OneKey Founder: Some Older iPhones Have Unpatchable Chip Vulnerabilities, Posing Risks to Seed Phrase Storage OneKey founder Yishi warned that factory-resetting an older iPhone, enabling airplane mode, and using it to store crypto wallet seed phrases offline may still be unsafe. He noted that iPhone 4S through iPhone X are affected by checkm8, while iPhone XS, XR, 11 series, and second-generation iPhone SE are affected by usbliter8, disclosed earlier this year. These BootROM-level vulnerabilities cannot be fixed through iOS updates. Attackers with physical access and specialized tools may exploit them via USB, even in airplane mode. However, on models such as the XS and 11, these flaws alone do not provide direct access to seed phrases, as device passcodes and the Secure Enclave offer additional protection. Yishi advised affected users to generate entirely new seed phrases in a trusted environment, transfer their assets, use newer devices, keep software updated, and adopt stronger passwords.