Dutch bank ASN blames Google Play Integrity for locking GrapheneOS out of iDEAL Wero

ASN Bank has told customers that its new iDEAL | Wero payment feature cannot be used on phones running non-Google Android builds such as GrapheneOS, because the bank's app performs a Google Play Integrity check during activation. The Dutch bank, which presents sustainability and privacy as core values, says it has no workaround and cannot promise when, or whether, alternative operating systems will be supported.

The exchange came to wider attention via Hacker News, through an issue thread on the PrivSec-dev banking-apps-compat-report repository, a community project that documents how banking apps behave on custom Android systems.

What ASN told customers

According to the thread, a customer complained to ASN after discovering that activating iDEAL | Wero in the ASN app triggers a Play Integrity verification that fails on their device. The complaint argued that a privacy-minded bank owned by the Dutch state should not depend on a Google-controlled gatekeeping mechanism, and asked ASN to switch to Android's open attestation instead.

The reply, translated from Dutch in the thread, shifted responsibility to the payment scheme. ASN said iDEAL | Wero operates under strict European privacy, security and anti-fraud rules and therefore sets high demands on the integrity of the devices using it. The service relies, the bank said, on the standard security checks built into conventional operating systems; because alternative systems skip or replace those protections, the payment scheme cannot vouch for the safety of a transaction.

ASN added that for joint payment initiatives it follows the security requirements set collectively by the participating parties, and that it is exploring with iDEAL | Wero whether alternative operating systems could be supported in future. That outcome depends on multiple parties and technical developments, and the bank said it can promise or guarantee nothing at this point. It closed by saying there is no solution that would let the customer use iDEAL | Wero on their phone, and no information on when broader support might arrive.

Notably, another participant in the same thread reported receiving an almost word-for-word identical reply from ASN, suggesting the bank is pooling complaints about the issue and answering them with a shared template.

How Play Integrity excludes alternative systems

Google's Play Integrity API lets an app verify that it is running on a Google-certified Android build with recognised Play services. Privacy-focused distributions such as GrapheneOS deliberately ship without that certification, so their users fail the check regardless of how well-hardened the system actually is. The verdict, in other words, measures alignment with Google rather than actual device security, and any app that treats the check as mandatory hands Google a de facto veto over which operating systems may run it.

Why it matters

The ASN case illustrates a structural problem with app-level integrity checks: a third party with its own commercial interests effectively decides which phone software is trustworthy enough for everyday banking. Because ASN frames the requirement as coming from the shared iDEAL | Wero framework rather than its own app, other banks adopting the same scheme may impose the same lockout as it extends beyond the Netherlands.

For users of GrapheneOS and similar de-Googled systems there is no bug to report and no setting to toggle: the app works fine until the integrity check decides otherwise. And the existence of Android's own hardware-backed, open attestation, which the complainant specifically pointed to, weakens the argument that Google's proprietary check is the only way to satisfy European fraud-prevention rules. Until banks accept attestation mechanisms they do not control, customers who remove Google from their phones will keep losing access to basic financial services, even from banks that advertise privacy as a principle.