The three layers of payments
We structure digital payments into three technology areas: processing the payment, authenticating the parties, and the infrastructure that makes payments possible. Each area is written as a self-contained whole, but together they form a comprehensive picture.
Digital payment processing
The payment lifecycle from initiation to settlement: gateways, processors, account-to-account payments and reconciliation.
Open technology area → Area 02Secure authentication protocols
Strong customer authentication (SCA), bank IDs, OAuth 2.0 / FAPI and dynamic linking in the PSD2 environment.
Open technology area → Area 03Transaction infrastructure
SEPA schemes, TIPS and RT1, ISO 20022 messages, idempotency, availability and operational resilience.
Open technology area →One payment, three perspectives
When a consumer pays an online shop by bank transfer, payment processing determines how the payment request is created, how its status is tracked and how it is reconciled with the accounts. Authentication ensures that the payer is who they claim to be and that the provider relaying the payment is entitled to use the bank's interface. Transaction infrastructure, in turn, ensures that the funds actually move from one bank to another reliably and quickly.
The layers depend on one another. Even the best user interface cannot compensate for weak authentication, and strong authentication is of little help if the infrastructure cannot process the payment around the clock. That is why we assess every technology from the perspective of the whole chain.
Our content is based primarily on legislation, publications by standard-setting bodies and material from public authorities. Where we refer to individual providers, the discussion is limited to payment technology and is neither a recommendation nor an assessment of a service's suitability for any particular purpose.