I had this great bicycle, once. I kept it in the walkway under my rowhouse in the Federal Hill neighborhood of Baltimore, locked behind a solid wooden gate. To protect it, I went out and bought a hefty padlock. The lock cost a fair amount, but my peace of mind was worth it. Then one morning, my neighbor knocked on my door and showed me a pack from the back of a bicycle, asking if it was mine. It sure looked familiar, but it couldn't be mine, because my bike was safely locked up. [..dream on..]
Eventually I found the padlock, above, discarded in the empty field across from my house. We never recovered the bicycle, of course. The lock itself wasn't attacked at all, as you can see. I have never bothered to open it. I found it exactly as it is pictured and I intend to keep it that way.
There is a lesson here for security architects who worry at length about the number of bits of key to use in a cipher or the security of a CA, but not about the computer, operating system, protocol, human interface or physical environment of the application allegedly made secure by that cipher or PKI.