Are you you?

I've been working on closing my American bank account. 6 weeks into the "project", I received a discomforting call: they couldn't process my request because my signature was unrecognizable. See, the more I sign my name, the less the name is legible. And, well, when I moved to the states for my postdoctoral fellowship, I had to sign a lot of papers. So today I ended up spending an hour trying to imitate my signature, circa 2010. Made me feel a bit... Weird. And because it was kind of silly, I faxed the new/old signature along with a copy of my passport and my bank card. If that isn't enough, I'm considering offering either my DNA or my right hand. Which would work better?