Circle has announced a quantum-resistant roadmap for its Layer 1 blockchain, Arc, outlining a phased approach to achieving full-stack quantum resistance. This initiative will cover wallets, private state, validators, and infrastructure. The mainnet will feature post-quantum signatures available through an opt-in model. Circle highlighted the potential threat of quantum computing to public-key cryptography by 2030 or sooner, cautioning against "harvest now, decrypt later" risks.