Odaily Planet Daily reports: OneKey founder Yishi posted on X platform, "How to Turn an iPhone into a Cold Wallet."
Yishi said: “It is recommended to use an iPhone 17 or newer model, running iOS 27 or later, and replace the device every one to two years... I would not use an iPhone 16 or any older model for long-term signing of important asset transactions. Even an iPhone 17 with iOS 27 represents only the minimum configuration I currently accept. For long-term custody of significant funds, I prefer dedicated signing devices with transparent security design, ongoing maintenance, and on-device transaction verification. Their firmware, supply chain, and recovery processes still require further review; keeping the phone offline is a precautionary measure. However, the actual effectiveness of this precaution depends on factors such as hardware integrity, patch level, BFU/AFU status, passcodes, and wallet key management.”