Secureboot
What is Secure Boot?
This is a security feature to protect against malicious unauthorized software at boot. Microsoft Windows used to make sure the version of Windows that os booted has not been tampered.
How does Secure Boot works?
It uses asymetric cryptografy to validate the signature of the operating system. The operating system is signed using the private key. The publoc key is stored in the UEFI is used to validate against the signature. If the validation fail, the boot is interrupted.
Configuring Secure Boot
You have to create your own certificate to enroll into secure boot. This will allow signing UEFI application.