January 10th, 2008


"Steal This WiFi" by Bruce Schneier

Whenever I talk or write about my own security setup, the one thing that surprises people - and attracts the most criticism - is the fact that I run an open wireless network at home. There's no password. There's no encryption. Anyone with wireless capability who can see my network can use it to access the internet.

To me, it's basic politeness. Providing internet access to guests is kind of like providing heat and electricity, or a hot cup of tea. But to some observers, it's both wrong and dangerous.

I'm told that uninvited strangers may sit in their cars in front of my house, and use my network to send spam, eavesdrop on my passwords, and upload and download everything from pirated movies to child pornography. As a result, I risk all sorts of bad things happening to me, from seeing my IP address blacklisted to having the police crash through my door.

While this is technically true, I don't think it's much of a risk. I can count five open wireless networks in coffee shops within a mile of my house, and any potential spammer is far more likely to sit in a warm room with a cup of coffee and a scone than in a cold car outside my house. And yes, if someone did commit a crime using my network the police might visit, but what better defense is there than the fact that I have an open wireless network? If I enabled wireless security on my network and someone hacked it, I would have a far harder time proving my innocence.


I agree on pretty much all counts. The only precaution I would like to take is to limit the bandwidth available to unauthenticated connections to my wifi. And the only reason I care about that is because my Comcast "unlimited" service isn't actually unlimited. If I go over 200 GB of traffic a month, they start threatening to cut me off. Other than that, I have no problem sharing my WiFi. And it seems like about half of the 15 APs in my apartment complex feel similarly.

Jamie Hyneman on tech that sucks.

The MythBusters show is all about the crazy stuff that happens when technology meets man. In fact, we go out of our way to think of creative ways to play with technology. My MythBuster partner, Adam Savage, has just about every kind of iPod, iPhone and iPipewrench he can get his mitts on. But there are times when innovation produces aggravation, and when that happens, technology can flat out drive us nuts.


I totally agree with all of the observations in this article, but I'm extremely cynical that any of them will ever be fixed. Companies luuuuuuv to "lock customers in" and force them to buy their brand of battery, their charger, etc. It's bad engineering, and everyone (most of all the people creating these things) knows it. And they intentionally keep doing it over and over again anyway. Why? Because they're far more interested in profits than good engineering.

Optimizing Perl with Inline::C

was discussing with someone today about a time I used Inline::C to massively speed up an inner loop in a Perl program. Thing is, in that case the real speedup wasn't any super smart C programming on my behalf, it was just making use of a very optimised vendor library that you could only access from C.

So I got to thinking - in normal every day code, is there any real speed benefit to be had by writing your inner loops in C. I found an old web page by Mitchell Charity discussing Inline and, interpreting his (slightly pathological) example a little, I got a surprising result:

The C code was 48321% faster.