CompTIA Linux+ XK0-006 (V8) Practice Question

The Argon2 KDF used by LUKS2 supports three cost parameters: iterations (time), memory, and parallelism (threads). The cryptsetup option that directly controls the memory cost is --pbkdf-memory <number>, where the value (in kibibytes) sets the maximum amount of RAM Argon2 will reserve during key stretching. Increasing this value makes each password-guess more expensive in GPU/ASIC attacks.

--pbkdf-parallel changes thread count, not memory; increasing it without more RAM does little to slow brute-force searches. --pbkdf-force-iterations overrides the time-cost only and has no effect on memory usage. --keyslot-cipher selects the cipher used to encrypt keyslots and is unrelated to KDF parameters.