Building on 2026 qubit reductions like Iceberg Quantum's qLDPC breakthrough, recent studies project quantum computers cracking RSA-2048 and ECDLP-256 by 2029. Google and cybersecurity experts warn of imminent Q-Day, pushing post-quantum cryptography to avert a crisis worse than Y2K, with businesses ramping up quantum-safe migrations.
Recent studies since early 2026, including algorithmic advances slashing qubit needs to ~100,000 for RSA (as detailed in prior coverage), now forecast practical quantum attacks on RSA-2048 and ECDLP-256 by 2029. A Google team and cybersecurity firms highlight accelerating progress in quantum hardware tackling problems intractable for classical computers.
Q-Day—the arrival of cryptographically relevant quantum computers—looms without fanfare, unlike Y2K. HSBC's Philip Intallura urges: “Experimental timelines can move faster than expected... The institutions that start now will be in a very different position.” Cisco's Ramana Kompella adds: “The time to prepare... is today. In fact, it may have even been yesterday.”
Unique threats include “harvest now, decrypt later” attacks, storing today's encrypted data for future decryption. QuSecure's Rebecca Krauthammer warns of risks to national security, banking, healthcare, and pharma—stolen cards, medical records, or weapons data. Inquiries have surged tenfold recently; a 2029 post-quantum switch is ambitious but feasible.
Early adopters like Signal and Flo apps employ post-quantum methods; Google Chrome aims for safety by 2027. Challenges persist for legacy systems in hospitals and infrastructure. Cryptocurrencies like Bitcoin face hurdles from decentralized consensus, with wallet thefts as potential early Q-Day signals.
