Quantum computing's hidden figure: the engineer chasing the algorithm that could end encryption
Craig Gidney, a researcher at Google Quantum AI, is working on quantum circuits that could run Shor's algorithm, a procedure capable of breaking common encryption. His work is largely unknown outside quantum computing circles, but if successful, it could usher in powerful quantum computers while simultaneously undermining digital security. The potential event, known as Q-Day, would expose emails and bank accounts to decryption.
Gidney's research focuses on shrinking the resource requirements for Shor's algorithm, which would allow it to run on quantum machines with fewer qubits than previously thought necessary. His technical blog and co-authored papers have become reference points within the quantum computing community, even as he avoids public visibility. The algorithm itself targets two mathematical foundations of modern encryption: large-number factoring and elliptic curves, both of which conventional computers cannot solve efficiently.
The timeline for Q-Day hinges on hardware progress. Quantum computers currently operate with far fewer than the millions of qubits once considered mandatory for breaking encryption, but recent advances across multiple research teams have narrowed that gap. Gidney's circuit optimizations represent one of the few concrete paths toward making the threat practical rather than theoretical.
If Q-Day arrives, the impact could be sweeping: encrypted emails, financial transactions, and stored data would become vulnerable to decryption by anyone with access to a sufficiently powerful quantum machine. Governments, corporations, and individuals alike may face a sudden erosion of digital trust, forcing rapid migration to post-quantum cryptographic standards. The timeline remains uncertain, but the possibility alone could pressure institutions to accelerate security overhauls, while also raising questions about who controls such computational power and how its use might be governed.