ANSI ASC X9.95 Standard

The ANSI X9.95 standard for trusted timestamps expands on the widely used RFC 3161 - Internet X.509 Public Key Infrastructure Time-Stamp Protocol by adding data-level security requirements that can ensure data integrity against a reliable time source that is provable to any third party.

Applicable to both unsigned and digitally signed data, this newer standard has been used by financial institutions and regulatory bodies to create trustworthy timestamps that cannot be altered without detection and to sustain an evidentiary trail of authenticity.

Timestamps based on the X9.95 standard can be used to provide: A superset of the IETF's RFC 3161 protocol, the X9.95 standard includes definitions for specific data objects, message protocols, and trusted timestamp methods, such as digital signature, MAC, linked token, linked-and-signature and transient-key methods.

When verification is needed, the verifier uses the RSA public key for the purported interval to decrypt the timestamp token.

The X9.95 standard can be applied to authenticating digitally signed data for financial transactions, regulatory compliance, and legal evidence.

From a timestamp authority, a requestor acquires a trusted timestamp, which is passed to a verifier.
Generating a timestamp for unsigned data.
Generating a timestamp for signed data.