Every animated end-to-end flow on PayProbe, in one place — card authorization, clearing and settlement, 3-D Secure, tokenization, open banking, EUDI Wallet SCA, TR-34 key exchange, agentic payments and more. Each diagram steps through the actors and messages with an explanation per hop.
25 scenarios · 14 flows
Card Rails
Card Authorization
27 steps
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Card PresentIn-store chip or contactless payment — from card tap through online authorization, clearing, and final settlement of funds to the merchant.
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E-commerce (3DS)Card-not-present online checkout with EMV 3-D Secure (SCA) — from checkout through risk-based or challenge authentication to authorization.
Auth → Clearing → SettlementThe three phases of a card payment. Authorization is real-time and only reserves funds; clearing and settlement run in batch (typically T+1/T+2) and actually move the money.
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Dispute & ChargebackWhen a cardholder disputes a transaction it enters a structured, multi-stage process between issuer, scheme, and acquirer — potentially ending in scheme arbitration.
Authorization (0100/0110)A request/response pair travels from the terminal to the issuer and back. The MTI changes from request (x100/x200) to response (x110/x210) on the return path.
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Reversal (0400/0410)When a transaction fails after authorization — timeout, no response, or a void — a reversal unwinds the issuer hold so funds are not left reserved.
FrictionlessEMV 3DS2 risk-based authentication where the issuer ACS approves on data alone — no cardholder interaction. The common path for low-risk transactions.
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ChallengeWhen risk or regulation requires a step-up, the issuer ACS challenges the cardholder directly (OTP, app approval, or biometric) before returning the result.
ProvisioningAdding a card to a wallet (Apple Pay / Google Pay). The real PAN (FPAN) is exchanged for a device token (DPAN) after the issuer verifies the cardholder (ID&V).
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Tokenized PaymentA wallet payment uses the DPAN and a one-time cryptogram. The network de-tokenizes back to the real FPAN before routing the authorization to the issuer.
Payment Initiation (Redirect)A "pay by bank" checkout under PSD2: the PISP creates the payment order over the ASPSP's API, the payer is redirected to their bank for SCA with dynamic linking, and the payment settles as a (usually instant) credit transfer — no card rails involved.
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Account Access Consent (AIS)How an AISP gets read access to accounts: an explicit consent resource is created at the bank, the PSU authorises it with SCA once, and the AISP then reads balances and transactions within that consent's scope and lifetime.
SCA Payment AuthenticationPSD2 strong customer authentication run through the EUDI Wallet: the issuer's ACS acts as an OID4VP verifier, the wallet shows the holder the exact amount and payee, and the WSCD-signed presentation becomes an authentication code with dynamic linking built in.
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Credential Issuance (OID4VCI)How a credential gets into the wallet over OID4VCI: the holder authenticates to the issuer at the required assurance level, the wallet proves possession of a hardware-bound key, and the issuer returns a selectively disclosable credential bound to that key.
Merchant-Presented (MPM)The merchant displays an EMV QR code (static or dynamic); the consumer scans it with their wallet app to initiate and authorise the payment.
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Consumer-Presented (CPM)The consumer's wallet generates a one-time QR / barcode; the merchant scanner reads it and pushes the transaction, like a contactless tap.
Human PresentA user delegates shopping to an AI agent but approves the final cart themselves. The merchant signs the exact cart (CartMandate), the user counter-signs it on a trusted surface, and a PaymentMandate carries agent-presence signals to the network/issuer alongside normal authorization.
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Human Not Present"Buy the tickets the moment they drop, budget $1000." The user signs an IntentMandate up front and the agent completes the purchase later, in their absence — the merchant decides whether the intent is specific enough to fulfil, or forces the user back into session.
Tokenised-Deposit PaymentA cross-border payment on SWIFT's shared ledger: the sending bank records a commitment, smart-contract logic runs the compliance gate, the receiving bank confirms on-ledger, tokenised deposits move with immediate finality, and the ledger coordinates final settlement on existing infrastructure — available 24/7.
TR-34 Two-PassRemote symmetric key (KEK) distribution to an HSM/terminal using RSA. The two-pass protocol binds the key to a fresh nonce from the receiving device to prevent replay.
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TR-34 One-PassA streamlined push where the host already holds the receiving device credentials, so no live nonce exchange is needed — used for bulk or pre-provisioned distribution.
Contactless Tap (ISO 14443)The low-level handshake between a contactless reader (PCD) and card/phone (PICC): RF activation, anti-collision, protocol activation, then the EMV application exchange.
DESFire EV3 (AES)A modern MIFARE tap: ISO 14443-4 activation, application selection, AES mutual authentication (AuthenticateEV2First), then encrypted-and-MACed reads and an atomic value transaction — the pattern behind transit purses and access badges.
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Classic (Crypto1) — brokenThe legacy MIFARE Classic 3-pass authentication over the proprietary Crypto1 cipher — worth understanding because a huge installed base still runs it, and because every step shown here has a published attack.
Trade → Risk → SettlementHow one trade moves through Nasdaq Calypso without leaving the platform: booked in the front office, it updates risk and P&L in real time, feeds collateral, and is confirmed, settled and booked to the sub-ledger — all off the same shared trade object.