commit 516adf7e3804025ee58072e78aa733afcf5f99a1
parent f9e72a94603f6a441de889659411cbd33cf18513
Author: Matyja Lukas Adam <lukas.matyja@students.bfh.ch>
Date: Sat, 11 May 2024 15:54:30 +0200
adapt intro
Diffstat:
5 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/doc/thesis/chapters/crypto/crypto.tex b/doc/thesis/chapters/crypto/crypto.tex
@@ -1 +1,3 @@
-\section{blinded signatures}
+\section{Blinded Signatures}
+\subsection{RSA Blind Signature Scheme}
+\subsection{Clause Blind Schnorr Signature Scheme}
diff --git a/doc/thesis/chapters/intro/abstract.tex b/doc/thesis/chapters/intro/abstract.tex
@@ -1,6 +1,6 @@
\begin{abstract}
This bachelor thesis describes and implements a theoretical concept of a donation authority system. The donation authority (Donau) is free software with a focus on privacy and anonymity and part of the GNU Taler project. It depends on the code of the GNU Taler environment, but is completely independent of the Taler payment system. An interview with a local tax authority was held to determine the current state of how donations are verified as well as the usability and possible adoption of a system like the Donau.
-The Donau is operated by the tax authority and maintains a list of verified non-profit charities. The charities as well as the donors must be able to communicate with each other for the system to work. Upon making a donation to one of the charities the donor receives a so called "Donation receipt" which will be stored locally on the donor's device. Throughout this process neither the charity nor the Donau will optain any identifiable information thus making it anonymous. To make the donations tax deductable the donor needs to submit ther receipts to the Donau. Which in turn will combine the receipts in one final receipt called the "Donation statement". Upon request this will be sent to the donor in form of a QR-Code. This QR-Code can then be sent to the tax authority which verifies its validity and is then able to deduct the amount from the taxes.
+The Donau is operated by the tax authority and maintains a list of verified non-profit charities. The charities as well as the donors must be able to communicate with each other for the system to work. Upon making a donation to one of the charities the donor receives a so called "donation receipt" which will be stored locally on the donor's device. Throughout this process neither the charity nor the Donau will optain any identifiable information thus making it anonymous. To make the donations tax deductable the donor needs to submit their receipts to the Donau which will combine the receipts in one final receipt called the "donation statement". Upon request the Donation Statement can be sent in to the tax auditors who verify its validity and are then able to deduct the amount from the taxes.
\end{abstract}
diff --git a/doc/thesis/chapters/intro/introduction.tex b/doc/thesis/chapters/intro/introduction.tex
@@ -1,12 +1,12 @@
\section{Motivation}
-To anonymously donate to a charity and have that donation be deducted from taxes is often not possible. Large enough donations done anonymously using cash may need to be verified (if requested) when attempting to deduct the donation from taxes. The donor would then have to present some sort of evidence in form of a receipt which would deanonymize his donation to the charity. Furthermore, this process can be time consuming, involving a disproportionate amount of effort for the tax authorities.
+Donations can often be deducted from taxes. To do so, the donor may need to present some sort of evidence in form of a receipt. Donations receipts are often sensitive data, which may not want to be shared. To anonymously donate to a charity and bind the donation to the donor for tax deduction is not possible. Furthermore, the process of checking receipts can be time consuming and involves a disproportionate amount of effort for the tax authorities. It can also be annoying for donor, which have to find all the donation receipts of the year when the tax return is made.
\section{Goals}
The aim of this bachelor thesis is to assess the current situation in the area of donation deduction and to formulate and implement a solution for the problems described above. The main goals are the following:
\begin{itemize}
\item The Donau should enable donors to donate anonymously and still be able to deduct the amount from the taxes.
- \item These donations should be verfiable by simply scanning a QR-Code
+ \item These donations should be verfiable by simply scanning a QR-Code.
\item Great usability for both the donor and tax authorities to make the process as easy as possible.
- \item Eliminate tax fraud with donations that where not actually made
+ \item Eliminate tax fraud with fake, expired or third-party donations.
\end{itemize}
diff --git a/doc/thesis/chapters/overview/overview.tex b/doc/thesis/chapters/overview/overview.tex
@@ -7,25 +7,25 @@ The Donau\footnote{short for donation authority} environment includes three stak
\node (image) at (0,0) {\includegraphics[width=0.1\textwidth]{stickman}};
\node at (0,-1.8) {Donor};
%arrow
- \draw [-latex] (1,0) -- (7,0);
+ \draw (1,0) -- (7,0);
%charity
\node (image) at (8.5,0) {\includegraphics[width=0.15\textwidth]{charity}};
\node at (8.5,-1.1) {Charity};
%arrow
- \draw [-latex] (7,-1) -- (5,-2.5);
+ \draw (7,-1) -- (5,-2.5);
%server
\node (image) at (4,-3) {
\includegraphics[width=0.12\textwidth]{tax-authority}};
\node at (4,-4.1) {Tax Authority};
%arrow
- \draw [-latex] (1,-1) -- (3,-2.5);
+ \draw (1,-1) -- (3,-2.5);
\end{tikzpicture}
\end{center}
\caption{stakeholders} \label{fig:stakeholders}
\end{figure}
\subsection{Issuing Donation Receipts}
-When donating to a charity the donor sends the payment together with a receipt request to the charity. In order to link the donation to the donor so that the donation receipt cannot be used by someone else, the donor's unique tax identification number is part of the receipt request. The tax id number does not cause a problem for anonymity as the hole receipt with the id number is blinded (see section 2.x). In the picture \ref{fig:issue receipt request} \pageref{fig:issue receipt request} the blinded receipt is illustrated as envelope. The charity must verify if the payment was successful and if the amount written in the receipt request is lower or equal the amount donated. Next, if the charity approves the receipt request, it signs the untouched request and forwards the request to the Donau. The Donau accepts only issue requests from verified charities. If this is the case, the Donau issues the actual donation receipt by signing the request. This is different from the current model where the charity issues the receipt. By shifting this task to the Donau the receipts can easily be verified and unlinks the donor from the charity which in turn provides anonymity for the donor opposite the Donau in this first step of issuing receipts.
+When donating to a charity the donor sends the payment together with a receipt request to the charity. In order to link the donation to the donor so that the donation receipt cannot be used by someone else, the donor's unique tax identification number is part of the receipt request. The tax id number does not cause a problem for anonymity as the hole receipt with the id number is blinded (see section 2.x). In the picture \ref{fig:issue receipt request} \pageref{fig:issue receipt request} the blinded receipt is illustrated as an envelope. The charity must verify if the payment was successful and if the amount written in the receipt request is lower or equal the amount donated. Next, if the charity approves the receipt request, it signs the untouched request and forwards the request to the Donau. The Donau accepts only issue requests from verified charities. If this is the case, the Donau issues the actual donation receipt by signing the request. This is different from the current model where the charity issues the receipt. By shifting this task to the Donau, the receipts can easily be verified and unlinks the donor from the charity. Because the Donau does only know the amount and the charity it is signing for, this first step of issuing receipts provides anonymity for the donor opposite the Donau (and depending on how it was paid, also opposite the charity).
\begin{figure}[ht]
\begin{center}
@@ -48,7 +48,7 @@ When donating to a charity the donor sends the payment together with a receipt r
\caption{issue receipt request} \label{fig:issue receipt request}
\end{figure}
-Upon receiving the signed issue request from the charity, the Donau must verify the charity signature and check for any legal restrictions, such as a yearly donation limit \textbf{source!}. After successful verification the Donau creates a blinded donation receipt which is sent via charity to the Donor (see figure: \ref{fig:issue receipt response} \pageref{fig:issue receipt response}). The donor now unblinds the signature from the Donau to make it valid for the unblinded receipt (see section 2.x). The unblinded receipt gets saved on the donors device for later. This process repeats for every donation. At the end of the year the donor may have accumulated a bunch of these donation receipts.
+Upon receiving the signed issue request from the charity, the Donau must verify the charity signature and checks that the yearly donation limit of a chairty is not exceeded. After successful verification the Donau creates a blinded donation receipt which is sent via charity to the Donor (see figure: \ref{fig:issue receipt response} \pageref{fig:issue receipt response}). The donor now unblinds the signature from the Donau to make it valid for the unblinded receipt (see section 2.x). The unblinded receipt gets saved on the donors device for later. This process repeats for every donation. At the end of the year the donor may have accumulated a bunch of these donation receipts.
\begin{figure}[ht]
\begin{center}
@@ -72,23 +72,23 @@ Upon receiving the signed issue request from the charity, the Donau must verify
\end{figure}
\subsection{Summarize the Receipts}
-When it is time for the tax declaration (usually at the beginning of the next year) the donor has to request a final donation statement signature from the Donau, summarizing all the donation receipts of a year (see figure: \ref{fig:summarize receipts} \pageref{fig:summarize receipts}). This step combines the amounts of the donation receipts in a single total amount. This protects the privacy of the donor because the individual donation amounts could be enough information to link with specific donations. The combination of the donation receipts makes it also easier for the manual verification besides the tax auditors. The statement signature is made besides the total amount, over the year and the tax id. The donation statement can be requested multiple times during the year for save keeping the donation receipts. The latest donation statement will always contain all the receipts of a year - the old receipts (from a previous statement) and the new donation receipts.
+When it is time for the tax declaration (usually at the beginning of the next year) the donor has to request a final donation statement signature from the Donau, summarizing all the donation receipts of a year (see figure: \ref{fig:summarize receipts} \pageref{fig:summarize receipts}). This step combines the amounts of the donation receipts in a single total amount. This protects the privacy of the donor because the individual donation amounts could be enough information to link with specific donations. Merging donation receipts reduces the time and effort for the manual verification of the tax auditors. The statement signature is made besides the total amount, over the year and the tax id. The donation statement can be requested multiple times during the year for save keeping the donation receipts. The latest donation statement will always contain all the receipts of a year - the old receipts (from a previous statement) and the new donation receipts.
\begin{figure}[ht]
\begin{center}
\begin{tikzpicture}
\node (image) at (0,0) {\includegraphics[width=0.1\textwidth]{stickman}};
%receipt
- \node[rectangle, text width=1.5cm, align=center,font=\tiny, draw=black!80, thick, inner sep=2pt, fill=white] at (3,0.9) {AHVN13: 7560001010000};
+ \node[rectangle, text width=1.65cm, align=center,font=\tiny, draw=black!80, thick, inner sep=2pt, fill=white] at (3,0.9) {AHVN13: 7560001010000};
\node (image) at (3,0.9) {\includegraphics[width=0.04\textwidth]{red_wax}};
\node at (3,0.9) {\small{9}};
%receipt
- \node[rectangle, text width=1.5cm, align=center,font=\tiny, draw=black!80, thick, inner
+ \node[rectangle, text width=1.65cm, align=center,font=\tiny, draw=black!80, thick, inner
sep=2pt, fill=white] at (4,0.8) {AHVN13: 7560001010000};
\node (image) at (4,0.8) {\includegraphics[width=0.04\textwidth]{red_wax}};
\node at (4,0.8) {\small{1}};
%receipt
- \node[rectangle, text width=1.5cm, align=center,font=\tiny, draw=black!80, thick, inner
+ \node[rectangle, text width=1.65cm, align=center,font=\tiny, draw=black!80, thick, inner
sep=2pt, fill=white] at (5,0.7) {AHVN13: 7560001010000};
\node (image) at (5,0.7) {\includegraphics[width=0.04\textwidth]{red_wax}};
\node at (5,0.7) {\small{5}};
@@ -138,6 +138,6 @@ The tax auditors will not have any information to what charity the donor has don
\subsection{Incorporating the Donau}
-Every donor is related to only one specific Donau of his location where he is able to issue and submit donation receipts for deducting taxes. If a charity wants to be accepted in the multiple tax areas, it has to be registered by all the corresponding Donaus. To do so, the charities has to apply to the tax authority. The region for which a Donau responsible depends on the tax area of the tax authority and their reglementation of what is charitable. A Donau is maybe responsible for a geographical area like a canton, a country or even a confederation of states. Different Donaus must also be kept for different currencies, but this should not be a problem as most countries have a single currency.
+Every donor is related to only one specific Donau of his location where he is able to issue and submit donation receipts for deducting taxes. If a charity wants to be accepted in the multiple tax areas, it has to be registered by all the corresponding Donaus. To do so, the charities has to apply to the tax authorities. The region for which a Donau is responsible depends on the tax area of the tax authority and their reglementation of what is charitable. A Donau is maybe responsible for a geographical area like a canton, a country or even a confederation of states. Different Donaus must also be kept for different currencies, but this should not be a problem as most countries have a single currency.
diff --git a/doc/thesis/thesis.pdf b/doc/thesis/thesis.pdf
Binary files differ.
