diff --git a/chapter-qkd/chapter.pdf b/chapter-qkd/chapter.pdf
index ad0b137..83c6ee1 100644
Binary files a/chapter-qkd/chapter.pdf and b/chapter-qkd/chapter.pdf differ
diff --git a/chapter-qkd/chapter.tex b/chapter-qkd/chapter.tex
index c44e45f..c2e22a6 100644
--- a/chapter-qkd/chapter.tex
+++ b/chapter-qkd/chapter.tex
@@ -67,10 +67,14 @@
     }
 }
 
+\renewcommand{\thesection}{\arabic{section}}
+\renewcommand{\thesubsection}{\arabic{section}.\arabic{subsection}}
+\renewcommand{\thesubsubsection}{\arabic{section}.\arabic{subsection}.\arabic{subsubsection}}
+
 % Re-define heading formats to force single line spacing
 \titleformat{\section}{\normalfont\large\bfseries\singlespacing}{\thesection}{1em}{}
-\titleformat{\subsection}{\normalfont\large\bfseries\singlespacing}{\thesection}{1em}{}
-\titleformat{\subsubsection}{\normalfont\large\bfseries\singlespacing}{\thesection}{1em}{}
+\titleformat{\subsection}{\normalfont\large\bfseries\singlespacing}{\thesubsection}{1em}{}
+\titleformat{\subsubsection}{\normalfont\large\bfseries\singlespacing}{\thesubsubsection}{1em}{}
 
 \newcommand{\degree}{\ensuremath{^\circ}}
 \newcolumntype{P}[1]{>{\centering\arraybackslash}p{#1}}
@@ -93,7 +97,7 @@
 
 \raggedbottom
 
-\renewcommand{\chaptermark}[1]{\markboth{#1}{}}
+\renewcommand{\chaptermark}[1]{\markboth{Chapter \thechapter: #1}{}}
 \renewcommand{\sectionmark}[1]{\markright{\thesection\ #1}}
 \addtolength{\headwidth}{\marginparsep}
 \addtolength{\headwidth}{\marginparwidth}
@@ -104,7 +108,7 @@
         \setlength{\fboxsep}{2mm}
         \shadowbox{
             \parbox{3cm}{
-                \setstretch{1.0}
+                \singlespacing
                 \raggedright
                 \textsf{
                     \small\textbf{To do}\\