Matt Blaze's
Science, Security, Curiosity
Archives: January 2007

We often say that researchers break poor security systems and that feats of cryptanalysis involve cracking codes. As natural and dramatic as this shorthand may be, it propagates a subtle and insidious fallacy that confuses discovery with causation. Unsound security systems are "broken" from the start, whether we happen to know about it yet or not. But we talk (and write) as if the people who investigate and warn us of flaws are responsible for having put them there in the first place.

Words matter, and I think this sloppy language has had a small, but very real, corrosive effect on progress in the field. It implicitly taints even the most mainstream security research with a vaguely disreputable, suspect tinge. How to best disclose newly found vulnerabilities raises enough difficult questions by itself; let's try to avoid phrasing that inadvertently blames the messenger before we even learn the message.

I've long been an admirer of the James Randi Educational Foundation (JREF), tireless advocates for critical thinking, skepticism, and the scientific method. They offer a one million dollar prize to the first person who can provide convincing, testable proof of supernatural powers. The foundation recently set up a "remote viewing" challenge in which the purported psychic is asked to describe the contents of a special sealed box held at the JREF office in Fort Lauderdale, Florida.

Those who know me may be surprised to read this, but I'm pleased to announce that Jutta Degener and I have successfully visualized the contents of Randi's challenge box. We accomplished this from over a thousand miles away and entirely through mental concentration and the application of our unique talents (or, I should say, gifts), and without any physical access or inside information. We can now reveal to the world the item in the box: a small mirrored flat circular wheel or disk, such as a DVD or CD. Randi, if you're reading this, a money order or certified check will be fine.

This Spring at Penn, Jonathan Smith and I are co-teaching CSE125: Technology and Policy, a new seminar-format interdisciplinary course on, well, technology and policy. Whether you're a techno-geek, a policy wonk, or just hope to understand why the music industry is behaving so strangely, check out the (still very preliminary) course web page and syllabus here and consider attending. We meet in Towne 321, Tuesdays and Thursdays, 1200-1330 (that's noon to 1:30pm, for you non-nerds).

I saw an interesting story (thanks to Dave Farber's Interesting-People list) on how the TSA is considering selling advertising space at airport security checkpoints. My distaste at the prospect of being subjected to ads during these already humiliating and irritating screenings aside, I found the most fascinating part of this article to be its glimpse at the officious technical jargon that has emerged for airport security paraphernalia. Those grey tubs that you put your laptop in (after removing it from its case, of course) are apparently properly called "divestiture bins"; after X-ray, we retrieve our items at the "composure tables". I don't know about you, but I don't usually feel especially composed after making it through a long security line.

I'd say you can't make this stuff up, but apparently someone does.

Newly armed with the official terminology, I did a bit of googling this morning and found the TSA's Airport Security Design guidelines. This 333 page (PDF format) manual specifies, in all the detail one could ever hope for, everything there is to know about designing the security infrastructure for an airport, right down to the layout of the divest tables for the X-ray ingress points at sterile concourse station SSCPs. It's all very meticulous and complete, even warning of the "potential for added delay while the passenger divests or composes" (page 99). For some geeky reason, I find all this mind-numbing detail about the physical architecture of security to make strangely compelling reading, and I can't help but look for loopholes and vulnerabilities as I skim through it.

Somehow, for all the attention to minutiae in the guidelines, everything ends up just slightly wrong by the time it gets put together at an airport. Even if we accept some form of passenger screening as a necessary evil these days, today's checkpoints seem like case studies in basic usability failure designed to inflict maximum frustration on everyone involved. The tables aren't quite at the right height to smoothly enter the X-ray machines, bins slide off the edges of tables, there's never enough space or seating for putting shoes back on as you leave the screening area, basic instructions have to be yelled across crowded hallways. According to the TSA's manual, there are four models of standard approved X-ray machines, from two different manufacturers. All four have sightly different heights, and all are different from the heights of the standard approved tables. Do the people setting this stuff up ever actually fly? And if they can't even get something as simple as the furniture right, how confident should we be in the less visible but more critical parts of the system that we don't see every time we fly?

There was a nice column by Randall Stross in the New York Times a few weeks back entitled "Theater of the Absurd at the T.S.A." []. (Unfortunately, the Times' perversely inverted pricing structure -- in which fresh news is free and old news is charged for -- means that the article may no longer be available on their free site by the time you look for it, but that's another subject for another day.) Anyway, the piece focuses on the ongoing plight of Christopher Soghoian, a computer science graduate student at Indiana University who has found himself in hot water for making available a web-based tool that creates visually convincing -- but entirely fake -- airline boarding passes. Soon after the site went online the FBI raided his home and shut down his site, but ultimately decided against filing any criminal charges. But the Transportation Security Administration isn't so sure. In spite of the FBI's declining to prosecute, the TSA is, as of this writing, apparently considering pursuing tens of thousands of dollars in administrative penalties against Mr. Soghoian. Bruce Schneier and I were both quoted in the Times piece, with the two of us suggesting that openness, rather than threats of fines and prosecution, would be a far better strategy for improving security here.

Does this mean I think putting the boarding pass generator online was a great idea? No, and in fact I have some serious reservations about it. But if Mr. Soghoian may have been guilty of a bit of poor judgement here, the TSA's behavior in response has been far, far worse -- and suggests problems much more damaging to our security than forged boarding passes.

I've finally decided to join the late 1990's and so have added a blog format to this site. Thanks to Jutta and the Questionable Utility Company of Northern California for nudging me forward with a nicely minimalist, intuitive interface where I can actually control system functions with shell commands, edit regular text files with regular text editors, and generally understand what's going on. (Before you ask: sorry, the software isn't yet available).

If it works out, I expect to publish most of my non-academic-paper-style writing here.

For a variety of reasons (spam, net kooks, and so on), I've decided against including an "add a comment" feature, at least for now. So if something I write so infuriates you that you simply must respond, you'll need to get your own blog to do it.