I made a few more tests taking into account what Prof. Rickert posted above. I recovered the files from 13.2 and used a different mix of them to boot my system with secure boot enabled: The files for 42.1 are the ones from the Leap installation in my system. The files for 13.2 are: -shim.efi and MokManager.efi from http://download.opensuse.org/repositories/openSUSE:/13.2/standard/x86_64/shim-0.7.318.81ee561d-3.4.1.x86_64.rpm -grub.efi from http://download.opensuse.org/distribution/13.2/repo/oss/suse/x86_64/grub2-x86_64-efi-2.02~beta2-20.5.1.x86_64.rpm shim.efi | grub.efi | MokManager.efi | Boot with secure boot ---------+----------+----------------+---------------------- 42.1 | 42.1 | 42.1 | Fail ---------+----------+----------------+---------------------- 13.2 | 13.2 | 13.2 | OK ---------+----------+----------------+---------------------- 42.1 | 13.2 | 13.2 | OK ---------+----------+----------------+---------------------- 42.1 | 13.2 | 42.1 | OK ---------+----------+----------------+---------------------- So I suppose the problem could be in the grub.efi file from 42.1.