Author: AMH

I hadn’t run into the unsolved Dorabella cipher before (that I remember). If you enjoy such things I highly recommend this account of it, with its many proposed decryptions that make clear why one of the conditions for a verified solution is that it “be self-evident”. It’s an excellent example of why decyphering without context is hard (maybe impossible?). And I enjoy the proposed solution that takes encryptions errors into account as a possibility, considering that it was done by hand, and by someone considered prone to such errors.

Nothing like avoiding end-of-the-year physical cleanup with end-of-the-year virtual cleanup! I finally got around to reading this detailed description of how Bitcoin works, recommended by Schneier on his weblog, and I need to hang on to this for next time I’m teaching security. From a teaching perspective, it does a nice job of showing how all of the various types of cryptography come together in an interesting way in this protocol. This is the part that always seems sort of wild to me: The idea is to make it so everyone (collectively) is the bank. In particular, we’ll assume that … Continue reading How It Works: Bitcoin Edition

First, and most important obviously, this is pretty neat research into training robot motion with online, and non-optimal, feedback. It’s a nice consideration of the type of feedback one is likely to get, or to get easily. And the illustrative video on their page is pretty great (I found the moment when they showed the robot how to point the knife towards itself, not someone else, adorable…) But it’s also worth noting that the TechCrunch story on the research is pretty hysterical: “Cornell Researchers Help Robot Unlearn Stabby Motions With A Human Trainer”.

There’s something unavoidable about Wikipedia, even when you acknowledge its flaws, which makes it a constantly interested phenomenon to investigate and analyze. As the article notes, its rankings in search results and use in question answering systems like Siri only make it more interesting to understand what’s going on with it. Looking at the effect of the editorial structure and automated tools for handling edits is particularly interesting; I hadn’t really thought about the effect of bots on participation in this way: In their paper on those findings, the researchers suggest updating Wikipedia’s motto, “The encyclopedia that anyone can edit.” … Continue reading Building the right community for community editing

This is awesome – I’ve long been in love with intrusions that rely on listening in on the sound of keystrokes, or the wiggle of a laptop screen, or what have you to learn and then reproduce what has been typed. This variation where a smartphone on your desk can pick up typing vibrations and from there learn to recognize what you are typing. It’s proof of concept, not found out in the wild at this point, but still very cool.

Starting out as an explanation of the traveling salesman problem, this article goes on to also be an excellent, and I think understandable, explanation of what an algorithm is and computational complexity. If you want to get a quick sense of what computer science is concerned about that goes beyond just “how to program”, and is more the “how to solve problems” side of things, this is a good read. In 2006, for example, an optimal tour was produced by a team led by Cook for a 85,900-city tour. It did not, of course, given the computing constraints mentioned above, … Continue reading Traveling Happy Truck Drivers