Adds solution to task 3

doc/report.tex

@@ -68,6 +68,21 @@ Concerning her home, Alice might have the following security goals which Mallory
 
 \section{Simple combinatorics}
 
+Let \( \mathbb{K} \) be the keyspace \textit{K} the key.
+
+
+\subsection*{a) ROT13}
+\texttt{ROT13} is the shift of an alphabet by 13 letters. Thereby it's a special case of the \textit{caesar} cipher (shift of an alphabet by \textit{k} letters). Thus 13 is the key and \( |\mathbb{K}| = 1 \).
+
+\subsection*{b) Vigenère Cipher}
+Let \textit{k} be the lenght of the chosen alphabet. Let \( |K| = n \). Thus \( \mathbb{K} = k^n \).
+
+\subsection*{c) 256 bit AES}
+\( \mathbb{K} = 2^{256} \).
+
+\subsection*{d) monoalphabetic substitution cipher}
+We assume that \textit{k} is the lenght of the alphabet. Thus \( \mathbb{K} = k! \).
+
 \section{XOR cipher}
 \begin{figure}[h]
     \centering