Btrfs doesn’t have encryption, so you need to do it with luks to an mdadm raid, and build btrfs on top of that. Luks on mdadm raid is known to be slow, and in general not a great idea.
Why involve mdadm? You can use one btrfs filesystem on a pair of luks volumes with btrfs’s “raid1” (or dup) profile. Both volumes can decrypt with the same key.
A related issue I still see very often, even with files newly created just this year, is when trying to extract zip files on my Linux systems that contain non-ASCII filenames and that were created on Windows systems, especially ones with apparently non-English locales like Japanese. Need to trial and error the locale I give to unzip and sometimes hack together fixed names with iconv until the mojibake seems to fix itself.