authenticate vs demonstrate

authenticate and demonstrate both are verbs.

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

As verbs, demonstrate is a hypernym of authenticate; that is, demonstrate is a word with a broader meaning than authenticate:

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

Other hypernyms of authenticate include attest, certify, evidence, manifest.

authenticate (verb)	demonstrate (verb)
establish the authenticity of something	establish the validity of something, as by an example, explanation or experiment
	provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes
	give an exhibition of to an interested audience
	march in protest; take part in a demonstration