How to create a LUKS partition encrypted with Adiantum, ideal for low end and older devices/computers

adiantum-encryption-how-to.md

How to create a LUKS partition encrypted with the Adiantum scheme

Important note

• Sector size and key size are fixed, you cannot change them!
• You can play with the hash but using less than sha256 is irresponsible!
• You can convert an already existing luks2 partition with cryptsetup(8).

Very low end devices or computers (say, an old Pentium, Celeron, Raspberry Pi or older SoC)

cryptsetup luksFormat --type luks2 \
--sector-size 4096 \
--cipher xchacha12,aes-adiantum-plain64 \
--hash sha256 --key-size 256 <device>

cryptsetup reencrypt \
--sector-size=4096 \
--cipher xchacha12,aes-adiantum-plain64 \
--hash sha256 --key-size 256 <device>

Low end devices or computers (say, a Core 2 Duo, a smartphone post 2016)

cryptsetup luksFormat --type luks2 \
--sector-size 4096 \
--cipher xchacha20,aes-adiantum-plain64 \
--hash sha256 --key-size 256 <device>

cryptsetup reencrypt \
--sector-size=4096 \
--cipher xchacha20,aes-adiantum-plain64 \
--hash sha256 --key-size 256 <device>

No need to differentiate as xchacha12 is (for now) known to be as safe, has plenty of margins. Might as well be faster.