proc doc

19 files changed, 1065 insertions, 0 deletions

diff --git a/doc/flows/Makefile b/doc/flows/Makefile
new file mode 100644
index 000000000..e6af0897c
--- /dev/null
+++ b/doc/flows/Makefile
@@ -0,0 +1,3 @@
+all:
+	pdflatex main.tex
+	pdflatex main.tex
diff --git a/doc/flows/fees-coins.tex b/doc/flows/fees-coins.tex
new file mode 100644
index 000000000..c24f19a28
--- /dev/null
+++ b/doc/flows/fees-coins.tex
@@ -0,0 +1,39 @@
+\section{Fees per coin} \label{sec:fees:coin}
+
+Payments with Taler are always made using coins.  Each coin has a specific
+denomination, and an exchange will issue coins in different denominations (in
+the same currency).  The fees per coin depend on the operation and the
+denomination.
+
+The primary fee to be paid is a {\bf deposit} fee that is
+charged whenever a coin is fully or partially deposited
+into a bank account or another wallet.
+
+A secondary fee to be paid is a {\bf change} fee that is
+charged whenever a coin partially spent and change must
+be rendered.
+
+Coins also have an {\bf expiration} date of approximately {\bf one year}.
+After the expiration date, coins become worthless.  Wallets that are online
+{\bf three months} {\em before} a coin expires will automatically trade any
+such coins for one or more fresh coins with a later expiration date. This
+process is also subject to the {\bf change} fee.
+
+
+\begin{table}[h!]
+  \caption{Fees per coin. Coin denomination values are given in units of CHF 0.01.}
+  \label{table:fees:coins}
+  \begin{center}
+    \begin{tabular}{l|c|r}
+      {\bf Denomination} & {\bf Fee type} & {\bf Amount}   \\ \hline \hline
+     $2^{-4}-2^{ 0}$      & deposit        & {\em CHF 0.00125} \\
+     $2^{-4}-2^{ 0}$      & change         & {\em CHF 0.00125} \\
+     $2^{ 0}-2^{ 3}$      & deposit        & {\em CHF 0.00250} \\
+     $2^{ 0}-2^{ 3}$      & change         & {\em CHF 0.00125} \\
+     $2^{ 4}-2^{ 8}$      & deposit        & {\em CHF 0.005} \\
+     $2^{ 4}-2^{ 8}$      & change         & {\em CHF 0.00125} \\
+     $2^{ 8}-2^{12}$      & deposit        & {\em CHF 0.01} \\
+     $2^{ 8}-2^{12}$      & change         & {\em CHF 0.00125} \\
+    \end{tabular}
+  \end{center}
+\end{table}
diff --git a/doc/flows/fees-wire.tex b/doc/flows/fees-wire.tex
new file mode 100644
index 000000000..214a69021
--- /dev/null
+++ b/doc/flows/fees-wire.tex
@@ -0,0 +1,30 @@
+\section{Fees per wire} \label{sec:fees:wire}
+
+Wire fees apply whenever an exchange needs to initiate a wire transfer to
+another bank account.  Wire fees do not apply to every individual payment to a
+merchant, as merchants can choose to {\em aggregate} multiple micropayments
+into one large payment on the wire.  Wire fees also do not apply to
+wallet-to-wallet payments within the Taler system.
+
+A {\bf wire} fee is applied when a merchant receives
+an aggregated payment into their bank account.
+
+A {\bf closing} fee is applied when a wallet fails to
+withdraw coins and money has to be sent back to the
+originating bank account.
+
+\begin{table}[h!]
+  \caption{Table with wire fees. Wire fees are set annually.}
+  \label{table:fees:wire}
+  \begin{center}
+    \begin{tabular}{l|c|r}
+      {\bf Year} & {\bf Fee type} & {\bf Amount}   \\ \hline \hline
+      2023       & wire           & {\em CHF 0.05} \\
+      2023       & closing        & {\em CHF 0.10} \\
+      2024       & wire           & {\em CHF 0.05} \\
+      2024       & closing        & {\em CHF 0.10} \\
+      2025       & wire           & {\em CHF 0.05} \\
+      2025       & closing        & {\em CHF 0.10} \\
+  \end{tabular}
+  \end{center}
+\end{table}
diff --git a/doc/flows/int-deposit.tex b/doc/flows/int-deposit.tex
new file mode 100644
index 000000000..4b1f657ba
--- /dev/null
+++ b/doc/flows/int-deposit.tex
@@ -0,0 +1,52 @@
+\section{Deposit}
+
+
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer wallet \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{bank}{\shortstack{Customer bank \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] {Checking \\ Accounts};
+      \end{tikzpicture}
+    }}
+    \postlevel
+    \begin{callself}{wallet}{Review deposit fees}{}
+    \end{callself}
+    \mess[0]{wallet}{Deposit {(Coins)}}{exchange}
+    \begin{sdblock}{Acceptable account?}{}
+    \mess[0]{exchange}{{Refuse deposit}}{wallet}
+    \end{sdblock}
+    \begin{sdblock}{KYC/AML required?}{}
+    \begin{callself}{exchange}{Figures~\ref{fig:proc:kyc}, \ref{fig:proc:aml}}{}
+    \end{callself}
+    \end{sdblock}
+%    \prelevel
+%    \prelevel
+%    \begin{sdblock}{User abort?}{}
+%    \mess[0]{wallet}{{Request abort}}{exchange}
+%    \mess[0]{exchange}{{Abort confirmation}}{wallet}
+%    \end{sdblock}
+    \mess[0]{exchange}{{Initiate transfer}}{bank}
+
+\end{sequencediagram}
+  \caption{Deposit interactions between customer, Taler exchange (payment
+    service provider) and customer's bank.}
+  \label{fig:int:deposit}
+\end{figure}
+
+We do {\bf not} permit the customer to regain control over their funds {\em
+  unless} they pass the KYC/AML checks. The technical reason is simply that
+the KYC/AML checks happen {\em after} the aggregation logic and at this point
+refunds are no longer permitted.  From a compliance perspective, this also
+prevents malicious customers from risk-free probing of the system.
diff --git a/doc/flows/int-pay.tex b/doc/flows/int-pay.tex
new file mode 100644
index 000000000..d2f0fb585
--- /dev/null
+++ b/doc/flows/int-pay.tex
@@ -0,0 +1,58 @@
+\section{Pay}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer wallet \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \newinst[1]{merchant}{\shortstack{Merchant \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[1]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[1]{bank}{\shortstack{Merchant bank \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] {Commercial \\ Accounts};
+      \end{tikzpicture}
+    }}
+    \postlevel
+    \mess[0]{wallet}{Browse catalog}{merchant}
+    \mess[0]{merchant}{Commercial offer}{wallet}
+    \begin{callself}{wallet}{Review offer}{}
+    \end{callself}
+    \mess[0]{wallet}{Send payment {(Coins)}}{merchant}
+    \mess[0]{merchant}{Deposit {(Coins)}}{exchange}
+    \begin{sdblock}{Acceptable account?}{}
+    \mess[0]{exchange}{{Refuse deposit}}{merchant}
+    \mess[0]{merchant}{{Refund purchase}}{wallet}
+    \end{sdblock}
+    \mess[0]{exchange}{{Confirm deposit}}{merchant}
+    \mess[0]{merchant}{Fulfill order}{wallet}
+    \begin{callself}{exchange}{Aggregate transactions}{}
+    \end{callself}
+    \begin{sdblock}{KYC/AML required?}{}
+    \begin{callself}{exchange}{Figures~\ref{fig:proc:kyc}, \ref{fig:proc:aml}}{}
+    \end{callself}
+    \end{sdblock}
+    \mess[0]{exchange}{{Initiate transfer}}{bank}
+  \end{sequencediagram}
+  \caption{Deposit interactions between customer, merchant,
+    Taler exchange (payment service provider) and merchant bank.}
+  \label{fig:int:pay}
+\end{figure}
+
+{\bf Internal note:} The exchange refusing a deposit immediately based on
+unaccaptable merchant accounts may not be fully implemented (this is a very
+recent feature, after all); especially the merchant then automatically
+refunding the purchase to the customer is certainly missing.  However,
+the entire situation only arises when a merchant is incorrectly configured
+and in violation of the terms of service.
diff --git a/doc/flows/int-pull.tex b/doc/flows/int-pull.tex
new file mode 100644
index 000000000..8c9b66b1b
--- /dev/null
+++ b/doc/flows/int-pull.tex
@@ -0,0 +1,55 @@
+\section{Pull payment (aka invoicing)}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{payer}{\shortstack{Payer \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] {Pre-funded \\ Wallet};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{payee}{\shortstack{Payee \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \postlevel
+    \begin{callself}{payee}{Review pull payment fees}{}
+    \end{callself}
+    \mess[0]{payee}{{Create invoice (Wallet ID)}}{exchange}
+
+    \mess[0]{exchange}{{Invoice ready}}{payee}
+    \mess[0]{payee}{{Send invoice (e.g. via QR code)}}{payer}
+
+    \begin{callself}{payer}{Review invoice}{}
+    \end{callself}
+    \mess[0]{payer}{{Make payment (Coins)}}{exchange}
+
+    \begin{sdblock}{Domestic wallet?}{}
+    \begin{callself}{exchange}{Figure~\ref{fig:proc:domestic}}{}
+    \end{callself}
+    \end{sdblock}
+    \begin{sdblock}{KYC/AML required?}{}
+    \begin{callself}{exchange}{Figures~\ref{fig:proc:kyc}, \ref{fig:proc:aml}}{}
+    \end{callself}
+    \end{sdblock}
+
+    \mess[0]{exchange}{{Distribute digital cash}}{payee}
+
+\end{sequencediagram}
+  \caption{Interactions between wallets and Taler exchange
+    in a pull payment.}
+  \label{fig:int:pull}
+\end{figure}
+
+We do {\bf not} permit the payer to regain control over their funds, once the
+payment was made they are locked {\em until} the payee passes the KYC/AML
+checks.  We only do the AML/KYC process once the funds are locked at the
+exchange. This ensures we know the actual transacted amounts (which may be
+lower than the total amounts requested) and prevents risk-free probing
+attacks.
diff --git a/doc/flows/int-push.tex b/doc/flows/int-push.tex
new file mode 100644
index 000000000..fd49e8d40
--- /dev/null
+++ b/doc/flows/int-push.tex
@@ -0,0 +1,47 @@
+\section{Push payment}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{payer}{\shortstack{Payer \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] {Pre-funded \\ Wallet};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{payee}{\shortstack{Payee \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \postlevel
+    \begin{callself}{payer}{Review push payment fees}{}
+    \end{callself}
+    \mess[0]{payer}{{Push funds (Coins)}}{exchange}
+    \mess[0]{payer}{{Offer payment (e.g. via QR code)}}{payee}
+    \begin{callself}{payee}{Review payment offer}{}
+    \end{callself}
+    \mess[0]{payee}{{Request funds (Wallet ID)}}{exchange}
+    \begin{sdblock}{Domestic wallet?}{}
+    \begin{callself}{exchange}{Figure~\ref{fig:proc:domestic}}{}
+    \end{callself}
+    \end{sdblock}
+    \begin{sdblock}{KYC/AML required?}{}
+    \begin{callself}{exchange}{Figures~\ref{fig:proc:kyc}, \ref{fig:proc:aml}}{}
+    \end{callself}
+    \end{sdblock}
+    \mess[0]{exchange}{{Distribute digital cash}}{payee}
+%    \postlevel
+    \begin{sdblock}{Payment offer expired?}{}
+    \mess[0]{exchange}{{Return funds}}{payer}
+    \end{sdblock}
+
+\end{sequencediagram}
+  \caption{Interactions between wallets and Taler exchange
+    in a push payment.}
+  \label{fig:int:push}
+\end{figure}
diff --git a/doc/flows/int-refund.tex b/doc/flows/int-refund.tex
new file mode 100644
index 000000000..351ecda2b
--- /dev/null
+++ b/doc/flows/int-refund.tex
@@ -0,0 +1,39 @@
+\section{Refund}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer wallet \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{merchant}{\shortstack{Merchant \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \postlevel
+    \begin{callself}{merchant}{Initiate refund}{}
+    \end{callself}
+    \mess[0]{merchant}{{Refund offer (QR code)}}{wallet}
+    \mess[0]{wallet}{Request refund}{merchant}
+    \mess[0]{merchant}{Approve refund}{exchange}
+    \mess[0]{exchange}{Confirm refund}{merchant}
+    \mess[0]{merchant}{Return refund confirmation}{wallet}
+  \end{sequencediagram}
+  \caption{Refund processing when a merchant is unable to fulfill
+    a contract.  Refunds must happen {\em before} the
+    exchange has aggregated the original transaction for
+    a bank transfer to the merchant. Furthermore, refunds
+    can only go to the customer who made the original payment
+    and the refund cannot exceed the amount of the original
+    payment.}
+  \label{fig:int:refund}
+\end{figure}
diff --git a/doc/flows/int-shutdown.tex b/doc/flows/int-shutdown.tex
new file mode 100644
index 000000000..e8ee6feed
--- /dev/null
+++ b/doc/flows/int-shutdown.tex
@@ -0,0 +1,48 @@
+\section{Shutdown}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer wallet \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{bank}{\shortstack{Customer bank \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] {Checking \\ Accounts};
+      \end{tikzpicture}
+    }}
+    \postlevel
+
+    \begin{callself}{exchange}{Operator initiates shutdown}{}
+    \end{callself}
+     \mess[0]{exchange}{{Shutdown alert}}{wallet}
+     \begin{sdblock}{Bank account known?}{}
+       \begin{callself}{wallet}{Designate bank account}{}
+       \end{callself}
+     \end{sdblock}
+    \mess[0]{wallet}{{Deposit (Coins)}}{exchange}
+    \begin{sdblock}{Acceptable account?}{}
+    \mess[0]{exchange}{{Refuse deposit}}{wallet}
+    \end{sdblock}
+    \begin{sdblock}{KYC/AML required?}{}
+    \begin{callself}{exchange}{Figures~\ref{fig:proc:kyc}, \ref{fig:proc:aml}}{}
+    \end{callself}
+    \end{sdblock}
+    \mess[0]{exchange}{{Initiate transfer}}{bank}
+\end{sequencediagram}
+  \caption{Shutdown interactions between customer, Taler exchange (payment
+    service provider) and bank.}
+  \label{fig:int:shutdown}
+\end{figure}
+
+KYC/AML requirements are relaxed in cases where the customer is able to
+cryptographically demonstrate that they previously withdrew these coins from
+the designated checking account.  Thus, KYC/AML checks here primarily still
+apply if the customer received the funds via P2P transfers from other wallets.
diff --git a/doc/flows/int-withdraw.tex b/doc/flows/int-withdraw.tex
new file mode 100644
index 000000000..9b044df67
--- /dev/null
+++ b/doc/flows/int-withdraw.tex
@@ -0,0 +1,49 @@
+\section{Withdraw}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer wallet \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{bank}{\shortstack{Customer bank \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] {Checking \\ Accounts};
+      \end{tikzpicture}
+    }}
+    \postlevel
+    \mess[0]{wallet}{Withdraw {(Amount)}}{exchange}
+   \mess[0]{exchange}{{Configuration (ToS, Fees)}}{wallet}
+    \begin{sdblock}{once}{}
+      \begin{callself}{wallet}{Accept ToS}{}
+      \end{callself}
+    \end{sdblock}
+    \begin{callself}{wallet}{Review withdraw fees}{}
+    \end{callself}
+    \mess[0]{wallet}{{Initiate transfer (Amount, Credit account, Wallet ID)}}{bank}
+    \mess[0]{bank}{{Credit (Wallet ID)}}{exchange}
+
+    \begin{sdblock}{Acceptable transfer?}{}
+    \mess[0]{exchange}{{Bounce funds}}{bank}
+    \end{sdblock}
+    \postlevel
+    \mess[0]{exchange}{Confirm wire transfer}{wallet}
+    \mess[0]{wallet}{Request digital cash}{exchange}
+    \mess[0]{exchange}{Distribute digital cash}{wallet}
+    \postlevel
+    \begin{sdblock}{Withdraw period expired?}{}
+    \mess[0]{exchange}{{Return remaining funds}}{bank}
+    \end{sdblock}
+\end{sequencediagram}
+  \caption{Withdraw interactions between customer, Taler exchange (payment
+    service provider) and bank.  The amount of digital cash distributed is
+    subject to limits per origin account (see Figure~\ref{fig:kyc:withdraw}).}
+  \label{fig:int:withdraw}
+\end{figure}
diff --git a/doc/flows/kyc-balance.tex b/doc/flows/kyc-balance.tex
new file mode 100644
index 000000000..1192021b3
--- /dev/null
+++ b/doc/flows/kyc-balance.tex
@@ -0,0 +1,57 @@
+\section{KYC: Balance}
+
+Note: this process is not implemented and would require non-trivial extra work
+if required.
+
+\begin{figure}[h!]
+  \begin{center}
+\begin{tikzpicture}[node distance=1cm,font=\sffamily,
+    start/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=yellow!30},
+    end/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30},
+    process/.style={rectangle, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=orange!30},
+    failed/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=red!30},
+    io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
+    decision/.style={diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30},
+    arr/.style={very thick,-latex},
+    every edge quotes/.style = {auto, font=\footnotesize, sloped}
+    ]
+ \node (start) [start] {Start};
+ \node (balance) [decision,below=of start,text width=3cm] {Transaction leaves wallet balance below AML threshold?};
+ \node (registered) [decision,below=of balance,text width=3cm] {Wallet has been subject to KYC?};
+ \node (kyc) [process, below=of registered] {KYC process};
+ \node (aml) [process, left=of kyc] {AML process};
+ \node (allow) [end, right=of balance] {Allow};
+ \node (deny) [failed, right=of registered] {Deny};
+ \draw[arr] (start) -> (balance) {};
+ \draw[arr] (balance) -> (registered);
+ \draw (balance) edge["No"] (registered);
+ \draw[arr] (balance) -> (allow);
+ \draw (balance) edge["Yes"] (allow);
+
+ \draw[arr] (registered) -> (kyc);
+ \draw (registered) edge["No"] (kyc);
+ \draw[arr] (registered) -> (deny);
+ \draw (registered) edge["Yes"] (deny);
+
+ \draw[arr] (kyc) -> (deny);
+ \draw (kyc) edge["Failed"] (deny);
+ \draw[arr] (kyc) -> (aml);
+ \draw (kyc) edge["Ok"] (aml);
+
+ \draw[arr] (aml) -> (balance.west);
+ \draw (aml) edge["New threshold"] (balance.west);
+\end{tikzpicture}
+  \end{center}
+  \caption{Regulatory process when a wallet exceeds its AML threshold.
+    When the transfer is denied the transaction (withdraw, P2P transfer)
+    is refused by the wallet.}
+\end{figure}
+
+
+\begin{table}[h!]
+  \caption{Settings for the balance trigger}
+  \begin{tabular}{l|l|r}
+    {\bf Setting}          & {\bf Type}         & {\bf Value} \\ \hline \hline
+    Default AML threshold  & Amount             & {\em 1000 CHF} \\
+  \end{tabular}
+\end{table}
diff --git a/doc/flows/kyc-deposit.tex b/doc/flows/kyc-deposit.tex
new file mode 100644
index 000000000..2423235ab
--- /dev/null
+++ b/doc/flows/kyc-deposit.tex
@@ -0,0 +1,71 @@
+\section{KYC: Deposit}
+
+\begin{figure}[h!]
+  \begin{center}
+\begin{tikzpicture}[node distance=1cm,font=\sffamily,
+    start/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=yellow!30},
+    end/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30},
+    process/.style={rectangle, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=orange!30},
+    failed/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=red!30},
+    io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
+    decision/.style={diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30},
+    arr/.style={very thick,-latex},
+    every edge quotes/.style = {auto, font=\footnotesize, sloped}
+    ]
+ \node (start) [start] {Start};
+ \node (country) [decision,below=of start,text width=2.5cm] {Target account in allowed country?};
+ \node (amount) [decision, below=of country,text width=2.5cm] {Target account received less than KYC threshold?};
+ \node (kyc) [process, right=of amount] {KYC process};
+ \node (high) [decision, below=of amount,text width=2.5cm] {Target account received more than its AML threshold?};
+ \node (aml) [process, right=of high] {AML process};
+ \node (dummy) [below right=of aml] {};
+ \node (allow) [end, below right=of dummy] {Allow};
+ \node (deny) [failed, right=of kyc] {Deny};
+ \draw[arr] (start) -> (country) {};
+
+ \draw[arr] (country) -> (amount);
+ \draw (country) edge["Yes"] (amount);
+
+ \draw[arr] (country.east) -> (deny);
+ \draw (country.east) edge["No"] (deny);
+
+ \draw[arr] (amount) -> (high);
+ \draw (amount) edge["Yes"] (high);
+
+ \draw[arr] (amount.east) -> (kyc);
+ \draw (amount.east) edge["No"] (kyc);
+
+ \draw[arr] (kyc) -> (deny);
+ \draw (kyc) edge["Failed"] (deny);
+
+ \draw[arr] (kyc) -> (high);
+ \draw (kyc) edge["Succeeded"] (high);
+
+ \draw[arr] (high.south) -> (allow);
+ \draw (high.south) edge["Yes"] (allow);
+
+ \draw[arr] (high.east) -> (aml);
+ \draw (high.east) edge["No"] (aml);
+
+ \draw[arr] (aml) -> (deny);
+ \draw (aml) edge["Violation"] (deny);
+
+ \draw[arr] (aml) -> (allow);
+ \draw (aml) edge["Ok"] (allow);
+\end{tikzpicture}
+  \end{center}
+  \caption{Regulatory process when depositing digital cash into a bank
+    account.  When the transfer is denied, the money is returned to the
+    originating wallet.}
+\end{figure}
+
+
+\begin{table}[h!]
+  \caption{Settings for the deposit trigger}
+  \begin{tabular}{l|l|r}
+    {\bf Setting}                 & {\bf Type}         & {\bf Value}    \\ \hline \hline
+    Allowed bank accounts         & RFC 8905 RegEx     & {\em CH*}      \\ \hline
+    KYC deposit threshold         & Amount             & {\em 1000 CHF} \\
+    Default AML deposit threshold & Amount             & {\em 2500 CHF} \\
+  \end{tabular}
+\end{table}
diff --git a/doc/flows/kyc-pull.tex b/doc/flows/kyc-pull.tex
new file mode 100644
index 000000000..b7cd34477
--- /dev/null
+++ b/doc/flows/kyc-pull.tex
@@ -0,0 +1,78 @@
+\section{KYC/AML: Pull Payment}
+
+\begin{figure}[h!]
+  \begin{center}
+\begin{tikzpicture}[node distance=0.9cm,font=\sffamily,
+    start/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=yellow!30},
+    end/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30},
+    process/.style={rectangle, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=orange!30},
+    failed/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=red!30},
+    io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
+    decision/.style={diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30},
+    arr/.style={very thick,-latex},
+    every edge quotes/.style = {auto, font=\footnotesize, sloped}
+    ]
+ \node (start) [start] {Start};
+ \node (wallet) [decision,below=of start,text width=2.5cm] {Wallet linked to (domestic) phone number?};
+ \node (domestic) [process, right=of wallet] {Validate phone number};
+ \node (amount) [decision, below=of wallet,text width=2.5cm] {Wallet received less than KYC threshold from other wallets?};
+ \node (kyc) [process, right=of amount] {KYC process};
+ \node (high) [decision, below=of amount,text width=2.5cm] {Wallet received more than its AML threshold?};
+ \node (aml) [process, right=of high] {AML process};
+ \node (dummy) [below right=of aml] {};
+ \node (allow) [end, below right=of dummy] {Allow invoicing};
+ \node (deny) [failed, right=of kyc] {Deny};
+ \draw[arr] (start) -> (wallet) {};
+
+ \draw[arr] (wallet) -> (amount);
+ \draw (wallet) edge["Yes"] (amount);
+
+ \draw[arr] (wallet.east) -> (domestic);
+ \draw (wallet.east) edge["No"] (domestic);
+
+ \draw[arr] (domestic) -> (amount);
+ \draw (domestic) edge["Confirmed"] (amount);
+
+ \draw[arr] (domestic) -> (deny);
+ \draw (domestic) edge["Failed"] (deny);
+
+ \draw[arr] (amount) -> (high);
+ \draw (amount) edge["Yes"] (high);
+
+ \draw[arr] (amount.east) -> (kyc);
+ \draw (amount.east) edge["No"] (kyc);
+
+ \draw[arr] (kyc) -> (deny);
+ \draw (kyc) edge["Failed"] (deny);
+
+ \draw[arr] (kyc) -> (high);
+ \draw (kyc) edge["Succeeded"] (high);
+
+ \draw[arr] (high.south) -> (allow);
+ \draw (high.south) edge["Yes"] (allow);
+
+ \draw[arr] (high.east) -> (aml);
+ \draw (high.east) edge["No"] (aml);
+
+ \draw[arr] (aml) -> (deny);
+ \draw (aml) edge["Violation"] (deny);
+
+ \draw[arr] (aml) -> (allow);
+ \draw (aml) edge["Ok"] (allow);
+\end{tikzpicture}
+  \end{center}
+  \caption{Regulatory process when receiving payments from another wallet.
+    The threshold depends on the risk profile from the KYC process.
+    When invoicing is denied the wallet cannot generate the invoice.}
+\end{figure}
+
+
+\begin{table}[h!]
+  \caption{Settings for the pull payment trigger}
+  \begin{tabular}{l|l|r}
+    {\bf Setting}             & {\bf Type}      & {\bf Value} \\ \hline \hline
+    Permitted phone numbers   & Dialing prefix  & {\em +41} \\
+    P2P KYC threshold         & Amount          & {\em  100 CHF} \\
+    Default P2P AML threshold & Amount          & {\em 1000 CHF} \\
+  \end{tabular}
+\end{table}
diff --git a/doc/flows/kyc-push.tex b/doc/flows/kyc-push.tex
new file mode 100644
index 000000000..6d25ac7ef
--- /dev/null
+++ b/doc/flows/kyc-push.tex
@@ -0,0 +1,79 @@
+\section{KYC/AML: Push Payment}
+
+\begin{figure}[h!]
+  \begin{center}
+\begin{tikzpicture}[node distance=0.9cm,font=\sffamily,
+    start/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=yellow!30},
+    end/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30},
+    process/.style={rectangle, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=orange!30},
+    failed/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=red!30},
+    io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
+    decision/.style={diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30},
+    arr/.style={very thick,-latex},
+    every edge quotes/.style = {auto, font=\footnotesize, sloped}
+    ]
+ \node (start) [start] {Start};
+ \node (wallet) [decision,below=of start,text width=2.5cm] {Wallet linked to (domestic) phone number?};
+ \node (domestic) [process, right=of wallet] {Validate phone number};
+ \node (amount) [decision, below=of wallet,text width=2.5cm] {Wallet received less than KYC threshold from other wallets?};
+ \node (kyc) [process, right=of amount] {KYC process};
+ \node (high) [decision, below=of amount,text width=2.5cm] {Wallet received more than its AML threshold?};
+ \node (aml) [process, right=of high] {AML process};
+ \node (dummy) [below right=of aml] {};
+ \node (allow) [end, below right=of dummy] {Allow};
+ \node (deny) [failed, right=of kyc] {Deny};
+ \draw[arr] (start) -> (wallet) {};
+
+ \draw[arr] (wallet) -> (amount);
+ \draw (wallet) edge["Yes"] (amount);
+
+ \draw[arr] (wallet.east) -> (domestic);
+ \draw (wallet.east) edge["No"] (domestic);
+
+ \draw[arr] (domestic) -> (amount);
+ \draw (domestic) edge["Confirmed"] (amount);
+
+ \draw[arr] (domestic) -> (deny);
+ \draw (domestic) edge["Failed"] (deny);
+
+ \draw[arr] (amount) -> (high);
+ \draw (amount) edge["Yes"] (high);
+
+ \draw[arr] (amount.east) -> (kyc);
+ \draw (amount.east) edge["No"] (kyc);
+
+ \draw[arr] (kyc) -> (deny);
+ \draw (kyc) edge["Failed"] (deny);
+
+ \draw[arr] (kyc) -> (high);
+ \draw (kyc) edge["Succeeded"] (high);
+
+ \draw[arr] (high.south) -> (allow);
+ \draw (high.south) edge["Yes"] (allow);
+
+ \draw[arr] (high.east) -> (aml);
+ \draw (high.east) edge["No"] (aml);
+
+ \draw[arr] (aml) -> (deny);
+ \draw (aml) edge["Violation"] (deny);
+
+ \draw[arr] (aml) -> (allow);
+ \draw (aml) edge["Ok"] (allow);
+\end{tikzpicture}
+  \end{center}
+  \caption{Regulatory process when receiving payments from another wallet.
+    The threshold depends on the risk profile from the KYC process.
+    When the transfer is denied the money is (eventually) returned to
+    the originating wallet.}
+\end{figure}
+
+
+\begin{table}[h!]
+  \caption{Settings for the push payment trigger}
+  \begin{tabular}{l|l|r}
+    {\bf Setting}             & {\bf Type}     & {\bf Value} \\ \hline \hline
+    Permitted phone numbers   & Dialing prefix & {\em +41} \\
+    P2P KYC threshold         & Amount         & {\em  100 CHF} \\
+    Default P2P AML threshold & Amount         & {\em 1000 CHF} \\
+  \end{tabular}
+\end{table}
diff --git a/doc/flows/kyc-withdraw.tex b/doc/flows/kyc-withdraw.tex
new file mode 100644
index 000000000..ecdc9a399
--- /dev/null
+++ b/doc/flows/kyc-withdraw.tex
@@ -0,0 +1,45 @@
+\section{KYC: Withdraw}
+
+\begin{figure}[h!]
+  \begin{center}
+\begin{tikzpicture}[node distance=1cm,font=\sffamily,
+    start/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=yellow!30},
+    end/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=red!30},
+    process/.style={rectangle, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=orange!30},
+    failed/.style={rectangle, rounded corners, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=red!30},
+    io/.style={trapezium, trapezium left angle=70, trapezium right angle=110, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=blue!30},
+    decision/.style={diamond, minimum width=3cm, minimum height=1cm, text centered, draw=black, fill=green!30},
+    arr/.style={very thick,-latex},
+    every edge quotes/.style = {auto, font=\footnotesize, sloped}
+    ]
+ \node (start) [start] {Start};
+ \node (country) [decision,below=of start,text width=3cm] {Wire transfer originates from allowed country?};
+ \node (amount) [decision, below=of country,text width=3cm] {Transferred less than maximum amount from origin account over last month?};
+ \node (allow) [end, below=of amount] {Allow};
+ \node (deny) [failed, right=of allow] {Deny};
+ \draw[arr] (start) -> (country) {};
+ \draw[arr] (country) -> (amount);
+ \draw (country) edge["Yes"] (amount);
+ \draw[arr] (country.east) -> (deny);
+ \draw (country.east) edge["No"] (deny);
+ \draw[arr] (amount) -> (allow);
+ \draw (amount) edge["Yes"] (allow);
+ \draw[arr] (amount.east) -> (deny);
+ \draw (amount.east) edge["No"] (deny);
+\end{tikzpicture}
+  \end{center}
+  \caption{Regulatory process when withdrawing digital cash from a
+    bank account.
+    When the transfer is denied the money is (eventually) returned to
+    the originating bank account.}
+  \label{fig:kyc:withdraw}
+\end{figure}
+
+\begin{table}[h!]
+  \caption{Settings for the withdraw trigger}
+  \begin{tabular}{l|l|r}
+    {\bf Setting}            & {\bf Type}         & {\bf Value} \\ \hline \hline
+    Allowed bank accounts    & RFC 8905 RegEx     & {\em CH*} \\ \hline
+    Monthly withdraw maximum & Amount             & {\em 1000 CHF} \\
+  \end{tabular}
+\end{table}
diff --git a/doc/flows/main.tex b/doc/flows/main.tex
new file mode 100644
index 000000000..c2aee65ac
--- /dev/null
+++ b/doc/flows/main.tex
@@ -0,0 +1,159 @@
+\documentclass[10pt,a4paper,oneside]{book}
+\usepackage[utf8]{inputenc}
+\usepackage{url}
+\usepackage{graphicx}
+\usepackage{hyperref}
+\usepackage{qrcode}
+\usepackage{pgf-umlsd}
+\usepackage{tikz}
+\usetikzlibrary{shapes,arrows}
+\usetikzlibrary{positioning}
+\usetikzlibrary{calc}
+\usetikzlibrary{quotes}
+\author{Christian Grothoff}
+\title{Flows in the GNU Taler System}
+
+\begin{document}
+
+\tableofcontents
+
+\chapter{Interactions} \label{chap:interactions}
+
+This chapter introduces the main payment interactions in the GNU Taler payment
+system. For each interaction, we introduce the parties involved and in which
+order they interact and how.  In each interaction it is possible that the
+Taler exchange needs to trigger a compliance process.  These regulatory
+riggers are described in more detail in Chapter~\ref{chap:triggers}.
+
+The main interactions of the system are:
+
+\begin{description}
+  \item[withdraw] a customer withdraws digital cash to their wallet
+  \item[deposit] a customer returns digital cash into their bank account
+  \item[pay] a customer pays into bank account of a merchant
+  \item[refund] a merchant decides to return funds to a customer
+  \item[push] a customer sends a payment to another wallet
+  \item[pull] a customer requests a payment from another wallet (effectively sending an invoice)
+  \item[shutdown] the Taler payment system operator informs the customers that the system is being shut down for good
+\end{description}
+
+Taler has no accounts (this is digital cash) and thus there is no ``opening''
+or ``closing'' of accounts. The equivalent of ``opening'' an account is thus
+to withdraw digital cash.  The equivalent of ``closing'' an account is to
+either (1) deposit the funds explicitly into a bank account, or (2) the coins
+will expire if the wallet was lost (including long-term offline or
+uninstalled).  Finally, if a wallet remains (occasionally) online but a user
+does simply not spend the coins will (3) diminish in value from the change
+fees (see Section~\ref{sec:fees:coin}) that apply to prevent the coins from
+expiring outright.
+
+The following sections describe the respective processes for each of these
+interactions.
+
+\include{int-withdraw}
+\include{int-deposit}
+\include{int-pay}
+\include{int-refund}
+\include{int-push}
+\include{int-pull}
+\include{int-shutdown}
+
+
+\chapter{Regulatory Triggers} \label{chap:triggers}
+
+In this chapter we show decision diagrams for regulatory processes of the
+various core operations of the GNU Taler payment system.  In each case, the
+{\bf start} state refers to one of the interactions described in the previous
+chapter.  The payment system will then use the process to arrive at an {\bf
+  allow} decision which permits the transaction to go through, or at a {\bf
+  deny} decision which ensures that the funds are not moved.
+
+The specific {\em decisions} (in green) depend on the risk profile and the
+regulatory environment. The tables in each section list the specific values
+that are to be configured.
+
+There are five types if interactions that can trigger regulatory processes:
+
+\begin{description}
+  \item[withdraw] a customer withdraws digital cash from their {\bf bank account}
+  \item[deposit] a merchant's {\bf bank account} is designated to receive a payment in digital cash
+  \item[push] a {\bf wallet} accepts a payment from another wallet
+  \item[pull] a {\bf wallet} requests a payment from another wallet
+  \item[balance] a withdraw or P2P payment causes the balance of a {\bf wallet} to exceed a given threshold
+\end{description}
+
+We note in bold the {\bf anchor} for the regulator process. The anchor is used
+to link the interaction to an identity.  Once an identity has been established
+for a particular anchor, that link is considered established for all types of
+activities involving that anchor.  A wallet is uniquely identified in the
+system by its unique cryptographic key.  A bank account is uniquely identified
+in the system by its (RFC 8905) bank routing data (usually including BIC, IBAN
+and account owner name).
+
+The KYC and AML processes themselves are described in
+Chapter~\ref{chap:regproc}.
+
+\include{kyc-withdraw}
+\include{kyc-deposit}
+\include{kyc-push}
+\include{kyc-pull}
+\include{kyc-balance}
+
+\chapter{Regulatory Processes} \label{chap:regproc}
+
+This chapter describes the interactions between the customer, exchange and
+organizations or staff assisting with regulatory processes designed to ensure
+that customers are residents in the area of operation of the payment service
+provider, are properly identified, and do not engage in money laundering.
+
+The three main regulatory processes are:
+
+\begin{description}
+\item[domestic check] This process establishes that a user is generally
+  eligible to use the payment system.  The process checks that the user has an
+  eligible address, but stops short of establishing the user's identity.
+\item[kyc] This process establishes a user's legal identity, possibly
+  using external providers to review documents and check against blacklists.
+\item[aml] The AML process reviews suspicious payment activities for
+  money laundering. Here AML staff reviews all collected information.
+\end{description}
+
+\include{proc-domestic}
+\include{proc-kyc}
+\include{proc-aml}
+
+\chapter{Fees} \label{chap:fees}
+
+The business model for operating a Taler exchange is to charge transaction
+fees.  Fees are charged on certain operations by the exchange.  There are two
+types of fees, {\bf wire fees} and {\bf coin fees}.  This chapter describes
+the fee structure.
+
+Fixed, amount-independent {\bf wire fees} are charged on wire transfers using
+the core banking system.  Details on wire fees are described in
+Section~\ref{sec:fees:wire}.
+
+Coin fees are more complex, as they do not exactly follow neither the usual
+percentage of volume model of other payment systems.  Instead, coin fees are
+applied per coin, resulting in a {\em logarithmic} fee structure.  As a
+result, the effective fee {\em percentage} for tiny transactions is high (for
+example 50\% for transactions of 0.0025 CHF) while the effective fee
+percentage for large transactions is nominal (for example $\approx$ 0.05\% for
+transactions of $\approx$ 40 CHF). Details on coin fees are described in
+Section~\ref{sec:fees:coin}.
+
+Fees are configurable (and that fee types beyond those described here are
+supported by the software). Thus, the specific fees may be adjusted in the
+future based on business decisions.  However, changes to the fees are never
+retroactively applied to coins already in circulation.  Wire fees that have
+been publicly announced for a particular time period also cannot be changed.
+Finally, any change to the terms of service must also be explicitly accepted
+by the users before they withdraw additional funds.
+
+
+\include{fees-wire}
+\include{fees-coins}
+%\include{fees-other}
+
+
+\end{document}
diff --git a/doc/flows/proc-aml.tex b/doc/flows/proc-aml.tex
new file mode 100644
index 000000000..04700faf8
--- /dev/null
+++ b/doc/flows/proc-aml.tex
@@ -0,0 +1,47 @@
+\section{AML process}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Action};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{staff}{\shortstack{AML staff \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Access \\ Token};
+      \end{tikzpicture}
+    }}
+    \postlevel
+    \mess[0]{wallet}{{Initial action}}{exchange}
+    \begin{callself}{exchange}{Establish AML requirement}{}
+    \end{callself}
+    \begin{callself}{exchange}{Queue AML task}{}
+    \end{callself}
+    \mess[0]{exchange}{Wait for AML}{wallet}
+    \mess[0]{staff}{Request AML work}{exchange}
+    \mess[0]{exchange}{{Open AML task(s)}}{staff}
+    \mess[0]{staff}{Request details}{exchange}
+    \mess[0]{exchange}{KYC/AML data}{staff}
+    \begin{callself}{staff}{Review and decide}{}
+    \end{callself}
+    \mess[0]{staff}{{Decision documentation}}{exchange}
+    \mess[0]{exchange}{AML decision}{wallet}
+    \mess[0]{wallet}{{Retry action}}{exchange}
+\end{sequencediagram}
+  \caption{Deposit interactions between customer, Taler exchange (payment
+    service provider) and the AML staff.  The process can be
+    triggered by various {\em actions} described in Chapter~\ref{chap:triggers}.
+    AML staff interactions are cryptographically secured and
+    decisions and the provided reasoning are archived by the exchange.
+    AML staff may interact with the customer (out-of-band)
+    in its decision process.
+    }
+  \label{fig:proc:aml}
+\end{figure}
diff --git a/doc/flows/proc-domestic.tex b/doc/flows/proc-domestic.tex
new file mode 100644
index 000000000..6ea43b8eb
--- /dev/null
+++ b/doc/flows/proc-domestic.tex
@@ -0,0 +1,66 @@
+\section{Domestic wallet check}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer wallet \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Wallet ID};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{sms}{\shortstack{Address validator}}
+
+    \postlevel
+    \mess[0]{wallet}{{P2P payment (Wallet ID)}}{exchange}
+    \begin{callself}{exchange}{New wallet?}{}
+    \end{callself}
+    \mess[0]{exchange}{Request address validation}{sms}
+    \mess[0]{sms}{Validation process ID}{exchange}
+    \mess[0]{exchange}{Request address validation}{wallet}
+    \mess[0]{wallet}{Send address}{sms}
+    \mess[0]{sms}{{Send PIN/TAN code (to address)}}{wallet}
+    \mess[0]{wallet}{Supply PIN/TAN code}{sms}
+    \mess[0]{sms}{{Confirmed customer address}}{exchange}
+    \mess[0]{exchange}{{Confirm completion}}{wallet}
+    \mess[0]{wallet}{{Retry action}}{exchange}
+\end{sequencediagram}
+  \caption{Deposit interactions between customer, Taler exchange (payment
+    service provider) and external address validation service.  The process can be
+    triggered by wallet-to-wallet (P2P) payments described in Chapter~\ref{chap:triggers}.}
+  \label{fig:proc:domestic}
+\end{figure}
+
+Our users have to accept the terms of service which restrict the use of the
+service to domestic customers.  For interactions with the core banking system,
+this simply means that we only accept payments from or to domestic bank
+accounts.  For P2P payments between wallets, we require that the wallets are
+controlled by a domestic entity.  We define domestic entities as those that
+are able to receive messages at a domestic address. Two types of addresses are
+supported:
+
+\begin{itemize}
+\item Control over a domestic {\bf mobile phone number} is established
+  by sending an SMS message with a PIN/TAN to the MSIN.
+\item Control over a domestic {\bf postal address} is established by
+  sending a letter with a PIN/TAN to the address.
+\end{itemize}
+
+Depending on the type of address, a validation has a limited validity period,
+as shown in Table~\ref{table:proc:domestic}.  When the validity period is
+over, a wallet has to re-do the address validation before they can receive any
+further funds through the service.
+
+\begin{table}[h!]
+  \caption{Restrictions on address validations}
+  \label{table:proc:domestic}
+  \begin{tabular}{l|l|r}
+    {\bf Type}          & {\bf Validity period} & {\bf Restricted to} \\ \hline \hline
+    Mobile phone number & 12 months             & {\em +41} \\
+    Postal address      & 36 months             & {\em Switzerland} \\
+  \end{tabular}
+\end{table}
diff --git a/doc/flows/proc-kyc.tex b/doc/flows/proc-kyc.tex
new file mode 100644
index 000000000..33883c40b
--- /dev/null
+++ b/doc/flows/proc-kyc.tex
@@ -0,0 +1,43 @@
+\section{KYC process}
+
+\begin{figure}[h!]
+  \begin{sequencediagram}
+    \newinst{wallet}{\shortstack{Customer \\
+      \\ \begin{tikzpicture}
+        \node [fill=gray!20,draw=black,thick,align=center] { Unique \\ Action};
+      \end{tikzpicture}
+    }}
+    \newinst[2]{exchange}{\shortstack{Taler (exchange) \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+    \newinst[2]{kyc}{\shortstack{KYC provider \\
+       \\ \begin{tikzpicture}[shape aspect=.5]
+        \tikzset{every node/.style={cylinder,shape border rotate=90, draw,fill=gray!25}}
+        \node at (1.5,0) {\shortstack{{{\tiny Database}}}};
+       \end{tikzpicture}
+    }}
+
+    \postlevel
+    \mess[0]{wallet}{{Initial action}}{exchange}
+    \begin{callself}{exchange}{Establish KYC requirement}{}
+    \end{callself}
+    \mess[0]{exchange}{Request new KYC process}{kyc}
+    \mess[0]{kyc}{{Process identifier (PI)}}{exchange}
+    \mess[0]{exchange}{{KYC required (PI)}}{wallet}
+    \mess[0]{wallet}{{KYC start (PI)}}{kyc}
+    \mess[0]{kyc}{{Request identity documentation}}{wallet}
+    \mess[0]{wallet}{{Upload identity documentation}}{kyc}
+    \begin{callself}{kyc}{Validate documentation}{}
+    \end{callself}
+    \mess[0]{kyc}{{Share documentation (PI)}}{exchange}
+    \mess[0]{kyc}{{Confirm completion}}{wallet}
+    \mess[0]{wallet}{{Retry action}}{exchange}
+\end{sequencediagram}
+  \caption{Deposit interactions between customer, Taler exchange (payment
+    service provider) and external KYC provider.  The process can be
+    triggered by various {\em actions} described in Chapter~\ref{chap:triggers}.}
+  \label{fig:proc:kyc}
+\end{figure}