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
acsTransIDACS Transaction ID	Required
challengeAddCodeChallenge Additional Code	Conditional
challengeCancelChallenge Cancelation Indicator	Conditional
challengeDataEntryChallenge Data Entry	Conditional
challengeDataEntryTwoChallenge Data Entry 2	Conditional
challengeHTMLDataEntryChallenge HTML Data Entry	Conditional
challengeNoEntryChallenge No Entry	Conditional
challengeWindowSizeChallenge Window Size	Required
deviceBindingDataEntryDevice Binding Data Entry	Conditional
infoContinueIndicatorInformation Continuation Indicator	Conditional
messageExtensionMessage Extension	Conditional
messageTypeMessage Type	Required
messageVersionMessage Version Number	Required
oobAppStatusOOB App Status	Conditional
oobAppURLIndOOB App URL Indicator	Required
oobContinueOOB Continuation Indicator	Conditional
resendChallengeResend Challenge Information Code	Conditional
sdkCounterStoASDK Counter SDK to ACS	Required
sdkTransIDSDK Transaction ID	Required
threeDSRequestorAppURL3DS Requestor App URL	Conditional
threeDSServerTransID3DS Server Transaction ID	Required
trustListDataEntryTrust 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