Hi, Secure Boot on arm64 should be working fine with grub2 2.06-9 or later and shim-signed 1.39, both in sid. If you have SB-capable hardware please give it a try. It should just be a matter of ensuring that your grub-efi-arm64-signed and shim-signed packages are up-to-date. For details about enabling Secure Boot and more information see https://wiki.debian.org/SecureBoot Thanks, ema