\documentclass[12pt]{article}
\usepackage[
    web={pro,forcolorpaper,usesf},
    eforms
]{aeb_pro}
% private package
%\usepackage[usecmtt]{myriadpro}

\DeclareDocInfo
{
    title={Approval Signing using AeB Pro},
    author=D. P. Story,
    university=Acro\negthinspace\TeX.Net,
    email=dpstory@acrotex.net,
    subject={How to sign a signature field},
    keywords={digital signatures, signing},
    talksite=\url{http://www.acrotex.net},
    talkdate={\today},
    copyrightStatus=True,
    copyrightNotice={Copyright (C) \the\year, D. P. Story},
    copyrightInfoURL=http://www.acrotex.net
}
\preparedLabel{AeB Blog}
\talkdateLabel{Published:}
\nocopyright

\DeclareInitView
{%
    windowoptions={showtitle}
}

\DeclarePageLayout
{%
    textwidth=\paperwidth-3in,
    oddsidemargin=.5in,
    evensidemargin=0pt,
    marginparwidth=0pt,
    marginparsep=0pt,
}

\newcommand{\cs}[1]{\texttt{\char`\\#1}}

\pagestyle{empty}
\parskip\medskipamount
\parindent0pt

\begin{docassembly}
\sigInfo{% creates the oSigInfo object
    cSigFieldName: "sigOfDPS",
    cert: "D_P_Story.pfx", password: "mypassword",
    oInfo: { location: "Niceville, FL",
      reason: "I am approving this document",
      contactInfo: "dpstory@acrotex.net",
      appearance: "My Signature" }
};
\signatureSign
\end{docassembly}

\begin{document}


\maketitle

\hfill\smash{\raisebox{-\baselineskip}{March 23, 2009}}

\begin{tabular}{@{}ll}
To:         &Honorable Barrister Maxwell Frimpong\\
From:       &D. P. Story\\
Subject:    &On Business Proposal\\
\end{tabular}

\vspace{2\baselineskip}

Dear Mr.\ Frimpong;

Thank you for thinking of me concerning an ``important business
proposal'' in your recent and brief email to me on March 23, 2009.
Recovering \$12,000,000 (twelve million  Us dollars) in claims
sounds intriging and exciting to me. Such a large amount of money
would certainly come in handy in these tough times. Yet,
regrettably, I must decline you kind offer; though I am in
retirement, I am, none-the-less, quite busy lately sorting my button
collection, and don't really have the time to pick up all this easy
money.

Thank you again, Barrister Frimpong, for your offer. Please keep me
in mind should future opportunities arise.


\vspace{2\baselineskip}

Best regards,\\
\sigField{sigOfDPS}{2.5in}{4\baselineskip}\\[3pt]
Dr.\ D. P. Story\\
Department of Mathematics,\\
Talking University\\
Talkville, FL 12345\\
\texttt{dpstory@uakron.edu}


\newpage

\section{Creating and Signing a Signature Field}

The \textsf{eforms} package can create a signature field with the \cs{sigField} command, and
using the \textsf{aeb\_pro} package with its \texttt{docassembly} environment, can also sign the field
from a {\LaTeX} source.

The {\LaTeX} code for creating the signature field of this document is
\begin{verbatim}
Best regards,\\
\sigField{sigOfDPS}{2.5in}{4\baselineskip}\\[3pt]
Dr.\ D. P. Story\\
Department of Mathematics,\\
Talking University\\
Talkville, FL 12345\\
\texttt{dpstory@uakron.edu}
\end{verbatim}
The \cs{sigField} command appears in the second line, and uses the usual syntax
for form fields, as defined in the \textsf{eforms} package. The optional parameter,
shown used in this example, is used to change the appearance of the (unsigned) field,
and to associate JavaScript actions. Here's what the field looks like when it is unsigned.

\sigField{sigOfDPS1}{2.5in}{4\baselineskip}

Once the field is created, it can be signed using the Acrobat user
interface, or programmatically, from the {\LaTeX} source file. The
code for the first signature field of this document is

\begin{small}
\begin{verbatim}
\begin{docassembly}
\sigInfo{% creates the oSigInfo object
    cSigFieldName: "sigOfDPS",
    cert: "D_P_Story.pfx", password: "mypassword",
    oInfo: { location: "Niceville, FL",
      reason: "I am approving this document",
      contactInfo: "dpstory@acrotex.net",
      appearance: "My Signature" }
};
\signatureSign
\end{docassembly}
\end{verbatim}
\end{small}%
where I have changed the value of the \texttt{password} key to
protect my secrets. The first command, \cs{sigInfo}, creates an
JavaScript object, \texttt{oSigInfo}. The command \cs{signatureSign}
uses the information in this object to sign the field designated by
the \texttt{cSigFieldName} property.

Additional information on signatures can be found
at the \href{http://www.adobe.com/go/acrobat_developer}{Acrobat Developer Center};
or go to the \href{http://www.adobe.com/go/acrobat_security}{Acrobat Security} page;
look for the document titled \textsl{Digital Signature User Guide for Acrobat 9.0
and Adobe Reader 9.0}.

The \emph{JavaScript for Acrobat API Reference}\footnote{Available through the
\href{http://www.adobe.com/go/acrobat_developer}{Acrobat Developer Center}.} for details
on these methods and their parameters.

Now, back to my retirement.

\end{document}