Or sometimes with a metadata line:
It sounds like you're referring to the used for PlayStation 3 (PS3) disc decryption, often in the context of backup loading , emulation (RPCS3) , or CFW (Custom Firmware) . ps3 disc key file
D3B07A5F2E1C8A4F6B9C2D3E5F7A8B1C (some tools expect it uppercase, others lowercase; no spaces) Or sometimes with a metadata line: It sounds