Indicates the authentication type of the cardholder.

Output field, returned in the response (IPN and Return URL).

Format enum
Possible values
  • “Empty” if the buyer is not correctly authenticated.
  • FRICTIONLESS: buyer authentication without interaction with the ACS. Value returned only in 3DS v2.
  • CHALLENGE: interactive authentication of the cardholder (OTP entry or response to a series of questions). Value returned in 3DS v1 and 3DS v2.
Category Authentication of cardholder.