Passkeys integrate with 3DS at three points. First, as a challenge flow replacement: when the ACS requires step-up authentication, it triggers a passkey challenge instead of sending an SMS OTP — reducing authentication time from 20-45 to 3-8 seconds. Second, via Secure Payment Confirmation (SPC): transaction details are shown in a browser-native passkey dialog, meeting dynamic linking requirements. Third, as a frictionless risk signal: when merchants use passkeys for customer login, that data can be passed in the 3DS request, enabling issuers to approve transactions without a challenge step. G+D Netcetera's 3DS Passkey Server handles the first and third; SPC is handled at the browser layer.