Add abstract and keywords.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

protocol/protocol.tex

@@ -7,9 +7,6 @@
 \RequirePackage{xspace}
 \RequirePackage{url}
 \RequirePackage{changepage}
-\RequirePackage[unicode,bookmarksnumbered,bookmarksopen,pdfview=Fit]{hyperref}
-\RequirePackage{cleveref}
-\RequirePackage{nameref}
 \RequirePackage{enumitem}
 \RequirePackage{tabularx}
 \RequirePackage{hhline}
@@ -17,6 +14,11 @@
 \RequirePackage{comment}
 \RequirePackage{needspace}
 \RequirePackage[nobottomtitles]{titlesec}
+\RequirePackage[hang]{footmisc}
+\RequirePackage{xstring}
+\RequirePackage[unicode,bookmarksnumbered,bookmarksopen,pdfview=Fit]{hyperref}
+\RequirePackage{cleveref}
+\RequirePackage{nameref}
 
 \RequirePackage[style=alphabetic,maxbibnames=99,dateabbrev=false,urldate=iso8601,backref=true,backrefstyle=none,backend=biber]{biblatex}
 \addbibresource{zcash.bib}
@@ -63,6 +65,10 @@
 \renewcommand{\arraystretch}{1.4}
 \overfullrule=2cm
 
+\setlength{\footnotemargin}{0.6em}
+\setlength{\footnotesep}{2ex}
+\addtolength{\skip\footins}{3ex}
+
 \renewcommand{\bottomtitlespace}{8ex}
 
 % Use rubber lengths between paragraphs to improve default pagination.
@@ -80,19 +86,31 @@
 
 \newcommand{\doctitle}{Zcash Protocol Specification}
 \newcommand{\leadauthor}{Daira Hopwood}
-\newcommand{\coauthors}{Sean Bowe | Taylor Hornby | Nathan Wilcox}
+\newcommand{\coauthora}{Sean Bowe}
+\newcommand{\coauthorb}{Taylor Hornby}
+\newcommand{\coauthorc}{Nathan Wilcox}
+
+\newcommand{\keywords}{anonymity, applications, cryptographic protocols,\
+electronic commerce and payment, financial privacy, proof of work, zero knowledge}
 
 \hypersetup{
   pdfborderstyle={/S/U/W 0.7},
   pdfinfo={
     Title={\doctitle, \docversion},
-    Author={\leadauthor\ | \coauthors}
+    Author={\leadauthor, \coauthora, \coauthorb, \coauthorc},
+    Keywords={\keywords}
   }
 }
 
+\makeatletter
+\renewcommand*{\@fnsymbol}[1]{\ensuremath{\ifcase#1\or \dagger\or \ddagger\or
+    \mathsection\or \mathparagraph\else\@ctrerr\fi}}
+\makeatother
+
 \renewcommand{\sectionautorefname}{\S\!}
 \renewcommand{\subsectionautorefname}{\S\!}
 \renewcommand{\subsubsectionautorefname}{\S\!}
+\renewcommand{\subparagraphautorefname}{\S\!}
 \newcommand{\crossref}[1]{\autoref{#1}\, \emph{`\nameref*{#1}\kern -0.05em'} on p.\,\pageref*{#1}}
 
 \newcommand{\nstrut}[1]{\texorpdfstring{#1\rule[-.2\baselineskip]{0pt}{\baselineskip}}{#1}}
@@ -699,21 +717,48 @@
 \newcommand{\pnote}[1]{\subparagraph{Note:}{#1}}
 \newenvironment{pnotes}{\introlist\subparagraph{Notes:}\begin{itemize}}{\end{itemize}}
 
+\newcommand{\affiliation}{\hairspace$^\dagger$\;}
 
 \begin{document}
 
 \title{\doctitle \\
-\Large \docversion \\
-\vspace{1ex} \large as intended for the \Zcash release of autumn 2016}
-\author{\Large \leadauthor \\ \Large \coauthors}
+\Large \docversion}
+\author{
+\Large \leadauthor\hairspace\thanks{\;Zerocoin Electric Coin Company} \\
+\Large \coauthora\affiliation | \coauthorb\affiliation | \coauthorc\affiliation}
 \date{\today}
 \maketitle
+
+\renewcommand{\abstractname}{}
 \vspace{-8ex}
+\begin{abstract}
+\normalsize \noindent \textbf{Abstract.}
+\Zcash is an implementation of the \term{Decentralized Anonymous Payment}
+scheme \Zerocash, with security fixes and adjustments
+to terminology, functionality and performance. It bridges the existing
+\emph{transparent} payment scheme used by \Bitcoin with a
+\emph{shielded} payment scheme secured by zero-knowledge succinct
+non-interactive arguments of knowledge (\zkSNARKs). It attempts to
+address the problem of mining centralization by use of the Equihash
+memory-hard proof-of-work algorithm.
+
+\vspace{0.5ex}
+This specification defines the \Zcash consensus protocol and explains
+its differences from \Zerocash and \Bitcoin.
+
+\vspace{2.5ex}
+\noindent \textbf{Keywords:}~ \StrSubstitute[0]{\keywords}{,}{, }.
+\end{abstract}
+
+\vspace{-10ex}
 \phantomsection
 \addcontentsline{toc}{section}{\Large\nstrut{Contents}}
 
 \renewcommand{\contentsname}{}
+% http://tex.stackexchange.com/a/182744/78411
+\renewcommand{\baselinestretch}{0.85}\normalsize
 \tableofcontents
+\renewcommand{\baselinestretch}{1.0}\normalsize
 \newpage
 
 
@@ -4006,6 +4051,13 @@ The errors in the proof of Ledger Indistinguishability mentioned in
 \introlist
 \nsection{Change history}
 
+\subparagraph{2017.0-beta-2}
+
+\begin{itemize}
+    \item Add abstract and keywords.
+\end{itemize}
+
+\introlist
 \subparagraph{2016.0-beta-1.13}
 
 \begin{itemize}