i’m in ur protocolz, jammin ur cellphonez

Krish Eswaran sent me a story about how a group at Virgina Tech described how LTE networks are susceptible to a certain kind of jamming strategy:

“An example strategy would be to target specific control or synchronization signals, in order to increase the geographic range of the jammer and better avoid detection,” the Wireless @ Virginia Tech research group said in a filing (PDF) submitted to the National Telecommunications and Information Administration. “The availability of low-cost and easy to use software-defined radios makes this threat even more realistic.”

Color me unsurprised! For my PhD, I studied arbitrarily varying channels (AVCs), which are information-theoretic models for communication against adversarial interference. There are a couple of design insights one can distill from considering the AVC model:

  • Separating protocol and payload makes schemes susceptible to spoofing.
  • Lack of synchronization/coordination between sender and receiver can be a real problem in adversarial settings.

Here we have a case where the protocol is easy to spoof/disrupt, essentially because the control information in unprotected.

This separation between control information and payload is often suboptimal in other senses. See, for example, Tchamkerten, Chandar and Wornell.

Linkage

I’ve been refraining from talking about the Dharun Ravi case, because it’s pretty complicated. On the one hand, after reading the New Yorker article and other material, it’s pretty clear Dharun is a grade-A jerk. And Tyler Clementi’s death was a terrible tragedy. But on the other hand, 10 years in prison is a serious thing, as Ta-Nehisi Coates points out. Ashvin shared a link to a blog post on “Deporting Homophbia”:

I have been Tyler and Dharun in a post 9/11 U.S. that accuses white men of exploiting the rest of the world and accuses brown men of destroying it. I have been Tyler and Dharun in a post 9/11 world where white men advocate for homosexual rights and advance homophobia and where brown men are understood as always homophobic. I am being presumptuous, so let me stop.

It’s an interesting take on things, and has made me think about the media coverage of the event and if and how Dharun’s race has played into how the story has been told.

Via Kamalika I learned about a lawsuit against IMDB.

A gem from SMBC via Cosma. The Beef Tensors are a nice touch.

Sepia Mutiny is shutting down, and Amardeep has some closing thoughts.

We always get to hear these stories about how service providers needs differential pricing for network traffic because they can’t make money, but then stories like this make me question the integrity of the complainers.

I heard Of Monsters and Men on KEXP and their show is sold out in Chicago, boo. Here’s their crazy video though:

Facts, “facts,” and ficts

After reading and hearing about The Lifespan of a Fact, I was primed to learn from TPM that the This American Life story involving Mike Daisey’s “trip” to see Apple’s products being made at Foxconn was retracted due to significant fabrications by Daisey, resulting in a episode entitled Retraction going into it:

When the original 39-minute excerpt was broadcast on This American Life on January 6, 2012, Marketplace China Correspondent Rob Schmitz wondered about its truth. Marketplace had done a lot of reporting on Foxconn and Apple’s supply chain in China in the past, and Schmitz had first-hand knowledge of the issues. He located and interviewed Daisey’s Chinese interpreter Li Guifen (who goes by the name Cathy Lee professionally with westerners). She disputed much of what Daisey has been telling theater audiences since 2010 and much of what he said on the radio.

Linkage

I’m heading off to Mexico in less than 12 hours for a week during which I hope to disconnect : no email, web, or phone. I guess I’ll miss the majority of the post-Bin Laden news cycle. In the meantime, here are some more links because I am too lazy to post content.

Speaking of 9/11, this is simply terrible.

An interview with George Saunders, one of my favorite authors.

Blackwell’s proof of Wald’s Identity, as told by Max.

Long pepper looks fascinating and tasty!

Can Voter ID Laws Be Administered in a Race-Neutral Manner? The short answer is no. The longer answer is a 30 page paper.

Frank has blogger about our trip last weekend to The 2nd 8th Annual Grilled Cheese Invitational. My arteries may never be the same again.

There are no more typewriter factories. This makes me especially sad, as I have a 1914 Underwood No. 5 that I love (and lug).

Instant Runoff Voting, STV, AV, and the like

One thing I’ve gotten interested in lately is Instant Runoff Voting (IRV), which is an alternative vote tabulation system to our “first-past-the-post” system here in the US. It’s also known as the Alternative Vote (AV), and in multi-winner elections, the Single Transferrable Vote (STV). I’ll probably blog a bit on-and-off about this topic, but for starters, there’s a lot of activism/partisanship when it comes to promoting different voting systems. Unfortunately, almost all voting systems under consideration fall victim to Arrow’s theorem, which says, basically, that you can’t have a method of aggregating people’s preferences that satisfies a bunch of desirable criteria (under some assumptions on how preferences are given).

IRV or STV is used to elect Representatives in Australia, and the Australian Electoral Commission has a nice video explaining the process. It also mentions the election monitors, which are called scrutineers. That always cracks me up. But I digress. AV has come up more recently in the UK, where people are thinking of using it for Parliamentary elections. The pro-AV side has its videos as well, which seem designed to appear to the beer-lovers out there. However, the polling on its popularity seems to indicate that the switch to AV will not happen. There’s opposition to AV from different sources, and even some small parties don’t think it will make a difference.

I’ve gotten interested in IRV because it’s used in California for some local elections. The recent mayoral election in Oakland was run via IRV, which requires a bit of voter re-education. The outcome of the election was quite interesting, wherein Don Perata, who won the largest share of first-choices, ended up losing because Rebecca Kaplan was eliminated and the second- and third-choices went to Jean Quan. This is exactly the kind of thing proponents of IRV want.

What is less clear is how the mathematics of counting IRV works, and how sensitive the counting process is to errors. A lot of people have written about the former, but there has been less work about the latter, and that’s something I’ve started working on, because auditing the outcome of elections is an important step in ensuring voter confidence in the results.

UPDATE: As Oxeador points out below, Arrow’s Theorem is actually a statement about producing a total order of all the candidates that satisfies a given set of criteria, not about single-winner elections. In particular, if you treat the IRV ordering as the order in which the candidates are eliminated, then IRV would fall under Arrow’s Theorem.

Linkage

Yes yes yes, all my posts are link posts now. I swear, I’ll get back to something more interesting soon, but I always promise that.

People post funny things to ArXiV.

Razib discusses new studies of the genetic origin of Indians.

Tips for food photography. I seem to know several food bloggers now.

A new study about bullying.

The University of Michigan is allowing longer tenure processes. This is in part to address the pressures of getting tenure and starting a family at the same time, but also particularly the culture in the medical school, where “very few faculty in medical schools actually take advantage of such policies [to halt the tenure clock].” The academic Senate Assembly was opposed to the change.