Synonyms of authenticated

1 Syllable
vouch
2 Syllables
warrant, confirm, prove, for-sure, attest, sure-thing
3 Syllables
endorse, guarantee, certify, witnessed, accredit, official, justify, verify
4 Syllables
validate, authorize, substantiate, honest-to-god, really-truly
5 Syllables
corroborate, circumstantiated
6 Syllables
authoritative