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-Francois 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...