In the "Authentication File" slot of SP Flash Tool, browse and select the .auth file.
: Officially, these files are intended for OEM service representatives to unbrick devices. mt6785 auth file
: During boot-up, the device's processor reads the auth file and uses the public key to verify the digital signatures of the software components. If the signatures are valid and match, the device proceeds to boot. If not, the boot process is halted to prevent potentially malicious software from running. In the "Authentication File" slot of SP Flash