Wu Shuo learned that Arc's official statement said that Circle released a post-quantum security white paper, proposing a phased security roadmap for Arc, USDC, smart contracts, validators, and infrastructure systems. The white paper states that quantum computing could pose long-term risks to blockchain signatures, validator keys, smart contracts, and network communication. Circle plans to support SLH-DSA signature verification in Arc and allow USDC smart contracts to continue supporting ECDSA interactions during the transition period, while enabling post-quantum signatures. Circle indicated that the final switch timing will depend on ecosystem readiness, regulatory requirements, and quantum risk assessments, and the related roadmap may still be adjusted.