Secure boot back on?

Question

After completing a dual boot, can I turn secure boot back on? Or do I have to keep it off for the entirety of the time I have the dual boot on my system?

Answer 1

Without discussing the merits of secure boot, IMO the advice to disable secure boot is poor. More likely than not you can keep secure boot enabled.

If you use 3rd party unsigned kernel modules you would either need to sign them yourself or disable secure boot. Examples would be ndivia or ATI graphics drivers, wireless drivers, and perhpas virtualbox.

To self sign modules see

https://computerlinguist.org/make-dkms-sign-kernel-modules-for-secure-boot-on-ubuntu-1604.html

How to sign kernel modules with sign-file?

https://insights.ubuntu.com/2017/08/11/how-to-sign-things-for-secure-boot/

https://wiki.ubuntu.com/SecurityTeam/SecureBoot

https://www.kernel.org/doc/html/v4.10/admin-guide/module-signing.html

Although IMO it is easy to sign modules, most people (erroneously) advise you disable secure boot. See first link to automate - https://computerlinguist.org/make-dkms-sign-kernel-modules-for-secure-boot-on-ubuntu-1604.html