As quantum ‘Q-Day’ jumps to 2029, Ethereum faces a new fight over what to do with coins left in old wallets

The crypto industry has framed its quantum reckoning as a single catastrophic “Q-Day” moment when a sufficiently powerful machine arrives, old cryptographic keys shatter, and blockchain history unravels. This week, that moment may have been brought forward into this decade. The Ethereum Foundation’s Mar. 24 post-quantum (PQ) roadmap shows that the realistic quantum threat to Ethereum centers on forged sig…