Quantum computers are a million times too small to hack bitcoin

3 months ago

Bitcoin is theoretically susceptible to being cracked by quantum computers, but calculations amusement they would request to beryllium a cardinal times larger than those that beryllium today

Technology 25 January 2022

By Matthew Sparkes

Bitcoin graphic

Bitcoin could 1 time beryllium threatened by quantum computers – but not yet

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Quantum computers would request to go astir a cardinal times larger than they are contiguous successful bid to interruption the algorithm that secures bitcoin, which would enactment the cryptocurrency astatine hazard from hackers.

The bitcoin web is kept unafraid by computers known arsenic miners that usage a cryptographic algorithm called SHA-256, which was created by the US National Security Agency. Breaking this codification is fundamentally intolerable for mean computers, but quantum computers, which tin exploit the properties of quantum physics to velocity up immoderate calculations, could theoretically ace it open.

Now Mark Webber astatine the University of Sussex, UK, and his colleagues person investigated however ample a quantum machine you would request to interruption bitcoin, successful presumption of the fig of qubits, oregon quantum bits, the equivalent of mean computing bits.

Every bitcoin transaction indispensable beryllium “confirmed” by the web of miners earlier it is added to the blockchain, the immutable ledger of who owns what. Each transaction is assigned a cryptographic cardinal during this confirmation process, and cracking the cardinal would let you to instrumentality ownership of those bitcoins.

“The transactions get announced and there’s a cardinal associated with that transaction,” says Webber. “And there’s a finite model of clip that that cardinal is susceptible and that varies, but it’s usually astir 10 minutes to an hour, possibly a day.”

Webber’s squad calculated that breaking bitcoin’s encryption successful a 10-minute model would necessitate a quantum machine with 1.9 cardinal qubits, portion cracking it successful an hr would necessitate a instrumentality with 317 cardinal qubits. Even allowing for a full day, this fig lone drops to 13 cardinal qubits.

This is reassuring quality for bitcoin owners due to the fact that existent machines person lone a tiny fraction of this – IBM’s record-breaking superconducting quantum machine has lone 127 qubits, truthful devices would request to go a cardinal times larger to endanger the cryptocurrency, thing Webber says is improbable to hap for a decade.

Although bitcoin is unafraid for the foreseeable future, determination are concerns astir different encrypted information with a overmuch wider model of vulnerability. An encrypted email sent contiguous tin beryllium harvested, stored and decrypted successful the aboriginal erstwhile a quantum machine is disposable – a alleged “harvest now, decrypt later” attack, which some information experts judge is already happening.

“People are already disquieted due to the fact that you tin prevention encrypted messages close present and decrypt them successful the future,” says Webber. “So there’s a large interest we request to urgently alteration our encryption techniques, due to the fact that successful the future, they’re not secure.”

Journal reference: AVS Quantum Science, DOI: 10.1116/5.0073075

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