This chapter captures how donations are currently verified and describes the
crucial cryptographic elements used by the Donau. The project is based on
existing cryptography.

\section{How Donations Are Currently Verified}\label{current_system}
In order to find out how the tax authorities nowadays verify donations for
donation deduction an interview with the tax authority Zürich was held.
The interview transcript can be found in the appendix section \ref{transcript}.
Currently the tax authority Zürich verifies donations by hand. The
verification process is intentionally kept simple as donation fraud does not
seem to be a big problem. Other ways to conduct fraud, are more likely and
profitable with less legal risk attached. There is no known data that contains
how much money the state has lost with donation fraud.

If the amount donated is unusually high further proof is needed. The tax
authority will check if the donor is financially capable of donating this
amount. Bank transaction receipts may be requested as proof. In extreme cases
it is brought to court, in which case the donor needs to proof that the
donation is indeed valid and was made by them.

