Here’s a helpful write‑up for prod.key in the context of (likely for a checkm8/vulnerability research or jailbreak perspective). What is prod.key ? prod.key is a plaintext file used by img4 , img4tool , and other bootchain decryption tools (like those from the libimobiledevice or iOS-odec ecosystem). It stores key , iv (initialization vector), and sometimes tag for decrypting a specific firmware component (e.g., kernelcache , iBEC , iBSS , RestoreRamDisk ).