CReq — Challenge Request

The CReq message initiates Cardholder interaction in a Challenge Flow and can be used to carry authentication data from the Cardholder.

Direction 3DS SDK/Browser → ACS

Full message description

The CReq message initiates Cardholder interaction in a Challenge Flow and can be used to carry authentication data from the Cardholder. • App-based—The CReq message is sent by the 3DS SDK. There are two or more CReq messages per challenge as multiple back-and-forth attempts between the ACS and the Cardholder may be required to complete the authentication. • Browser-based—The CReq message is formed by the 3DS Server and is posted through the Cardholder Browser. There is only one CReq message per challenge.

22 top-level fields

Baseline inclusion. Effective requirements depend on transaction context. Check the field’s conditions and FAQ qualifications; select channel and category in the explorer.

Field	Baseline inclusion
`acsTransID`ACS Transaction ID	Required
`challengeAddCode`Challenge Additional Code	Conditional
`challengeCancel`Challenge Cancelation Indicator	Conditional
`challengeDataEntry`Challenge Data Entry	Conditional
`challengeDataEntryTwo`Challenge Data Entry 2	Conditional
`challengeHTMLDataEntry`Challenge HTML Data Entry	Conditional
`challengeNoEntry`Challenge No Entry	Conditional
`challengeWindowSize`Challenge Window Size	Required
`deviceBindingDataEntry`Device Binding Data Entry	Conditional
`infoContinueIndicator`Information Continuation Indicator	Conditional
`messageExtension`Message Extension	Conditional
`messageType`Message Type	Required
`messageVersion`Message Version Number	Required
`oobAppStatus`OOB App Status	Conditional
`oobAppURLInd`OOB App URL Indicator	Required
`oobContinue`OOB Continuation Indicator	Conditional
`resendChallenge`Resend Challenge Information Code	Conditional
`sdkCounterStoA`SDK Counter SDK to ACS	Required
`sdkTransID`SDK Transaction ID	Required
`threeDSRequestorAppURL`3DS Requestor App URL	Conditional
`threeDSServerTransID`3DS Server Transaction ID	Required
`trustListDataEntry`Trust List Data Entry	Conditional

Source

EMV_3DS_CoreSpec_v2.3.1.1_20230530.pdf · Section 2.4.3, Table B.3

Official EMVCo specifications · Coverage and review limits