SecureBlackbox 16: How do I modify 'Signature' element properties, e.g., <Id>?

First, you need to set up all properties needed for the signature, then call the Sign() method. This method will prepare everything for signing and create the Signature structure. The actual signing is performed in the Save() method, because canonicalization results and digest values can depend on the signature element placement in the XML document.

Next, to change the Signature element ID set the ID property as shown (C# notation):