Customer Experience Guidelines
The Standards support both redirection and decoupled authentication to allow a PSU to use the same authentication mechanisms, whether using an AISP or PISP, as they do accessing their ASPSP directly.
Other Journeys in ‘v3.1.9’.
Redirection based authentication has a range of possible experiences for a PSU based on whether the PSU has an ASPSP app or not, and the device on which the PSU is consuming the TPP (AISP/PISP/CBPII) service.
The FCA have made clear in their Approach document that PSUs must be able to authenticate using the authentication methods they are accustomed to using via the banking application (‘app’) on a mobile phone if accessing accounts via a TPP.
We have used one example of an AISP and PISP journey to demonstrate how redirection flows must work. These apply to variations in AIS/PIS/CBPII journeys related to the order of application of SCA and are covered in sections 5, 6 and 7.
PSU Authentication with the ASPSP using browser based redirection from an AISP for an AIS request. This enables a PSU to authenticate with their ASPSP while using an AISP for an AIS service, using the same web based authentication method which the PSU uses when accessing the ASPSP web channel directly.
This version was published 9 Months ago
21 Oct 2021
PSU Authentication with the ASPSP using browser based redirection for a PIS request. This enables a PSU to authenticate with their ASPSP while using a TPP for the PIS service, using the same web based authentication method which they use when accessing the ASPSP web channel directly.
PSU authentication with the ASPSP using the ASPSP mobile app installed on the same device on which the PSU is consuming the AISP service. This enables the PSU to authenticate with the ASPSP while using an AISP for an AIS service using the same ASPSP app based authentication method which they use when accessing the ASPSP mobile channel directly.
PSU authentication, with the ASPSP using the ASPSP mobile app installed on the same device on which the PSU is consuming the PISP service. This enables the PSU to authenticate with the ASPSP while using a PISP for a PIS service using the same ASPSP app based authentication method that they use when accessing the ASPSP mobile channel directly.
It is possible that a PSU using a mobile device does not have their ASPSP mobile app installed, or their ASPSP does not provide an app at all. In these instances, the TPP app will need to launch the native mobile browser in order to present the PSU with their ASPSP's web channel to authenticate.
It is becoming common for TPPs to provide PSUs, using a desktop browser, with a way to authenticate using their ASPSP mobile app. This is a variant of a decoupled redirection flow where a TPP presents the PSU a QR code as an identifier.
A major addition to the Open Banking standards known as “Decoupled” authentication, where typically the PSU uses a separate secondary device to authenticate with the ASPSP. This model allows for a number of innovative solutions and has the added benefit of allowing a PSU to use their mobile phone to authenticate. Taking advantage of biometrics for SCA, where they are engaging with a PISP through a separate terminal, such as a point of sale (POS) device.
We have used examples for a PIS journey, but the same principles apply for AIS and CBPII journeys.
Under the Decoupled standard, the following customer experiences are available
A decoupled authentication flow, where the PSU provides a static identifier to the TPP (AISP/PISP/CBPII) which is used by the ASPSP to notify the PSU, such that the PSU can authenticate using the ASPSP app on a separate device.
A decoupled authentication flow where the PSU provides a dynamic identifier generated with their ASPSP to the TPP (AISP/PISP/CBPII) which is then used by the ASPSP to identify the PSU through the ASPSP app to authenticate and action the TPP request.
PSU provides a TPP (AISP/PISP/CBPII) generated unique identifier to the ASPSP to identify the request from the TPP User Journey A decoupled authentication flow where the PSU provides a dynamic identifier generated by the TPP (AISP/PISP/CBPII), which is then used by the ASPSP to identify the PSU through the ASPSP app to authenticate and action…
TPP (AISP/PISP/CBPII) passes the PSU’s stored unique identifier to the ASPSP to identify the PSU User Journey A decoupled authentication flow where the TPP (AISP/PISP/CBPII) provides the ASPSP a stored PSU identifier, generated by the ASPSP from a previous PSU transaction. This is used by the ASPSP to notify the PSU such that the PSU…
SCA -RTS includes a number of exemptions from the application of strong customer authentication, which include payments made to trusted beneficiaries, low value payments and payment based on transaction risk analysis. The application or not of SCA and the exact implementation of an SCA exemption is at the ASPSP’s discretion.
This section highlights the OB API Standard capabilities to allow PISPs to provide sufficient information about a transaction and about the PSU (if available) to enable the ASPSP to determine whether or not the exemptions are applicable.
SCA- RTS includes a number of available exemptions which permit an ASPSP not to apply SCA based on the availability of certain criteria, which consider factors such the amount, the beneficiary and the risk analysis of the transaction.
User Journey After the PSU has successfully initiated a payment initiation through a PISP, and details were held for future use (as per Single Domestic Payments – a/c selection @ PISP, item #11), this Journey can be used for initiating subsequent transactions. The PISP will provide to the ASPSP in all subsequent transactions a hint…
The EBA notes that “there would appear to currently be three main ways or methods of carrying out the authentication procedure of the PSU through a dedicated interface, and APIs in particular, namely redirection, embedded approaches and decoupled approaches (or a combination thereof). In the cases of redirection and decoupled approaches, PSU’s authentication data is exchanged directly between PSUs and ASPSPs, as opposed to embedded approaches, in which PSU’s authentication data is exchanged between TPPs and ASPSPs through the interface.”
PSD2 requires strong customer authentication to be performed in certain circumstances. The RTS requires that this application of strong customer authorisation is based on the use of elements, which are categorised as knowledge (something only the user knows), possession (something only the user possesses) and inherence (something the user is). These elements require adequate security features, which include ensuring that they are applied independently, so that the breach of any element does not compromise the reliability off the other.
ASPSPs implementing redirection should note that the FCA Approach document (Payment Services Regulations 2017 and the Electronic Money Regulations 2011) states it is not aware of any reason for ASPSPs to request strong customer authentication more than once when facilitating authentication for a single session of access to account information or a single payment initiation.
The Open Banking 2.0 standards specified redirection authentication flows only and the current ASPSP implementations of redirection are predominantly browser-based, whereby the PSU is redirected from the TPP app or website to the ASPSP’s website in order to authenticate. It is essential that when redirection is implemented it also allows for the PSU to use their ASPSP mobile app to authenticate, if the PSU uses this method of authentication when accessing their ASPSP’s channel directly.
Redirection has a specific TPP channel and device dependency and therefore cannot support channel agnostic use cases that involve telephony, POS, and IoT devices, or where physical PSU interaction is either not possible or not required within the TPP channel. These use cases can be supported using a decoupled approach to authentication.
In view of the above, the Open Banking 3.0 standards will support both redirection and decoupled authentication to allow a PSU to use the same authentication mechanisms while using an AISP or PISP as they use when accessing the ASPSP directly.
The general principles that apply relating to authentication are:
1. ASPSPs authenticate: PSU needs to go through a strong customer authentication (SCA) at their ASPSP in order for a TPP request (i.e. access to information or payment initiation) to be actioned by the ASPSP.
2. PSUs must have their normal authentication methods available:A PSU must be able to use the elements they prefer to authenticate with their ASPSP if supported when interacting directly with their ASPSP.
3. Parity of experience: The experience available to a PSU when authenticating a journey via a TPP should involve no more steps, delay or friction in the customer journey than the equivalent experience they have with their ASPSP when interacting directly.
4. Strong Customer Authentication: It is not expected that SCA would be required more than once when facilitating authentication for a single session of access to account information or a single payment initiation.
5. No Obstacles: ASPSPs must not create unnecessary delay or friction during authentication including unnecessary or superfluous steps, attributes, or unclear language, e.g. advertising of ASPSP products or services, language that could discourage the use of TPP services or additional features that may divert the PSU from the authentication process.
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