(CryptoNews) Quantum computing has long been regarded as Bitcoin (BTC)’s ‘bogeyman.’
One other popular assumption is that, because they don’t use PoW, proof-of-stake cryptoassets such as Cardano (ADA), Polkadot (DOT), and Tron (TRX) (and eventually, Ethereum (ETH)) aren’t as vulnerable to quantum computing attacks as networks like Bitcoin, Bitcoin Cash (BCH) and Litecoin (LTC). However, according to a variety of computer scientists and crypto experts, it’s not the consensus mechanism of a coin which creates the biggest risk in terms of quantum computers, but rather the signature system.
The important point to make when considering whether PoS is less vulnerable to quantum computing is that there are two mechanisms by which a quantum computer might violate a cryptoasset:
The mechanism used to win the right to publish a block of transactions and to achieve distributed consensus (e.g. PoW or PoS)
The mechanism used to authorize individual transactions (typically involving some public/private key signature system)
While Bitcoin’s weakness compared to PoS cryptoassets is still pretty hypothetical, quantum computing poses another threat that concerns PoS and PoW in equal measure.
“Even if consensus requires no cryptographic ‘work’ [in the case of PoS] it still does rely on cryptography which is currently mainly based on elliptic curves which are vulnerable to quantum algorithms. An attacker with sufficiently powerful quantum computers could break other validators signatures and still mess with the consensus,” said Marek Narożniak — a physics PhD student at New York University who has worked with Prof. Tim Byrne on research into quantum computing.
In an analysis published by Deloitte, Bram Bosch wrote that around four million bitcoins are stored in addresses that use p2pk and p2pkh scripting, which is vulnerable to attacks via quantum computers. “Presently, about 25% of bitcoins in circulation are vulnerable to a quantum attack. Even in case one’s own bitcoins are safe, one might still be impacted if other people will not (or cannot) take the same protection measures.”
Fortunately, current cryptographic research is more than aware of the theoretical threat posed by quantum computing, so you probably shouldn’t start selling all of your crypto just yet.
Researchers at Imperial College London published a paper in 2019 that outlined a protocol that would allow Bitcoin “users to securely move their funds from non-quantum-resistant outputs to those adhering to a quantum-resistant digital signature scheme.”
What’s interesting about the danger posed by quantum computing: it’s unknown, unpredictable quality. But given that it’s a risk mostly to the signatures used by pretty much all cryptoassets, we do know it will be a threat to PoS and PoW cryptos alike.