Per the national website:

9/16/19 (Division C) 3.f.v. should read, edits in bold: "the Hill Cipher - Encrypting plaintext or decrypting ciphertext with a 2x2 encryption matrix or 3x3 decryption matrix provided” (the word Encrypting was misspelled)

11/19/19 (Division C) 3.e.vii. should read, edits in bold: "the Hill Cipher - encrypting plaintext or decrypting ciphertext given a 2x2 encryption matrix." (encryption replaces the incorrect term decryption)