Quantum computing threatens elliptic curve cryptography; urges post-quantum security

Unchained podcast guest Alex Pruden (Aleo) warns that quantum computing could soon become cryptographically relevant and endanger elliptic curve cryptography (ECC), a core building block for blockchain security. Pruden says the quantum timeline is accelerating. He cites research showing the qubit requirements for error-corrected quantum computers may drop dramatically—from around a billion qubits to as few as ~10,000 using new error-correction approaches. He also notes estimates ranging into the hundreds of thousands of physical qubits, which implies earlier progress than previously expected. A key risk for traders is that sufficiently capable quantum machines could threaten ECC and, by extension, the security assumptions behind many digital assets. Pruden argues that the probability of quantum impacting cryptography by the end of this decade is “significant,” and a utility-scale system by decade-end is plausible, though not guaranteed. He also stresses that fault-tolerant quantum systems are complex and will not arrive instantly, but the “post-quantum security” transition needs urgency. The outlook diverges: physics researchers appear more optimistic, while cryptography specialists remain cautious—highlighting the need for faster collaboration and migration to post-quantum security. Keywords: quantum computing, elliptic curve cryptography, post-quantum security, qubits, fault-tolerant quantum.