Secure XML: The New Syntax for Signatures and Encryption

12.4. Validation Data Syntax

This section describes additional elements that you can add to an XAdES to produce higher levels of trusted signatures.

12.4.1. The SignatureTimeStamp Element

A SignatureTimeStamp is a time stamp over the signature to prove that it existed before the stamped time. The intention is to show that the signature existed and was valid when dependence was made on it—even if any keys involved in the signature are later revoked. This element may be applied to an XAdES to produce an XAdES-T or to an existing XAdES-T to produce a new XAdES-T that contains multiple time stamps. Its schema follows:

Schema Definition:

<xsd:element name="SignatureTimeStamp"
             type="TimeStampType"/>

12.4.2. The CompleteCertificateRefs Element

A long-term ...