\section{Conclusion}

It is possible to build a privacy-preserving donation system that
provides reasonably strict assurances for tax authories. While
addressing the complex requirements in this domain with good usability
requires further work and possibly the existence of a suitable eID
infrastructure, the main roadblock is likely the need for tax
authorities to adopt new technology. However, once widely deployed,
such as system would simplify tax filings for donors, contribute to
fair taxation and likely increase charitable donations.
