Yishi: It is recommended to only use iPhone 17 and later models as cold wallets

OneKey founder Yishi suggests using iPhone 17 or newer models and iOS 27 or higher as a cold wallet, and changing devices every one to two years. Yishi will not use iPhone 16 or earlier models to sign important asset transactions. For long-term custody of large funds, Yishi tends to use dedicated signature devices with transparent and secure design, sustainable maintenance, and transaction verification.