Cryptocurrency networks rely heavily on cryptography to protect wallets, authorize transactions and maintain blockchain integrity. Quantum computing introduces a long-term security challenge as sufficiently powerful quantum computers could solve mathematical problems that conventional computers cannot efficiently handle.

Bitcoin, Ethereum and many other cryptocurrencies use public-key cryptography to prove that transactions were authorized by legitimate asset owners. Bitcoin and standard Ethereum accounts, for example, use elliptic-curve-based digital signatures.

A sufficiently capable fault-tolerant quantum computer running Shor’s algorithm could theoretically derive private keys from exposed public keys. An attacker could then potentially generate unauthorized signatures and spend cryptocurrency controlled by affected keys.

Despite possible risks, the immediate threat is yet to arise. Current quantum computers do not have access to the necessary logical qubits needed to carry out large-scale attacks on cryptocurrencies’ elliptic-curve cryptography. 

The latest quantum-resistant roadmap provided by Ethereum states that research done by Google Quantum AI in March 2026 estimates that around 1,200 logical qubits would be needed to attack 256-bit elliptic-curve cryptography. Current computers remain far from that capability, as obtaining a reliable logical qubit requires far more than thousands of physical qubits.

Governments and technology organizations are preparing well before quantum attacks become practical. The US National Institute of Standards and Technology finalized its first three post-quantum cryptography standards in August 2024: FIPS 203 for ML-KEM, FIPS 204 for ML-DSA and FIPS 205 for SLH-DSA.

NIST selected HQC in 2025 as an additional key-encapsulation algorithm based on different mathematics from ML-KEM. Meanwhile, in May 2026, NIST published its second-round report evaluating additional digital-signature algorithms for possible standardization.

Source link