Burdens of Proof

Burdens of Proof

Cryptographic Culture and Evidence Law in the Age of Electronic Documents

By Jean-François Blanchette

An examination of the challenges of establishing the authenticity of electronic documents—in particular the design of a cryptographic equivalent to handwritten signatures.





An examination of the challenges of establishing the authenticity of electronic documents—in particular the design of a cryptographic equivalent to handwritten signatures.

The gradual disappearance of paper and its familiar evidential qualities affects almost every dimension of contemporary life. From health records to ballots, almost all documents are now digitized at some point of their life cycle, easily copied, altered, and distributed. In Burdens of Proof, Jean-François Blanchette examines the challenge of defining a new evidentiary framework for electronic documents, focusing on the design of a digital equivalent to handwritten signatures.

From the blackboards of mathematicians to the halls of legislative assemblies, Blanchette traces the path of such an equivalent: digital signatures based on the mathematics of public-key cryptography. In the mid-1990s, cryptographic signatures formed the centerpiece of a worldwide wave of legal reform and of an ambitious cryptographic research agenda that sought to build privacy, anonymity, and accountability into the very infrastructure of the Internet. Yet markets for cryptographic products collapsed in the aftermath of the dot-com boom and bust along with cryptography's social projects.

Blanchette describes the trials of French bureaucracies as they wrestled with the application of electronic signatures to real estate contracts, birth certificates, and land titles, and tracks the convoluted paths through which electronic documents acquire moral authority. These paths suggest that the material world need not merely succumb to the virtual but, rather, can usefully inspire it. Indeed, Blanchette argues, in renewing their engagement with the material world, cryptographers might also find the key to broader acceptance of their design goals.


$34.00 X ISBN: 9780262017510 288 pp. | 6 in x 9 in 28 b&w illus., 3 tables


  • Throughout his discussion, Blanchette offers keen insight into the interplay between cultural presumptions and biases inherent in both cryptographic and legal cultures.

    Law Library Journal


  • Jean-François Blanchette has written more than the history of electronic signatures; this is a masterful account of how—as we enter the digital age—our ideas of authenticity remain solidly anchored in our analog past. What emerges is a gripping tale, untold so far, of high aspirations, dashed hopes, and an epic struggle. Uncovering why and how digital technologies fail to change professions and society, Burdens of Proof is a truly important book.

    Viktor Mayer-Schönberger

    Oxford Internet Institute

  • This book is a wonderful weave of social and technical analysis of the history of cryptography, unified by a passion for exploring the material nature of computers. With grace and wit, Blanchette has produced a work which makes a major contribution to our understanding of complex configurations of the virtual and the real.

    Geoffrey C. Bowker

    Department of Informatics, University of California, Irvine

  • A technology guaranteeing the authority of electronic documents would appear an essential tool of the digital age, which is why there is so much to learn from the failure to develop one. Jean-François Blanchette shows that understanding this failure requires addressing the historical evolution of contemporary cryptography and the legal concerns such a technology raises, together with a fearsome array of contextual issues ranging from state power to the materiality of mathematics. In contrast with the parochialism of much contemporary academia, Blanchette explains these events through an exemplary embrace of the requisite skills of a polymath.

    Daniel Miller

    Professor of Material Culture, University College London