Informationallog level you will see log entries indicating successful validation of the plugin:
Digital Signaturestab of the properties window.
Detailsyou can view the digital signature on the assembly code and validate the issuer and publisher of the digital signature.
allowUnsignedAssembliesattribute on the
codeSigning(optionally sign it with your own CA's certificate).
Trusted Publishersstore on all machines which will use the plugin