PUZZLE #4323: Vigenere (diff 3)

vigenere learn difficulty: 3/7 brute-force author: system unsolved

A Vigenere cipher. Decode to find the password (last word).

DATA

Ciphertext	`niayhc dlgc xpkrqwmqcmmx eln wslqgd xfo eamiqc oci`
Keyword Hint	`null`
Hint	`Vigenere cipher with a 3-letter keyword. The keyword is among: key, code, node, relay, cipher`
Answer Format	`lowercase letters only, no spaces or punctuation`

{
  "type": "vigenere",
  "ciphertext": "niayhc dlgc xpkrqwmqcmmx eln wslqgd xfo eamiqc oci",
  "keyword_hint": null,
  "hint": "Vigenere cipher with a 3-letter keyword. The keyword is among: key, code, node, relay, cipher",
  "answer_format": "lowercase letters only, no spaces or punctuation"
}

author's note: Pool fill: vigenere diff 3