3 

     3 \usepackage{../langs}

   312 Again their solution made some good choices: 

   324 Again their solution made some good choices: for example

   313 

   325 voter authentication is done via the Estonian ID card,

   314 %\subsubsection*{Questions}

   326 which contains a chip like credit cards. They also made most

   315 

   327 of their source code public for independent scrutiny. Of

   316 %Coming back to the question of why I use online banking, but 

   328 this openness means that people (hacker) will look at your 

   317 %prefer not to e-vote. 

   329 fingers and find code such as

   330 

   331 {\footnotesize\lstinputlisting[language=Python,numbers=none]

   332 {../progs/estonia.py}}

   333 

   334 \noindent which can be downloaded from their github

   335 repository.\footnote{\url{https://github.com/vvk-ehk/evalimine/}}

   336 Also their system is designed such that Internet voting is

   337 used before the election: votes can be changed an unlimited

   338 amount of times, the last vote is tabulated, you can even

   339 change your vote on the polling day in person. This is an

   340 important security mechanism guarding against vote coercion,

   341 which of course is an important problem if you are allowed to

   342 vote via Internet.

   343 

   344 However, the weak spots in any Internet voting system are the

   345 voters' computers and the central server. Unfortunately, their

   346 system is designed such that they needs to trust the integrity

   347 of voters’ computers, central server components and also the

   348 election staff. In 2014, group of independent observers around

   349 Alex Halderman were able to scrutinise the election process in

   350 Estonia. They found many weaknesses, for example careless

   351 handling of software updates on the servers. They also

   352 simulated an election with the available software and were

   353 able to covertly manipulate results by inserting malware on

   354 the voters' computers. Overall, their recommendation is 

   355 to abandon Internet voting and to go back to an entirely

   356 paper-based voting process. In face of state-sponsered

   357 cyber-crime (for example NSA), Internet voting cannot be made

   358 secure with current technology. They have a small video

   359 clip with their findings at

   360 

   361 \begin{center}

   362 \url{https://estoniaevoting.org}

   363 \end{center}

   364 

   365 \noindent This brings us to the question, what could be a

   366 viable electronic voting process in

   367 \underline{\textbf{\emph{theory}}} with current technology?

   368 In the literature one can find proposals such as

   369 

   370 \begin{enumerate}

   371 \item Alice prepares and audits some ballots, then casts an

   372       encrypted ballot, which requires her to authenticate to

   373       a server.

   374 

   375 \item A bulletin board posts Alice's name and encrypted

   376       ballot. Anyone, including Alice, can check the bulletin

   377       board and find her encrypted vote posted. This is to

   378        make sure the vote was received by the server.

   379 

   380 \item When the election closes, all votes are shuffled and the

   381       system produces a non-interactive proof of a correct

   382       shuffling. Correct in the sense that one cannot determine

   383        anymore who has voted for what. This will require a 

   384        zero-knowledge-proof based shuffling procedure.

   385 

   386 \item After a reasonable complaint period to let auditors

   387       check the shuffling, all shuffled ballots are decrypted,

   388       and the system provides a decryption proof for each

   389       decrypted ballot. Again this will need a 

   390       zero-knowledge-proof-type of method.

   391 

   392 \item Perform a tally of the decrypted votes.

   393 

   394 \item An auditor can download the entire (shuffled) election

   395       data and verify the shuffle, decryptions and tally.

   396 \end{enumerate}

   397 

   398 \noindent As you can see the whole process is not trivial at

   399 all and leaves out a number of crucial details (such as how to

   400 best distribute public keys). It even depends on a highly

   401 sophisticated process called \emph{zero-knowledge-proofs}.

   402 They essentially allow one to convince somebody else to know

   403 a secret without revealing what the secret is. This is a kind

   404 of cryptographiv ``magic'', like the Hellman-Diffie protocol

   405 which can be used to establish a secret even if you can only

   406 exchange postcards with your communication partner. We will

   407 look at zero-knowledge-proofs in a later lecture in more

   408 detail. 

   409 

   410 The point of these theoretical/hot-air musings is to show that

   411 such an e-voting procedure is far from convenient: it takes

   412 much more time to allow, for example, for scrutinising whether

   413 the votes were cast correctly. Very likely it will also not

   414 pass the benchmark of being understandable to Joe Average.

   415 This was a standard a court rules that needs to be passed in

   416 the German election process. 

   417 

   418 The overall conclusion is that an e-voting process involving

   419 the Internet cannot be made secure with current technology.

   420 Voting has just too high demands on integrity and ballot

   421 secrecy. This is different from online banking where the whole

   422 process is designed around authentication. If fraud occurs,

   423 you try to identify who did what (somebody’s account got zero;

   424 somewhere the money went). Even if there might be even more 

   425 gigantic sums at stake in online banking than with voting,

   426 it can be solved. That does not mean there are no problems

   427 with online banking. But with enough thought, they can

   428 usually be overcome with technology we have currently. This

   429 is different with e-voting: even the best have not come

   430 up with something workable yet.

   431 

   432