hws/hw02.tex
author Christian Urban <christian dot urban at kcl dot ac dot uk>
Mon, 21 Sep 2015 20:31:35 +0100
changeset 384 3a7c08f2bf5d
parent 372 486153025d71
child 389 9019f84ef99c
permissions -rw-r--r--
updated

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\begin{document}

\section*{Homework 2}

\HEADER

\begin{enumerate}
\item Often problems in e-voting are due to difficulties with
      authentication. Keep this in mind for what could go
      wrong with the following discount offered by an
      insurance company: John Hancock Insurance is partnering
      with Vitality, which you might know as one of those
      work-related wellness programmes. The programme is
      available in 30 US states. If you sign up for this, John
      Hancock will send you a free Fitbit monitor. That's a
      tiny, pill-shaped device that some people wear in
      sleek-looking bracelets to track how far they walk/run,
      the calories burned, and the quality of sleep. That
      means the insurance company would know exactly when a
      customer does a sit-up, how far she runs -- or when he
      or she has skipped the gym for a few days. For `good'
      customers there will be a discount in their premiums.
      Why is this a problem?


\item Voice voting is the method of casting a vote in the `open air' for everyone
present to hear. Which of the following security requirements do paper ballots 
satisfy \textbf{better} than voice voting? Check all that apply and give a brief explanation 
for your decision.

\begin{itemize}
\item[$\Box$] Integrity
\item[$\Box$] Enfranchisement
\item[$\Box$] Ballot secrecy
\item[$\Box$] Voter authentication
\item[$\Box$] Availability
\end{itemize}

\item Explain how an attacker can use chain voting in order to
  influence the outcome of a poll using paper ballots.

\item Which of the following mechanisms help with defending against
  chain voting? Check all that apply. Give a brief reason for each
  defence that mitigates chain voting attacks.

\begin{itemize}
\item[$\Box$] Using a glass ballot box to make it clear there are no
  ballots in the box before the start of the election.
\item[$\Box$] Distributing ballots publicly before the election.
\item[$\Box$] Checking that a voter's ID (drivers license, passport) matches the voter.
\item[$\Box$] Each ballot has a unique ID. When a voter is given a
  ballot, the ID is recorded. When the voter submits his or her
  ballot, this ID is checked against the record.
\end{itemize}

\item In the Estonian general election, votes can be cast via Internet
  some time before the election day. These votes cast via Internet can
  be changed an unlimited amount of times, the last vote is
  tabulated. You can even change your vote on the polling day in
  person. Which security requirement does this procedure address?

\item What is the main difference between online banking and e-voting? 
(Hint: Why is the latter so hard to get secure?)

\item Imagine, hypothetically, you have a perfectly secure Internet
  voting system, by which I mean nobody can tamper with or steal votes
  between your browser and the central server responsible for vote
  tallying. What can still go wrong with such a perfectly secure
  voting system, which is prevented in traditional elections with
  paper-based ballots?
\end{enumerate}


\end{document}

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