All signed documents have two attachments: the The Case Audit Log and a zip file containing original data.
You can view these attachments by opening the signed document in a PDF Reader that support attachments, like Adobe Acrobat Reader.
The Case Audit Log is found in the file attachment named
caseauditlog.pdf. It contains information about who sent the case and how the case was signed.
The zip file containing the original data, is named
caseaudit.zip, and holds the original documents and the signature data. The signature data depends on the signature method used. The contents of the zip file can be used for verifying the signatures.