attest vs authenticate

attest and authenticate both are verbs.

Word	Noun	Adjective	Verb	Adverb
attest	No	No	Yes	No
authenticate	No	No	Yes	No

As verbs, authenticate is a hyponym of attest; that is, authenticate is a word with a more specific, narrower meaning than attest:

attest: provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
authenticate: establish the authenticity of something

Other hyponyms of attest include reflect, reflect, notarise, notarize, condemn.

attest (verb)	authenticate (verb)
authenticate, affirm to be true, genuine, or correct, as in an official capacity	establish the authenticity of something
provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
give testimony in a court of law
establish or verify the usage of