This post is actually really bad for a Hn post, it appears to be a reply to someone else hence the lack of context here, and the link appears to be a list of banking apps that are have some level of compatibility at all, not the official 12.
Our linked reply says most banking apps work on GrapheneOS and that only around 10% are unavailable due to banning a non-Google-certified OS. What we said about banks specifically permitted it means some of those former 10% of apps not allowing it began explicitly permitting it in one way or another. Some did it by removing or modifying certain checks while others did it by checking for GrapheneOS and potentially other operating systems via Android hardware attestation as an alternative to the Play Integrity API.
The way they fixed compatibility with GrapheneOS varies. Our post says around 90% of banking apps are working and around a dozen are known to have specifically made changes to support GrapheneOS. That mainly involves them no longer banning using it one way or another. Some did so by verifying GrapheneOS via the Android hardware attestation API but others simply fixed broken anti-tampering checks. Some apps including certain banking apps relaxed their Play Integrity API checks but we expect they'll undo that and use Android hardware attestation to support multiple alternatives otherwise banned by it. We don't choose what these apps do and would prefer if they entirely removed all of the misguided anti-tampering code and restrictions on what can be used. It still causes problems regularly for apps permitting GrapheneOS since the checks often have bugs or they don't permit newly supported devices promptly.
A dozen is the number of banks that whitelist Grapheneos keys via hardware attestation.
This post is actually really bad for a Hn post, it appears to be a reply to someone else hence the lack of context here, and the link appears to be a list of banking apps that are have some level of compatibility at all, not the official 12.
Our linked reply says most banking apps work on GrapheneOS and that only around 10% are unavailable due to banning a non-Google-certified OS. What we said about banks specifically permitted it means some of those former 10% of apps not allowing it began explicitly permitting it in one way or another. Some did it by removing or modifying certain checks while others did it by checking for GrapheneOS and potentially other operating systems via Android hardware attestation as an alternative to the Play Integrity API.
I didn't have time to review it, but there is some way to explicitly trust GrapheneOS. Maybe that is what they mean?
The way they fixed compatibility with GrapheneOS varies. Our post says around 90% of banking apps are working and around a dozen are known to have specifically made changes to support GrapheneOS. That mainly involves them no longer banning using it one way or another. Some did so by verifying GrapheneOS via the Android hardware attestation API but others simply fixed broken anti-tampering checks. Some apps including certain banking apps relaxed their Play Integrity API checks but we expect they'll undo that and use Android hardware attestation to support multiple alternatives otherwise banned by it. We don't choose what these apps do and would prefer if they entirely removed all of the misguided anti-tampering code and restrictions on what can be used. It still causes problems regularly for apps permitting GrapheneOS since the checks often have bugs or they don't permit newly supported devices promptly.