There are significant security flaws in the ways that contracts are traditionally executed. This case illustrates just one of those flaws. Other flaws include a

There are significant security flaws in the ways that contracts are traditionally executed. This case illustrates just one of those flaws. Other flaws include alteration after signing, signature copying and forgery, and repudiation (meaning "I didn't sign that"). Most of these arise from the information security weaknesses inherent in paper documents and emailed PDFs. I have given a lot of thought to this problem. I even had a startup once devoted to solving it. My current thinking is that some form of digital signatures--perhaps PGP--is the best solution to all of this. As I discussed in a previous HN thread, we have a long way to go before the PGP user experience is acceptable for most computer-literate people. (When I say "user experience," I mean much more than the GUI. I mean the whole process of learning about PGP, creating keypairs, signing keys, etc..)