iPhone cold w2026-10-14 07:44:34Yishi says an offline iPhone should start at iPhone 17 and iOS 27 to serve as a cold walletOneKey maintainer Yishi laid out a strict baseline for anyone who wants to turn an iPhone into an offline signing device for crypto storage. His minimum standard is an iPhone 17 or newer, running iOS 27 or later, with a migration plan to newer hardware every one to two years. The article argues that taking a phone offline does not remove the risk created by physical access. Instead, the real security picture depends on hardware generation, patch level, whether the device is in BFU or AFU state, the strength of the device passcode, and how the wallet itself handles key material. The piece walks through border searches, mobile forensics vendors, USB attack surfaces, the difference between chip-off access and decryption, and the limits of Secure Enclave-based protection for wallet secrets. It also explains why storing a seed phrase in Notes or Photos is still a direct exposure, even if the phone is offline. Yishi’s broader point is that an offline phone can be one precaution, but it is not a complete custody model on its own. He closes with a practical setup: a dedicated device initialized from a trusted state, a random 12-character-or-longer alphanumeric passcode, independent offline recovery backups, minimal interfaces enabled, and a wallet whose encryption, authorization flow, and key handling can be examined in detail.90
OneKey2026-10-14 03:12:32OneKey founder says iPhones can serve as cold wallets, but only from iPhone 17 onwardOneKey founder Yishi said in a post on X that an iPhone can be used as a cold wallet, but he only recommends doing so with an iPhone 17 or newer running iOS 27 or later. He added that the device should be replaced every one to two years. Yishi said he would not use an iPhone 16 or any earlier model as a long-term signing device for important asset transactions, and that even an iPhone 17 with iOS 27 is only the minimum setup he currently considers acceptable. For long-term storage of large amounts of funds, he said he prefers a dedicated signing device with a transparent security design, ongoing maintenance, and on-device transaction verification. He also said the firmware, supply chain, and recovery process of such devices still require more review. In his view, taking a phone offline is only a precaution, while the actual effectiveness of that precaution depends on factors including hardware, patch level, BFU/AFU state, passwords, and wallet key management.100
