Cryptography Reference
In-Depth Information
conditions necessary for the long-term legibility of electronic documents
present a significant challenge to the forensic value of cryptographic sig-
nature verification.
Chapter 7, “The Cryptographic Imagination,” returns to a defining
feature of modern cryptography: its ability to provide mathematical certi-
fication of the effectiveness of cryptosystems, in contrast to the heuristic
methods of yore.
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The last decade has seen two important challenges to
this element of Diffie and Hellman's project: first, a new powerful class of
“side-channel attacks” that has required cryptographers to take into
account the physical embodiment of mathematical algorithms in comput-
ing devices; second, a long-standing controversy over the scope of the
mathematical idealizations under which “provable security” obtains. I
argue that both issues point to the representational nature of models as
the source of inescapable gaps between the mathematics of cryptography
and their concrete realization in software and hardware artifacts. I then
provide examples of successful integration in cryptographic models of the
embodied capabilities of human beings—including memory, perception,
and cognition—and of the security properties of familiar material technol-
ogies—including books, paper, and envelopes. Such integration, I suggest,
may provide a potential avenue toward broader social acceptance of cryp-
tographic design goals.
In the epilogue, I revisit the preceding arguments in light of another
major area of cryptographic investigation: voting technologies. Because
their design proceeds from assumptions similar to those that informed the
cryptographic signature model, I suggest their widespread adoption will
likely face similar difficulties. I argue that directly addressing these blind
spots will enable cryptographers to more fully account for the
creative
dimension of their design practices and help reinvigorate their sociotechni-
cal agenda.
