The System.Security.Cryptography.Xml.XmlDsigEnvelopedSignatureTransform class removes the <Signature> element from an XML document before the digest is computed. With this transform, you can sign and verify all elements of an XML document except the XML digital signature elements.
Although you can create and insert a signature into an XML document, verifying the modified document using the embedded signature will fail because the document now has additional elements. This transform removes the <Signature> element and allows you to verify the document using its original form.
Use the System.Security.Cryptography.Xml.XmlDsigEnvelopedSignatureTransform class whenever you create an enveloped signature.
For more information about the enveloped signature transform, see Section 6.6.4 of the XMLDSIG specification, which is available from the W3C at www.w3.org/TR/xmldsig-core/.