PAYMENTS SIGNAL REFERENCE ARCHITECTURE · SYNTHETIC / TRAINING ONLY

Digital wallets, network tokenisation, 3-D Secure, and cardholder-data boundaries

See how a wallet enrols a card, uses a payment token and transaction credential, invokes authentication when required, and keeps raw card data inside controlled boundaries.

Payments Signal reference architecture v1 · reviewed 2026-07-23

Reference architecture—not a scheme mandate. This blueprint shows responsibility and trust boundaries, not a licensed token-service or wallet specification. Device attestation, issuer identity-and-verification methods, token assurance, cryptographic protocols, liability, authentication exemptions, fallback, and PCI DSS scope must be assessed against the actual providers, channels, and current rules.

Audience and purpose

Wallet, card, digital-channel, authentication, security, fraud, and merchant-platform architects.

Components

Cardholder device and wallet

Protects the user session and requests provisioning or payment with device context.

Kind
channel
Owner
Wallet provider and device owner
Responsibilities
  • Authenticate the user under wallet policy
  • Protect device-bound credentials
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Device integrity
  • User authentication
  • No credential in analytics logs
Failure modes
  • Lost device
  • Compromised wallet session
  • Repeated provisioning
Recovery
  • Suspend the token
  • Re-enrol only after issuer and wallet controls pass
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Wallet provisioning service

Coordinates card enrolment, eligibility, identity-and-verification, and token request.

Kind
service
Owner
Wallet provider
Responsibilities
  • Create a correlated provisioning case
  • Carry issuer verification outcome without inventing approval
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Card eligibility
  • Device and account risk
  • Step-up verification
Failure modes
  • Provisioned to wrong user
  • Orphan request
  • Repeated verification
Recovery
  • Suspend pending tokens
  • Resume from the issuer's confirmed outcome
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Token service provider and token vault

Maps a payment token to the underlying account and manages token lifecycle and domain controls.

Kind
security
Owner
Network or authorised token service provider
Responsibilities
  • Issue a constrained payment token
  • Manage activation, suspension, replacement, and deletion
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Token domain restriction
  • Vault access
  • Lifecycle audit
  • Cryptographic key control
Failure modes
  • Token used outside its domain
  • Vault unavailable
  • Stale token status
Recovery
  • Decline or suspend
  • Recover token state from authoritative lifecycle evidence
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Issuer digitisation and risk service

Decides card eligibility, identity verification, token assurance, and lifecycle action.

Kind
control
Owner
Issuer digital cards and fraud
Responsibilities
  • Approve or decline provisioning
  • Bind assurance and verification method to the token record
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Customer verification
  • Account and card status
  • Fraud and device risk
Failure modes
  • False provisioning approval
  • Verification timeout
  • Lifecycle mismatch
Recovery
  • Suspend until state is confirmed
  • Reconcile issuer and token-service records
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Merchant wallet acceptance

Accepts tokenised credentials and binds them to the transaction, channel, amount, and merchant.

Kind
gateway
Owner
Merchant payment platform
Responsibilities
  • Request a transaction credential
  • Avoid storing raw credentials in commerce systems
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Merchant and amount binding
  • Replay control
  • Secure checkout
Failure modes
  • Credential replay
  • Amount changed after authentication
  • Fallback exposes raw data
Recovery
  • Reject changed context
  • Create a new authenticated attempt
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

3-D Secure access and authentication domains

Coordinates merchant/acquirer, interoperability, and issuer authentication responsibilities for an online card payment.

Kind
external-network
Owner
Merchant, scheme directory, and issuer access-control owners
Responsibilities
  • Exchange authentication data
  • Return a correlated frictionless, challenge, unavailable, or failed outcome
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Protocol version
  • Transaction and channel binding
  • Challenge integrity
Failure modes
  • Authentication unavailable
  • Late challenge
  • Protocol downgrade
Recovery
  • Apply documented fallback policy
  • Do not reinterpret authentication as authorisation
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Card authorisation and clearing rail

Carries the payment token and transaction credential through normal card authorisation and later clearing.

Kind
external-network
Owner
Acquirer, network, and issuer
Responsibilities
  • Route tokenised authorisation
  • Preserve token and authentication context for risk and reconciliation
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Token status
  • Cryptogram validation
  • Authorisation and clearing correlation
Failure modes
  • Token valid but cryptogram invalid
  • Authentication data lost
  • Token-to-account mismatch
Recovery
  • Decline precisely
  • Investigate across token and card references
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Token, authentication, and fraud operations

Investigates provisioning, token lifecycle, authentication, authorisation, and customer-reported events across organisations.

Kind
operations
Owner
Issuer, wallet, merchant, and network operations
Responsibilities
  • Correlate token, device, authentication, and payment references
  • Coordinate suspension and recovery
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Least-privilege case access
  • Evidence retention
  • No raw credential in case notes
Failure modes
  • Unowned fraud case
  • Token suspended in one system only
  • Sensitive data copied into tickets
Recovery
  • Contain token use
  • Synchronise authoritative status
  • Redact and remediate exposed data
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Interfaces

Provisioning request

wallet-user → wallet-provisioning

Carry authenticated device, user, and card-enrolment context.

Contract
api · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Keep the request pending when issuer outcome is uncertain.

Issuer eligibility and verification

wallet-provisioning → wallet-issuer

Obtain issuer approval and assurance evidence.

Contract
message · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Do not issue an active token without a confirmed decision.

Token issuance decision

wallet-issuer → wallet-token-service

Authorise token issuance and lifecycle state.

Contract
control · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Reconcile mismatched issuer and token-service outcomes.

Device token and credential

wallet-token-service → wallet-user

Deliver a constrained token representation and payment capability.

Contract
api · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Suspend on device or lifecycle compromise.

Wallet payment

wallet-user → wallet-merchant

Submit tokenised payment data bound to transaction context.

Contract
api · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Reject replayed or context-mismatched credentials.

Authentication request

wallet-merchant → wallet-3ds

Request 3-D Secure authentication when applicable.

Contract
message · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Return a distinct unavailable or failed state.

Issuer authentication

wallet-3ds → wallet-issuer

Let the issuer assess or challenge the cardholder.

Contract
message · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Preserve challenge outcome and protocol evidence.

Tokenised authorisation

wallet-merchant → wallet-card-rail

Request card authorisation with token and authentication context.

Contract
message · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Do not equate authentication success with issuer approval.

Token resolution and assurance

wallet-card-rail → wallet-token-service

Validate token state, domain, and transaction credential.

Contract
control · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Decline invalid token or credential with controlled diagnostics.

Lifecycle and fraud event

wallet-card-rail → wallet-operations

Open a correlated investigation or token action.

Contract
event · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Deduplicate repeated events and protect sensitive data.

Authored traces

Provision and spend a token

Follow a card from wallet enrolment to one authenticated, tokenised authorisation.

  1. Start enrolment — Provisioning requested. The wallet binds the request to the authenticated user and device.
  2. Ask the issuer — Eligibility under review. The wallet requests issuer eligibility and any required verification.
  3. Approve token issuance — Provisioning approved. The issuer records the verification and assurance decision.
  4. Issue a constrained token — Token active. The token service creates a token with domain and lifecycle controls.
  5. Bind the purchase — Payment context fixed. The merchant binds amount, merchant, and channel before authentication.
  6. Authenticate when required — Authentication outcome recorded. 3-D Secure returns an outcome; it does not approve the payment.
  7. Authorise the tokenised payment — Card authorisation decided. The issuer decides the card payment using token and transaction context.

Stress cases

Provisioning outcome is lost

The token service response is lost after issuer approval.

Last confirmed state
Issuer approval exists; token state is uncertain.
Settlement
No purchase settlement has occurred.
Funds and entries
No purchase funds moved.
Next owner
Issuer digital-card operations
Safe action
Query the token lifecycle by the original provisioning reference before retry.
Evidence required
  • Issuer decision
  • Token request ID
  • Token-service lifecycle state
Recovery
  • Confirm or cancel the existing token
  • Synchronise wallet and issuer status

3-D Secure is unavailable

Authentication cannot return a conclusive outcome.

Last confirmed state
The purchase context exists; authentication is unavailable.
Settlement
No card settlement has occurred.
Funds and entries
No issuer authorisation hold is confirmed.
Next owner
Merchant payment operations
Safe action
Apply the merchant, issuer, regulatory, and scheme fallback policy; do not label unavailable as authenticated.
Evidence required
  • Protocol error
  • Transaction reference
  • Fallback rule
Recovery
  • Return a clear outcome
  • Retry only if the protocol permits
  • Keep the new attempt distinct

Token credential is replayed

A transaction credential is reused outside its intended context.

Last confirmed state
The original payment attempt is already known.
Settlement
Settlement state of the original attempt must be checked separately.
Funds and entries
A second hold or posting must not be assumed valid.
Next owner
Issuer fraud operations
Safe action
Decline the replay, contain the token if policy requires, and correlate the original transaction.
Evidence required
  • Token reference
  • Credential and domain checks
  • Original authorisation
Recovery
  • Block repeated use
  • Investigate compromise
  • Replace or resume the token under controlled lifecycle rules

Design decisions

Which system is authoritative for token lifecycle?

  • Token service authoritative — Keeps issuance and lifecycle central but demands rapid issuer and wallet synchronisation.
  • Issuer mirror authoritative — Improves issuer control but risks divergence unless every token event is reconciled.

Name one lifecycle authority and define reconciliation, suspension, and recovery for every participant.

How should authentication and authorisation states relate?

  • Separate states — Preserves the fact that identity evidence and funds approval answer different questions.
  • Single success flag — Hides unavailable, challenged, declined, and approved distinctions and weakens troubleshooting.

Store protocol outcome, issuer authentication outcome, and card authorisation outcome separately.

Sources and disclosed synthesis