Discover GNU Taler, the privacy-preserving payment protocol backed by the GNU Project and the NGI Taler initiative. Learn how asymmetric privacy offers buyer anonymity, merchant transparency, and a robust FOSS foundation for regional digital currencies.
It just needs a standard banking API access, so in theory it isn’t much work for banks to integrate. But to be honest I am also not very optimistic that many commercial banks will support it.
Maybe the digital Euro will expose an API that would allow making an easy Taler integration though.