Cryptography Reference
In-Depth Information
used to audit the trustees, which have to reveal half of the connections to the
following batch by publishing the removed layer of the doll, which again allows
anyone to verify these connections. But the choice was made in a way such
that there will be no complete path visible leading from a scanned slide to
its ballot image. In [7], a refinement of the choice is described, which ensures
that nothing can be learned about the ballots of even groups of voters.
But how can the voter be sure that she was not cheated by the voting
machine printing a false second (and later destroyed) slide letting her see her
ballot image but producing a different one after passing all the mixes? The
idea is that after the voting machine printed the visual cryptography part on
the laminated slides, the voter has still the choice to take the upper or lower
slide as receipt and tell the choice to the voting machine before it continues
by printing the barcode of the doll to it; in this way the voting machine would
for each voter only have a 50% chance of cheating without being caught.
12.8 Conclusion
Visual cryptography is a fascinating technique and very intuitive to the user.
However, it is surprising that within the last 15 years since its invention by
Naor and Shamir only a few suggestions have been made to apply it to prac-
tical problems. In this paper we presented Naor and Pinkas technique to use
visual cryptography in order to protect online transactions against manipula-
tion and Chaum's idea to apply it to verify the correctness of the outcome of
an election. Because of diculties like adjustment, multiple use, and costs of
special equipment, these suggestions did not lead to applications that are used
for serious purposes. But in the future, further developments of the ideas pre-
sented in this paper, as well as new ideas, could spread practical applications
of visual cryptography.
Bibliography
[1] Sebastian Beschke.
Implementierung der Cardano-TAN (cTAN), 2009.
Studienarbeit.
[2] B. Borchert. Segment-based visual cryptography. Technical Report WSI{
2007{04, Universitat Tubingen (Germany), Wilhelm-Schickard-Institut
fur Informatik, 2007.
[3] B. Borchert and K. Reinhardt. Abhor- und manipulationssichere Ver-
schlusselung fur Online Accounts mittels Visueller Krytographie an der
Search WWH ::
Custom Search