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.
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.