Cryptography Reference
In-Depth Information
rion of “unplugged cryptography” into the single design objective of
simplicity
: cryptographic protocols should exhibit both ease of implemen-
tation and understanding, and parties to them “should be required to
expend only a small amount of time, energy, and money to learn, use, and
be confident in the protocol.”
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The paper was motivated by a real-life
situation: during a conversation, two managers at a company realize they
both have received confidential complaints about the same sensitive
matter. In confiding to each other, they face a dilemma: if the complaints
originate from two different individuals, their privacy will have been
compromised.
Cryptographers have developed sophisticated protocols for this problem
of “secret function evaluation.”
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Such protocols would allow the managers
to carry this type of conversation over electronic networks, without relying
on any trusted third parties, with mathematical guarantees that their con-
versation will not leak any information whatsoever. Such guarantees come
at a cost however: the protocols “are complex schemes that only certain
experts can be expected to understand. Thus, blind trust is given to the
system designer. An additional point is that these solutions are not yet
genuinely practical, even if implemented with the best possible care. Our
goal in this article is to provide some schemes whose implementation is
so transparent that no expertise is needed to verify correctness. We hope
that some of these schemes will provide not only practical solutions to
our problem, but also insight into the subtleties of communication and
information.”
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Fagin, Naor, and Winkler eventually come up with fourteen different
solutions for the managers' problem, with different trade-offs between
design criteria.
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The last solution is provided by the first author's thirteen-
year-old son, who wonders why the managers can't simply inquire directly
to the complaining parties. Indeed, in the end, this will be the solution
that the managers adopt to resolve their conundrum.
Conclusion
The controversies and research projects outlined in this chapter point to
an intriguing dynamic. Although modern cryptography sought to ground
its practices in abstract mathematical worlds of binary information, number
theory, and computational complexity, several material phenomena made
