In the SOAPEnvelope.

I wants to signed the xml element 'EncryptedAssertion'.

<EncryptedAssertion>
    <EncryptedData>....</EncryptedData>
</EncryptedAssertion>

using the below Transform algorithm (STR-Transform)

<Transform Algorithm=".0#STR-Transform">
    <o:TransformationParameters>
        <CanonicalizationMethod Algorithm=";/>
    </o:TransformationParameters>
</Transform>

Whats kind of Transform class would be helpful here?

In C#, I only can see just the following Transform classes. Which i thinks none of these relates to the STS-Transform.

How you will suggest to signed the "<EncryptedAssertion" element using the SecurityTokenRequest-Transform?

Thanks in advance for any tips :)