something which validates or confirms the authenticity of something / (computing) proof of the identity of a user logging on to some network / a hallmark or assay-mark on a piece of metalwork

The quality of being genuine or not corrupted from the original, of having the same origin (or attribution, commitment, intention, etc.) as claimed.

The quality of being authentic; authenticity.

(archaic) Authentic.

(civil law) A collection of the Novels or New Constitutions of Justinian, by an anonymous author.

In an authentic manner; with the requisite or genuine authority.

(law) In the law of evidence, being a piece of evidence that will automatically be presumed authentic for purposes of admissibility based on the character of the evidence itself. Examples include certified copies of public or business records, official publications of government agencies, and newspaper articles.

(music, chiefly US) A cadence involving the resolution of the dominant chord (V) to the root chord (I).

plural of authentic cadence

A seal on paper appended to a specific artwork which is made to demonstrate that the item is authentic.