Quantum computing is Bitcoin’s boogeyman. It’s theoretically possible that technology could evolve so far that hackers could break Bitcoin’s cryptographic algorithm, steal private keys, and ultimately crash its price.
But researchers reckon today’s quantum computing power is still millions of times too weak to hack Bitcoin, reports New Scientist.
Quantum computers run on qubits, a kind of computing power that exploits the laws of physics at the subatomic scale (more on that later).
A team of researchers at the University of Sussex have worked out how many qubits a quantum computer would need to brute force Bitcoin’s 256-bit private key hashes.
Lead brain Mark Webber found that a quantum computer requires:
- 1.9 billion qubits to crack Bitcoin in 10 minutes.
- 317 million qubits to crack Bitcoin in an hour.
- 13 million qubits to crack Bitcoin in a whole day.
Webber’s calculations far exceed the measly 4,000 qubits reported under headlines like Decrypt’s “Quantum computers could crack Bitcoin by 2022,” published in 2020.
The IBM Eagle — the most powerful quantum computer in the world right now — boasts just 127 qubits.
Today’s quantum computers won’t hack Bitcoin (while you’re still alive)
While IBM Eagle is several billions of times more powerful than a standard computer, quantums would still need at maximum 10.79 quintillion years to crack Bitcoin’s encryption (785 million times the age of the known universe).
Still, a quantum computer is nothing like the machine that sits on your desk.
Quantum computers manipulate a sub-atomic physical state called the “superposition,” where a particle exists in several places at once until it’s observed.
These machines operate at near absolute zero (almost −460 degrees Fahrenheit), allowing them to work outside of the binary ones and zeroes found in a traditional laptop or PC.
This means quantum computers can perform several tasks simultaneously; they’re much better at crunching numbers like the ones powering Bitcoin’s hashing algorithm (SHA-256 developed by the US National Security Agency).
Bitcoin might be currently safe from the quirky laws of quantum physics, but other encrypted data could be up for grabs.
Save now, hack later
Security experts warn that encrypted data (like emails) sent now might be lying dormant on a bad actor’s hard drive while they wait for quantum computing to catch up.
“People are already worried because you can save encrypted messages right now and decrypt them in the future,” said Webber (via New Scientist).
“So, there’s a big concern we need to urgently change our encryption techniques because, in the future, they’re not secure.”
But current quantum computing power is still way off. IBM said they plan to have a quantum computer with over 1,000 qubits by next year — far fewer than the 13 million qubits Webber and his team believe would be required to hack Bitcoin in one day.
Webber told reporters he believed that quantum computers could catch up in about a decade.
Bitcoin could future-proof itself by hard forking to adopt quantum-secure encryption, Webber and his team said, which researchers around the world have been working on perfecting for the past 20 years.
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