Articles tagged: uncategorized

Martin Kleppmann: Accounting for Computer Scientists

I just found a great blog post by Martin Kleppmann titled Accounting for Computer Scientists, a succinct introduction to double-entry accounting (although he doesn’t refer to it as such) in terms of basic graph theory:

Eventually I figured it out: basic accounting is just graph theory. The traditional ways of representing financial information hide that structure astonishingly well, but once I had figured out that it was just a graph, it suddenly all made sense.

He goes on to illustrate how a profit-and-loss statement and a balance sheet can be visualized on a simple DAG.  Good stuff…

Ars Technica “Getting to QED

Ars Technica has a four-part introductory series on logic and argumentation, entitled “Getting to QED.”

In some cases, there is a way to tell good arguments from bad using what is called informal logic. This name distinguishes it from formal logic, which is used in mathematics; natural language is less precise than mathematics, and does not always follow the same rules. Perhaps more surprisingly, the name also reflects the fact that there is a lot of disagreement over what it means. Informal logic is actually a fairly young discipline, developed in the 1960s, and intended to apply new techniques from formal logic to argument and critical thinking. Philosophers are still wrestling with this application, and there are several competing schools of thought.

For all the differences, there are some core elements upon which everyone agrees. This article is a tutorial introducing these basic ideas of informal logic. In particular, we focus on deductive reasoning, which is one of the cornerstones of analytical thought. Hopefully you will come away from this article with the tools to distinguish a productive debate from an acrimonious flame war.

This should be required reading for anyone who’s engaged in debate on a mailing list or web forum.

MacGyver movie!

I’ve been waiting for this since I was a kid: MacGyver is headed for the theater! And better yet, the show’s original creator, Lee David Zlotoff, has obtained the movie rights and will be in control of the film. This is going to be amazing.

I have to assume right off the bat that Richard Dean Anderson will be reprising the role of Angus MacGyver… just don’t skimp on the mullet, ok guys?


The University’s software licensing program proudly furnishes UF engineering students with Microsoft’s latest-and-greatest (with the notable exception of cash cow Microsoft Office). As of Wednesday, latest-and-greatest meant Windows Vista Business Edition*, so I decided to download it and, with the help of Boot Camp, give it a run on my iMac. Here are my notes and impressions, in no particular order:

  • It’s faster than I expected. It takes almost twice as long as OS X to boot, but programs (subjectively) seem to start more quickly.
  • The new user interface is nice. I still prefer Exposé to Flip3D, but things such as real-time previews of taskbar items and a hardware-accelerated UI make this the first version of Windows that I actually feel comfortable while using.
  • User Account Control is a mess. Some operations, such as touching a file in C:\Program Files\, require you to confirm your intent twice – once for UAC, and once again for what appears to be some manifestation of Windows Security Center. Talk about the left hand not knowing what the right is doing.
  • AutoPlay finally asks for your confirmation before automatically executing whatever program or virus might be on that CD you just stuck in your computer. A small touch, but this one’s been a long time coming.
  • Data Execution Prevention (NX bit support) is enabled by default for the operating system, and optionally for the rest of your programs as well. This didn’t seem to cause any problems with the relatively small set of software that I’ve installed so far. Apple needs to bring this feature to OS X as soon as possible.
  • The whole system seems quite a bit less naggy than XP was about activating your OS and so on. Granted, “less naggy than XP” might not be saying much, but it goes a long way to improve the overall user experience.
  • It isn’t entirely stable. The whole system locked up on me three times while I attempted to install (the admittedly not-entirely-Vista-ready, but-whose-fault-is-that) Microsoft Visual Studio 2005. That shouldn’t happen.

Aside from DRM issues, Vista really is a solid improvement over XP. In particular (and I’ll probably get burned at the stake for saying this), Vista is interesting because it may represent the first time in PC history that Microsoft Windows is, on paper but probably not in practice, on par with or better than the most prominent “alternative” desktop operating systems in terms of security against remote attack. I would really like to see OS X pick up heap-side support for the NX bit to complement the protection already in place against stack overrun attacks, and both OS X and the most popular Linux distributions integrate an analogue to Vista’s OpenBSD-inspired address space layout randomization.

However, despite the extended Beta stage Windows Vista still doesn’t have the feel of a finished product. Things like the quirkiness of UAC and possible stability issues (not to mention the lack of an entirely Vista-ready version of Visual Studio) make me recommend that anyone who relies on Windows as a primary operating system hold back from upgrading just yet, at least until the first service pack rolls around the corner. As history shows, one can never be too cautious with a first-iteration Microsoft product.

*Too bad they couldn’t spring for Microsoft Windows Vista Ultimate Upgrade Limited Numbered Signature Edition. Yes, it’s real.

Bill Amend is my hero

Thank you, Mr. Amend, for giving the dangers of electronic voting machines some much-needed press. The more people who are informed about such a frightening threat to our democratic process, the better.

In an attempt to convince a complacently skeptical public of just how much a problem that direct-recording electronic voting machines pose, Jon Stokes of Ars Technica has written a guide, How to steal an election by hacking the vote, which illustrates just how easy it is to hijack an election conducted entirely over electronic media.

If nothing else, watch this video by the security researchers at Princeton University’s Center for IT Policy, wherein researchers demonstrate how to load a malicious payload onto a Diebold voting machine in under one minute. Come election day, this payload, a computer virus which spreads to other machines through normal memory card exchange, silently skews the vote toward its preferred candidate; these alterations are made untraceable by the fact that these voting machines provide users with no voter-verifiable paper trail. Such a virus could even delete itself once the election has concluded, leaving behind no evidence within the machine itself.

In concluding his article, Mr. Stokes sums up the problem nicely:

  • Bits and bytes are made to be manipulated; by turning votes into bits and bytes, we’ve made them orders of magnitude easier to manipulate during and after an election.
  • By rushing to merge our nation’s election infrastructure with our computing infrastructure, we have prematurely brought the fairly old and well-understood field of election security under the rubric of the new, rapidly evolving field of information security.
  • In order to have confidence in the results of a paperless DRE-based election, you must first have confidence in the personnel and security practices at these institutions: the board of elections, the DRE vendor, and third-party software vendor whose product is used on the DRE.
  • In the absence of the ability to conduct a meaningful audit, there is no discernable difference between DRE malfunction and deliberate tampering (either for the purpose of disenfranchisement or altering the vote record).

Although researchers have been warning us of the dangers of direct electronic voting for a long time, by now it is too late to change this state of affairs before next month’s elections. However, afterwards - if you are as troubled as I am about these challenges to the transparency and verifiability of our democratic process - contact your congresscritters and tell them to support voter-verified paper record legislation.