling it wouldn't be much longer before someone published a paper about the potential vulnerability of crypto to quantum computing.

Attacking the block chain itself isn't particularly useful since you are competing against the network hash rate for the next block, which means you need a quantum computer powerful enough to achieve a 51% attack to hijack the block chain. The more interesting thing to attack IMO would be wallet encryption. Solve that and then you have all of the time within reason to drain every wallet with sufficient data on the blockchain to factor out the wallet's private key into your own wallets.

TJ Hooker

This article has mixed up a few details. SHA-256 is not a form of encryption, it is a hashing algorithm. When the paper talks about quantum computers one day being able to break Bitcoin's encryption, they're referring to the 256 bit ECC (elliptic curve cryptography) public key cryptography that Bitcoin uses.

It has been well known for many years that current public key cryptography algorithms (ECC and RSA) will be vulnerable to quantum computers. And when that does happen, it'll have a much larger impact than just Bitcoin. Most secure networking relies on public key cryptography. E.g. HTTPS, which uses public key cryptography to verify the identify of the website you're connecting to (via its digital signature) and to establish a secure communication channel. All of these protocols will need to switch over to quantum resistant algorithms prior to quantum computers getting too fast, or we're all going to have a bad time.


If your goal is to simply "break" bitcoin, then you don't even need to crack the cryptography. You just need need to be able to reliably predict which blocks will get a payout.
That's not the only step, but the ensuing arms race would make BTC virtually untradeable within a few months.


Dec 31, 2007
I sure hope that all cryptocurrencies get cracked and become worthless ASAP.
I also hope that news like this is going to push their worth down even right now.
They are the reason behind the huge video card price and availability problems, and that is my only interest in this field.
For all I care, people who are making an income out of this should start working like the rest of us.