4.1. 3-D Secure version determination

There are currently three 3-D Secure versions, 2.1.0, 2.2.0 and 2.3.1.

  1. If the preauth call returns a BIN not enrolled error, continue with 3DSv1.

  2. If acsInfoInd (2.1.0, 2.2.0, 2.3.1) is included, this indicates if ACS supports challenges or only attempts.

    To select between 2.1.0, 2.2.0 and 2.3.1, we suggest using the highest version that all parties support, including your implementation. Exemplified:

    • If dsEndProtocolVersion: 2.2.0 and acsEndProtocolVersion: 2.1.0, then the ACS does not support 2.2.0 and you must use 2.1.0

    • It would be safe to use 2.2.0 if dsEndProtocolVersion: 2.2.0 and acsEndProtocolVersion: 2.2.0

    • If acsStartProtocolVersion: 2.2.0 and acsEndProtocolVersion: 2.2.0, then the ACS is not able to receive messages with protocol version 2.1.0