Introduction - Burdens of Proof - page 13

ticular, the inherently difficult problem of key distribution; the design
trade-offs that seem to perpetually obtain between high-grade security and
user-friendliness; and, given the special interest of the state in both listen-
ing to and securing important communications, the unique structural
forces that have shaped the development of the field.
In chapter 3, “On the Brink of a Revolution,” I analyze a turning point
in the history of cryptographic innovation, the 1976 publication of Diffie
and Hellman's “New Directions in Cryptography.” The founding docu-
ment of cryptography's modern era, “New Directions” argued not only for
radically new applications of cryptography for the coming age of computer
networks, but also for a new paradigm of provable security based on the
certification of cryptosystems through the mathematical frameworks of
complexity theory and algorithmics. The invention of public-key cryptog-
raphy unleashed a creative explosion in the field, the growth of a research
community independent of the military and intelligence establishment,
and the development of a broad research program aiming at providing all
functions necessary to the integrity of electronic information, including
the signatures needed to secure e-commerce transactions. In addition to
these achievements, by the 1990s cryptography had also emerged as the
Internet's first native political movement and cyberlibertarianism's most
prominent voice. However, this chapter underlines how cryptography's
emerging scientific program supported a broad range of positions on the
social purposes of cryptographic research, many of a more conservative
bent than crypto's well-publicized image suggested.
In chapter 4, “The Equivalent of a Written Signature,” I examine the
gradual crystallization of a cryptographic model for an “electronic equiva-
lent to handwritten signatures.” The model defines both the function of
signatures, that is, the provision of the three security services of identifica-
tion, integrity, and non-repudiation, as well as the specific threats and
adversaries these services must protect against. The market demise of
public-key infrastructures provides a concrete and powerful critique of the
digital signature model, in addition to a powerful reminder that key
distribution remains the Achilles' heel of any large-scale deployment of
cryptographic technologies. I argue the considerable difficulties met in
translating this model into a commercially successful technology point to
cryptographers' problematic relationship with the representational nature
of models. In adopting the ideals, methodologies, and epistemological