title: How to Proceed 3D Secure transactions for cards that are stored in Vault using BrainTree API
body: <p>I have tried braintree API into my Dotnet webform application and was able to create transactions successfully. Now i got stuck up in one of the issues of setting up transactions for 3D secure verification for Cards that are stored in Braintree Vault.</p>
  
  <p>In the API they have mentioned to pass the NONCE FROM SERVER and amount from Client side to verify the transaction. But however im unable to get that link. Also im very much confused in accessing Liability Shifted concept. Can i have better explanation on this?</p>
  
  <p>I have gone through the API very thoroughly but unable to figure out this issue.</p>
  
  <p><strong>My Requirement</strong>: I need to create 3DSecure transactions within my applications for cards that are enabled for 3D Secure. How ever if a customer did not enable 3D secure i should be able to complete the transaction.(This i understood by passing 3D Secure - Required attribute to false from server side)
  Now i also need to save the card details in Vault for Saved Cards Section. So when im trying to invoke the 3DSecure for Saved cards section the response.nonce that was generated from Client side is same the Nonce that was generated at Server side. So it says NONCE ALREADY USED.</p>
  
  <p>So please help me in this regard. Thanks in advance.</p>
  
  <p>Srikanth</p>