Week 4: Scripting Difficulties

I went down to Tennessee to attend my cousin’s high school graduation commencement and spend my Memorial Day vacation with the family. When I came back to the lab on Wednesday, I started out by trying to dig deeper into the paper on boot-time entropy in embedded devices. I tried to decipher the confusing diagrams used in the Results and Analysis section, ranging from histograms to per-test distributions to graphs of entropy over correlation threshold. While I still do not fully understand some of the statistical analysis that was done, I believe I have a better understanding of the underlying conclusion. Even with the techniques proposed to gather boot-time entropy, embedded devices are still at a disadvantage because they lack randomness from radios that wireless devices can utilize and previously saved entropy that desktops can use. These headless devices need to gather strong entropy immediately following the boot, before a network connection even occurs.

Next, I watched Dr. Avi Wigderson’s talk on Randomness and Pseudorandomness, which had been sent to me by Amir. The talk introduced several interesting real-life applications of the importance of randomness such as the P vs. NP problem, which aims to find a deterministic problem that is exponentially hard to solve – something which is trivial for non-deterministic problems. Perhaps the most intriguing part of Dr. Wigderson’s lecture, however, was his observation that randomness is relative to the computing power of the observer. He uses the example of a coin toss. An observer equipped with only his or her own eyesight will probably not be able to correctly determine the outcome of the toss with greater than 50% success rate. On the other hand, if the observer is equipped with several high-speed cameras, state-of-the-art sensors, and sophisticated momentum-measuring software, he or she will be able to predict the outcome with 100% success.

Finally, I have been facing many obstacles in writing a script to automatically download random bytes from randomserver.dyndns.org. I am used to programming on Linux, so it has taken me some time to get used to my programming environment on Windows 8. I installed Python 3.3 and twill, a Python extension that automates HTML form filling and submission. I was not able to successfully install twill, and I spent a considerable time trying to figure out what was going wrong. Eventually, I found out that the open-source code for twill was written for Python 2.5 in which ‘print’ is not a function and therefore does not wrap the argument in parentheses. I briefly attempted to write a script that would fix the print statements in all the Python scripts that were part of the twill code. I quickly realized, however, that not all the print statements outputted to the terminal, which would make fixing the scripts much more difficult. Also, there might be other differences between versions 2.5 and 3.3 that might make the installation fail anyway. My next step will be to install Python 2.5 so I can successfully install twill and get the random byte download script to work.