Policy
Check the XAdES portions of a digital signature
This policy setting lets you specify whether or not Office 2016 checks the XAdES portions of a digital signature, if present, when validating a digital signature for a document. If you enable this policy setting, Office 2016 checks the XAdES portions of a digital signature when validating it. If you disable or do not configure this policy setting, Office 2016 only validates XML-DSig and XAdES-BES portions of a digital signature.
65ac62a9a68a L_CheckTheXAdESPortionsOfADigitalSignature Registry
Copy registry mappings
HKCU\software\policies\microsoft\office\16.0\common\signatures\xadesvalidationlevel (enabled) = 1
HKCU\software\policies\microsoft\office\16.0\common\signatures\xadesvalidationlevel (disabled) = 0Policy notes
This policy setting lets you specify whether or not Office 2016 checks the XAdES portions of a digital signature, if present, when validating a digital signature for a document. If you enable this policy setting, Office 2016 checks the XAdES portions of a digital signature when validating it. If you disable or do not configure this policy setting, Office 2016 only validates XML-DSig and XAdES-BES portions of a digital signature.