Quantum Computers Could Break Modern Encryption Once They Reach Fault-Tolerant Scale

An article on DEV Community warns that a 'Q-Day' is approaching, when fault-tolerant quantum computers become powerful enough to run Shor's algorithm and undermine today's public-key cryptography. It explains that RSA and elliptic-curve schemes rely on problems that are hard for classical machines, but that roughly 4,096 fault-tolerant logical qubits could cut the time needed to break RSA-2048 or ECC-256 from thousands of years to under eight hours. The piece argues that blockchains, TLS and web certificate systems would be exposed, and that adversaries are already storing encrypted traffic to decrypt later. It recommends migrating to NIST-approved post-quantum standards such as ML-KEM, ML-DSA and lattice-based cryptography before the transition window closes.