Introduction

Normally, enabling OEM unlocking in Developer options lets you request a bootloader unlock using fastboot.

On the Light Phone III, there is another check: the bootloader also expects manufacturer authorisation.

That extra check has a flaw. It accepts a signed unlock file without properly checking who issued the certificate used to sign it. We can create a file specifically for your phone that passes the check.

This guide uses Prism for temporary root access to place that file on the phone. After restarting into fastboot, you can use the normal unlock command and confirm on the phone.

You can find Prism at vandamd/prism and this website at vandamd/light-guide.