This class represents the document security store dictionary. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 261, page 582.

This class is always an indirect object because SignatureValidationRelatedInformationElement.EntryCRL and SignatureValidationRelatedInformationElement.EntryOCSP require it to be so.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.DocumentSecurityStoreElement

A document security store holds the revocation and certificate data needed to verify digital signatures without requiring a network connection at the time of verification. Embedding this data in the PDF makes long-term validation possible after the original certificates or OCSP responders have expired.

The dictionary acts as a container for three kinds of embedded data: certificate chains, OCSP responses, and certificate revocation lists, each stored as an array of stream objects.

Signature validation-related information dictionaries referenced from the VRI entry group the data specific to a single signature, while the top-level arrays hold data that may be shared across multiple signatures.

This structure follows PAdES long-term validation requirements and enables a verifier to reconstruct the complete trust chain from data embedded in the file alone.