Definition
Authentication is the process by which a third party — typically PSA/DNA, JSA, Beckett (BAS), SGC, or CGC — verifies that an item is authentic (a real signature, a real game-used jersey, a real prop). It results in a Certificate of Authenticity, Letter of Authenticity, or sealed slab/sticker, often referenced by an online database.
Why it matters
Authentication is the single largest value multiplier for unique items like autographs, game-used pieces, and props. A trusted authenticator's stamp can move price by 3–10x.
Example
A signed Tom Brady photograph submitted to JSA is authenticated as a real Brady signature, and JSA issues a numbered hologram and database entry.
Related terms
- Certificate of AuthenticityA document asserting that an item is authentic — credibility depends entirely on the issuer.
- Letter of AuthenticityA long-form authentication document, typically from a recognized third-party authenticator.
- Third-Party AuthenticatorAn independent company that authenticates items without being the buyer or seller.
- GradingA third-party numeric score of an item's condition, typically encapsulated in a tamper-evident slab.