authentication vs assay-mark

authentication and assay-mark both are nouns.

Word	Noun	Adjective	Verb	Adverb
authentication	Yes	No	No	No
assay-mark	Yes	No	No	No

As nouns, authentication and assay-mark are synonyms defined as:

authentication and assay-mark: a mark on an article of trade to indicate its origin and authenticity

Other synonyms of authentication include hallmark.

authentication (noun)	assay-mark (noun)
validating the authenticity of something or someone	a mark on an article of trade to indicate its origin and authenticity
a mark on an article of trade to indicate its origin and authenticity