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source/decoupled_authentication.rst

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+.. _decoupled_authentication:
+
+Decoupled Authentication
+=========================
+
+The decoupled authentication is a feature that allows you to authenticate
+the cardholder during the payment process. This is a different approach to
+challenge flow where the authentication is done in one simultaneous flow.
+The decoupled authentication is a two-step process where the authentication
+is done in a separate flow from the payment process.
+
+The ACS can determine decoupled authentication fallback for a authentication transaction.
+If a fallback is determined, `threeDSRequestorPriorAuthenticationInfo`is required.
+
+The requestor can set the TTL for the transaction by setting the `threeDSRequestorDecMaxTime`.
+The threeDSRequestorDecMaxTime accepts numeric values between `00001` and `10080`which
+determines the TTL in minutes.
+
+Once the cardholder has authenticated the transaction and the 3-D secure server has
+received the `RReq`, the 3-D secure server will notify the requestor by utilizing the
+`notificationURL` which will contain the `threeDSServerTransID` and `messageVersion`.
+If no RReq is received within the TTL, the transaction will be considered as failed.
+The 3-D secure server will only try to notify the requestor once.
+
+The requestor shall use the `threeDSServerTransID` to retrieve the authentication value
+by making a request towards the `/postauth` endpoint.