No, new quantum claims by Google don’t mean it’s 20 times easier to crack Bitcoin

A new paper from a Google quantum researcher has once again raised alarms that bitcoin’s (BTC’s) cryptography might be under a greater threat than previously thought. However, in short, once again, rumors about an imminent quantum attack on bitcoin are exaggerated.

In his most recent paper, Craig Gidney, Quantum Research Scientist at Google, said that 2048-bit Rivest–Shamir–Adleman (RSA) encryption could theoretically be broken by a quantum computer with 1 million noisy qubits running for one week. This is 20 times fewer than the number he estimated in 2019, when the estimate had already been lowered from 1 billion physical qubits. A qubit is the basic unit of information in quantum computing, while the terms noisy and physical describe qubit quality – noisy referring to non-ideal, error-prone qubits.

According to Gidney, this reduction in required qubit count comes from two sources: improved algorithms and better error correction.

The news was quickly picked up by the crypto industry, with some claiming the research shows that bitcoin encryption can be broken 20 times more easily than previously believed.

However, the key point here is that bitcoin doesn’t use RSA – its security depends on elliptic curve cryptography (ECC). That said, this doesn’t mean the quantum computer threat to bitcoin doesn’t exist, or that one day such machines couldn’t steal BTC by deriving private keys from public keys. A public key, which is used to receive bitcoin, is derived from a private key, which grants access to your BTC, so a quantum computer would need to reverse-engineer it.

In a report on bitcoin and quantum computing released today by Chaincode Labs, a research and development group focused on bitcoin and related technologies, it’s estimated that cryptographically relevant quantum computers (CRQCs) could potentially enable the theft of around 6.26 million BTC ($682 billion), destabilizing the entire ecosystem.

As this potential threat is known, bitcoin developers are working on the network’s quantum readiness.

"However, all of these initiatives, including those with publicly visible components, remain at an early and exploratory stage, with much of the preliminary research still occurring informally and privately," Chaincode Labs said, reminding readers of expert and government estimates that CRQCs could arrive within the next decade.

The researchers suggest implementing a dual-track strategy: first, within approximately two years, develop contingency measures that can be quickly deployed if needed, while simultaneously pursuing a more comprehensive, roughly seven-year path toward optimal quantum resistance.