DIGITAL SIGNATURES AND ELECTRONIC DOCUMENTS:

Abstract Often, the main motivation for using PKI in business environments is to streamline workflow, by enabling humans to digitally sign electronic documents, instead of manually signing paper ones. However, this application fails if adversaries can construct electronic documents whose viewed contents can change in useful ways, without invalidating the digital signature. In this paper, we examine the space of such attacks, and describe how many popular electronic document formats and PKI packages permit them

This thesis incorporates material from the paper “Digital Signatures and Electronic Documents: A

The natural progression today is to use electronic documentation instead of paper in order to streamline the business environment. For digitally signed electronic documentation to be incorporated in today’s market, people need to have at least as much faith in them as paper. My thesis explores the flaws in how many popular electronic document formats and COTS PKI packages mesh together, and how adversaries can construct digital documents whose viewed contents can change in useful ways without invalidating the signature using these flaws, and will also discuss some countermeasures. ii Acknowledgments There are many people to thank and I would like to start with my girlfriend Elizabeth who has supported me throughout this process and helped me through this writing, my parents who have supported me throughout my life and encouraged all my choices. Another important person I must thank is my advisor, Professor Sean Smith who has provided guidance, assistance and continuous support over the last two years. He has always been there to point the way, provide insight, and take part on all aspects of this thesis work. His intellectual originality, astute suggestions and fresh approach have been invaluable for this thesis research. I could never thank him enough for being an exceptional adviser