In order for a quantum-computer to pose danger to Bitcoin it would require to have between 100000 - 1million logical qubits!
https://eprint.iacr.org/2021/967.pdf shows that 2330 logical qubits suffice.
My bad, you're right. They are physical qubits.
Breaking Bitcoin's ECDSA requires ~2,300+ logical qubits (or millions of physical qubits), placing practical attacks decades away.
Requirement to break ECDSA:
Logical Qubits:
~2,330–2,619Physical Qubits (1-hour):
317 millionPhysical Qubits (1-day):
13 millionCointelegraph's
recent article wrongly states the following:
Did you know? Hardware studies suggest that breaking a Bitcoin wallet’s ECDSA key within one hour would (optimistically) require around 13 million logical qubits (or more than 300 million physical qubits, depending on error correction regimes).
Regardless, today and in the next few decades (min 10, max 20 years) there will be
no danger to Bitcoin. Anyone who pushing for "quantum-resistant" Bitcoin today is only cares about selling you "super secure Bitcoin wallets" so they can grab your Bitcoins. Not kidding. See for example this:
https://bitcointalk.org/index.php?topic=5550298.msg65666459#msg65666459 Corporations who selling Bitcoin wallets are pushing to ban all non-quantum transactions in Bitcoin in the "next 5 years". Be aware!