[Circle Releases 'Post-Quantum Security Whitepaper,' Proposing a Phased Post-Quantum Resilience Roadmap for the Arc Ecosystem] Foresight News reports that Circle has released the 'Post-Quantum Security Whitepaper,' proposing a phased post-quantum resilience roadmap focused on the long-term security of the Arc blockchain ecosystem. The roadmap covers multiple technical directions, including quantum-secure signatures, private execution environments, validator hardening, infrastructure migration, and account recovery. Its scope applies to core components such as the Arc network, USDC, smart contracts, and validators. The plan aims to provide post-quantum signature support by the time the Arc mainnet goes live (2026).