Tumbleweed with LUKS2 and Argon2

The steps below show you how to install openSUSE Tumbleweed with LUKS2 and Argon2id as Password-Based Key Derivation Function (PBKDF) when using systemd-boot¹ instead of GRUB2 as bootloader.

1. Perform an installation with full disk encryption

2. Select Guided Setup during partitioning the disk and use LVM

3. Change the bootloader by selecting ‘Booting’ at the top ot the summary screen

4. Select Systemd Boot as bootloader

5. After the installation is finished, boot into the rescue system of the installation medium. The LUKS conversion cannot be done while the device is in use.

6. Login as root

7. Convert LUKS1 to LUKS2 with:

   cryptsetup convert --type luks2 /dev/sdaX
   

8. Check the result with:

   $ cryptsetup luksDump /dev/sdaX
   
   LUKS header information
   Version:        2
   Epoch:          4
   Metadata area:  16384 [bytes]
   Keyslots area:  2064384 [bytes]
   UUID:           XXXXXXXXXXXXXXXXXXXXX
   Label:          (no label)
   Subsystem:      (no subsystem)
   Flags:          (no flags)
   
   Data segments:
   0: crypt
           offset: 2097152 [bytes]
           length: (whole device)
           cipher: aes-xts-plain64
           sector: 512 [bytes]
   
   Keyslots:
   0: luks2
           Key:        512 bits
           Priority:   normal
           Cipher:     aes-xts-plain64
           Cipher key: 512 bits
           PBKDF:      PBKDF2
           Time cost:  7
           Memory:     1048576
           Threads:    4
           Salt:       XXXXXXXXXXXXXXXXXX
           AF stripes: 4000
           AF hash:    sha256
           Area offset:290816 [bytes]
           Area length:258048 [bytes]
           Digest ID:  0
   Tokens:
   Digests:
   0: pbkdf2
           Hash:       sha256
           Iterations: 129774
           Salt:       XXXXXXXXXXXXXXXXXX
           Digest:     XXXXXXXXXXXXXXXXXX
   

9. Change the PBKDF:

   cryptsetup luksConvertKey --pbkdf argon2id /dev/sdaX
   

10. Check the result again with:

    $ cryptsetup luksDump /dev/sdaX
    
    LUKS header information
    Version:        2
    Epoch:          4
    Metadata area:  16384 [bytes]
    Keyslots area:  2064384 [bytes]
    UUID:           XXXXXXXXXXXXXXXXXXXXX
    Label:          (no label)
    Subsystem:      (no subsystem)
    Flags:          (no flags)
    
    Data segments:
    0: crypt
            offset: 2097152 [bytes]
            length: (whole device)
            cipher: aes-xts-plain64
            sector: 512 [bytes]
    
    Keyslots:
    0: luks2
            Key:        512 bits
            Priority:   normal
            Cipher:     aes-xts-plain64
            Cipher key: 512 bits
            PBKDF:      argon2id
            Time cost:  7
            Memory:     1048576
            Threads:    4
            Salt:       XXXXXXXXXXXXXXXXXX
            AF stripes: 4000
            AF hash:    sha256
            Area offset:290816 [bytes]
            Area length:258048 [bytes]
            Digest ID:  0
    Tokens:
    Digests:
    0: pbkdf2
            Hash:       sha256
            Iterations: 129774
            Salt:       XXXXXXXXXXXXXXXXXX
            Digest:     XXXXXXXXXXXXXXXXXX
    

11. Reboot into your system

Regarding the used cipher, you can benchmark the available ones with

$ cryptsetup benchmark

# Tests are approximate using memory only (no storage IO).
PBKDF2-sha1      1528536 iterations per second for 256-bit key
PBKDF2-sha256    2092966 iterations per second for 256-bit key
PBKDF2-sha512    1546572 iterations per second for 256-bit key
PBKDF2-ripemd160  897753 iterations per second for 256-bit key
PBKDF2-whirlpool  691672 iterations per second for 256-bit key
argon2i       7 iterations, 1048576 memory, 4 parallel threads (CPUs) for 256-bit key (requested 2000 ms time)
argon2id      7 iterations, 1048576 memory, 4 parallel threads (CPUs) for 256-bit key (requested 2000 ms time)
#     Algorithm |       Key |      Encryption |      Decryption
        aes-cbc        128b      1282.2 MiB/s      3857.8 MiB/s
    serpent-cbc        128b       104.2 MiB/s       820.8 MiB/s
    twofish-cbc        128b       242.6 MiB/s       435.4 MiB/s
        aes-cbc        256b       962.9 MiB/s      3095.0 MiB/s
    serpent-cbc        256b       107.9 MiB/s       819.7 MiB/s
    twofish-cbc        256b       248.5 MiB/s       426.4 MiB/s
        aes-xts        256b      3825.8 MiB/s      3821.4 MiB/s
    serpent-xts        256b       715.6 MiB/s       723.8 MiB/s
    twofish-xts        256b       388.7 MiB/s       390.9 MiB/s
        aes-xts        512b      3086.5 MiB/s      3083.5 MiB/s
    serpent-xts        512b       710.5 MiB/s       710.8 MiB/s
    twofish-xts        512b       384.4 MiB/s       385.9 MiB/s

and decide if you want a different cipher instead of aes-xts-plain64. The results above represent an Intel i7-8665U.