Q-day:
Google’s new Quantum Echoes experiment using the 65-qubit Willow processor has sparked global debate on whether it accelerates the arrival of Q-day.
- Q-day refers to the moment when a cryptographically relevant quantum computer becomes powerful enough to break widely used encryption systems such as RSA-2048, threatening global digital security.
- The fear stems from Shor’s algorithm (1994), which showed that a sufficiently large quantum computer could factor large numbers exponentially faster, breaking the mathematics behind today’s public-key cryptography.
- Key Features of Q-Day Risk:
- Breaks RSA & ECC: Quantum computers could factor keys and compromise global internet security.
- Harvest Now, Decrypt Later: Hackers/governments may store encrypted data today and decrypt it later.
- Requires millions of logical qubits: Current machines have only hundreds of noisy qubits — far from attack capability.
- Triggers Post-Quantum Cryptography (PQC): Push for quantum-safe algorithms like CRYSTALS-Kyber & Dilithium (standardised by NIST).
