Crypto Preps for Looming Q-Day Predicted by Google Coinbase CEO Brian Armstrong said last week in response to Google’s paper that “we all need to solve it sooner rather than later.” Sign up for smart news, insights, and analysis on the biggest financial stories of the day. On the upside, advanced quantum computers could crack that 12-word seed phrase from 2013 that was scribbled on a piece of paper your mom threw out. But that level of encrypting ability can also unravel cryptocurrency’s core security … womp womp. Q-Day is the Y2K-esque time when quantum computers become advanced enough to decode all cryptography. Google recently warned it could be coming for cryptocurrency before the decade’s out. In a new paper, researchers wrote that quantum computers would need fewer than 500,000 physical qubits to break through bitcoin and other cryptocurrencies — 20 times fewer than previous estimates. Google researchers noted that 6.9 million public bitcoin keys are already exposed, leaving them wide open for quantum computers to crack at their leisure. There’s also a ~10-minute window when public keys are exposed during transactions, and the researchers said advanced quantum computers will be able to wheedle out a private key from a public one in nine to 12 minutes. Quantum Safety 101 Google is pushing companies to transition to post-quantum cryptography, which uses algorithms that quantum computers can’t easily crack. In PQC, a quantum computer may have to try to solve for, for instance, a vector in a thousand-dimensional lattice. Developers are debating how to push crypto toward quantum-proof practices: - The Bitcoin Improvement Proposal (BIP)-360 aims to provide a way for bitcoin owners with older wallets to opt in to move their holdings to safer addresses. Another idea, the Hourglass proposal, would restrict how quickly older coins can be spent to