Validating identity certificate
In art and antiques, certificates are of great importance for authenticating an object of interest and value.
Certificates can, however, also be forged, and the authentication of these poses a problem.
To validate a certificate, a certificate user verifies the digital signature on the certificate by performing calculations, verifies that the current time is within the certificate’s validity period, and may need to validate a certification path involving additional certificates.
Deprecated Term: IDOCs SHOULD NOT use this synonym [valid signature].
In contrast with identification, which refers to the act of stating or otherwise indicating a claim purportedly attesting to a person or thing's identity, authentication is the process of actually confirming that identity.
It might involve confirming the identity of a person by validating their identity documents, verifying the authenticity of a website with a digital certificate, determining the age of an artifact by carbon dating, or ensuring that a product is what its packaging and labeling claim to be.
Currency and other financial instruments commonly use this second type of authentication method.
Bills, coins, and cheques incorporate hard-to-duplicate physical features, such as fine printing or engraving, distinctive feel, watermarks, and holographic imagery, which are easy for trained receivers to verify.
These external records have their own problems of forgery and perjury, and are also vulnerable to being separated from the artifact and lost.This can be accomplished through a written evidence log, or by testimony from the police detectives and forensics staff that handled it.Some antiques are accompanied by certificates attesting to their authenticity.Centralized authority-based trust relationships back most secure internet communication through known public certificate authorities; decentralized peer-based trust, also known as a web of trust, is used for personal services such as email or files (pretty good privacy, GNU Privacy Guard) and trust is established by known individuals signing each other's cryptographic key at Key signing parties, for instance.The second type of authentication is comparing the attributes of the object itself to what is known about objects of that origin.
For instance, the son of Han van Meegeren, the well-known art-forger, forged the work of his father and provided a certificate for its provenance as well; see the article Jacques van Meegeren.