They can test a hill cipher so that when given a hill cipher matrix they can ask find the inverse key of the matrix or given 4 plaintext crib find the keyI was reading the rules to make sure I wasn't wasting to much time reading about the state/nats ciphers, and noticed that for the hill cipher it states, "Mathematical Cryptanalysis of the Hill Cipher - either producing a decryption matrix given a 2x2 encryption matrix or computing a decryption matrix given 4 plaintext-ciphertext letter pairs." What does this rule even mean.
So like they can asks find the inverse of
or something like that (usually in order to then decode something)
Or they can ask something like
if the plain text abcd corresponds to the ciphertext efgh find the key used to encrypt/decrypt it