Electronic signature legislation seeks to facilitate e-commerce by providing an electronic equivalent to handwritten signatures in paper-based contracts. However, electronic signature legislation enacted in the past years in different jurisdictions has followed a dissimilar approach. In light thereof, this book analyzes the legal validity of electronic signatures in international contracts potentially subject to divergent electronic signature regulation. To this end, four major issues are addressed: the technological and legal concept of electronic signatures; the legal regulation of electronic signatures; the determination of the electronic signature legislation that will be applicable to an international contract; and, finally, the implications of applying one electronic signature law or another. The research covers the laws of Argentina, Germany and the United States of America as well as international conventions.