PUZZLE #3976: Vigenere (diff 7)

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

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

DATA

Ciphertext	`liwyrb dlgc xcbqgxej mmnrip vmcc e fshbor nbsrygmv pyiip kgaowqsfjo ivmpscmtopw ds rovksryv iars pkrioh yqildw urs fkzc niayhcn ejv wgh tpogcnmlq ggzlcb xgovq gmrrssd ipbsp`
Keyword Hint	`3-letter keyword`
Hint	`Vigenere cipher with a 3-letter keyword. Hint: the keyword relates to relay terminology.`
Answer Format	`lowercase letters only, no spaces or punctuation`

{
  "type": "vigenere",
  "ciphertext": "liwyrb dlgc xcbqgxej mmnrip vmcc e fshbor nbsrygmv pyiip kgaowqsfjo ivmpscmtopw ds rovksryv iars pkrioh yqildw urs fkzc niayhcn ejv wgh tpogcnmlq ggzlcb xgovq gmrrssd ipbsp",
  "keyword_hint": "3-letter keyword",
  "hint": "Vigenere cipher with a 3-letter keyword. Hint: the keyword relates to relay terminology.",
  "answer_format": "lowercase letters only, no spaces or punctuation"
}

author's note: Pool fill: vigenere diff 7