Blog Archives: April, 2009
Trip to Florida
Waves and the pier at Fort Lauderdale beach My parents and I went to Florida for New Year’s this past year and spent a few days in Fort Lauderdale before taking off on a Caribbean cruise. It was the first time (that I can remember) that we went away around Christmas or New Year’s, and let me tell you, arriving in Florida and walking on the beach was absolutely fantastic!
Green iguana hiding in the shrubs 
Portuguese man o' war, closeup One of the neat things that happened while I was there was seeing some interesting animals. The beaches were covered with Portuguese man o’ war (which, I learned, are not jellyfish), so you had to be careful walking (it was too cool for me to swim, anyway). And at our hotel we saw a cute little green iguana wandering around as well.
Queen Mary 2 arriving at Port Everglades early in the morning After spending a few days with our friends the Peters Family, they left for a 24-hour sprint up the I-75 back to Windsor and we got ready for our cruise on the Queen Mary 2, which you can see arriving early in the morning in the picture at left. I will write more about our cruise later, as I start going through the hundreds of pictures I took throughout the Caribbean and on board ship.
View the rest of my 2009 Florida pictures.
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Dies Irae
If Hell is an abyss, then the music that will be playing as the damned fall into the abyss will be Dies Irae, from Verdi’s Requiem.
On Friday night I went to see the Queensland Orchestra and a 300-voice choir give a performance of Verdi’s Requiem. The most stunning piece in Verdi’s Requiem is by far the Dies Irae, the “Day of Wrath”, which has such uplifting lyrics as “A day of wrath; that day, it will dissolve the world into glowing ashes” and “So when the Judge is seated, whatever is hidden will be made known: nothing shall go unpunished.”
Give a listen to Verdi’s version, which can barely be appreciated by this poor quality recording on YouTube, or just wait until the apocalypse where this will surely be playing loud and clear. (Mozart’s Dies Irae is probably the more famous Dies Irae, and the one that I knew before going to the concert, but Verdi’s is by far more terrifying.)
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Running – Week 4 – Hungry
This was a tougher week for running for me. The weather and schedule was unfriendly — Wednesday’s rock climbing was rained out, Thursday’s run was postponed to Friday due to a meeting, and Sunday’s run was in 25°C sun. I’ve been hungry all week which means that I probably haven’t adjusted to the amount of food I need to be eating in order to be running regularly. I’ll have to figure out a way to eat more and find some healthy snacks.
Which reminds, it’s time for dinner!
| Apr 20 Mon | Rest day | |
| Apr 21 Tue | 3.5km | Easy run |
| Apr 22 Wed | Rest day (rock climbing was rained out) | |
| Apr 23 Thu | Rest day | |
| Apr 24 Fri | 8.0km | Tempo run: warm-up, 4km @ 11.5km/hr, cooldown |
| Apr 25 Sat | XT | Bouldering; 10km biking |
| Apr 26 Sun | 11.4km | Long run |
| Total | 23.0km | Year to date: 127.3km |
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Denial of service paper
SU09 I’m pleased to announce that some of the work that appeared in my PhD thesis has recently been accepted to a conference. My work with fellow University of Waterloo student Berkant Ustaoglu (now a postdoc at NTT in Tokyo) on denial-of-service-resilient key agreement protocols will be presented at the 14th Australasian Conference on Information Security and Privacy (ACISP) 2009 which is being held here in Brisbane in July, and the proceedings will be published in Springer’s Lecture Notes in Computer Science.
Denial of service attacks are where an attacker tries to consume all the resources that a computer, such as a web server, has available — filling up all of its memory or overloading its processor, for example. One of the most expensive operations that a web server performs is the cryptographic key agreement protocol, where it sets up a secure channel between the user’s computer and the web server.
Before doing expensive operations like cryptography or database lookups, a server could request that the user “prove” it’s not trying to cause trouble. One way of doing so is to give the user’s computer a puzzle to solve, something that might take the user’s computer a couple of seconds of hard work to solve, but the solution to which can be verified instantaneously by the server. This way, an attacker has to do a lot of work to create many requests to overload the web server, but a normal user is not too burdened by this requirement. These techniques have been known for some time, but how they should be used has only been studied in an ad hoc fashion.
Our work develops a formal mathematical model for how cryptographic communication protocols should try to resist denial of service attacks by using puzzles, similar to the formal mathematical models for the confidentiality of key agreement. We give a protocol that achieves these goals, and more importantly our framework could be used by many protocols to describe their denial of service resistance properties.
The main project I am working on during my postdoc here at QUT is further studying how to model denial of service, so this paper has been a great start to my work down here.
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Half marathon training – week 3 – it begins?
As I mentioned in a previous blog post, I plan on running a half marathon in August here at the Brisbane Marathon Festival, and then will also be running in the GoodLife Fitness Toronto Marathon in October (though I have no idea yet whether I’ll be stupid brave enough to run in the full marathon or not).
This was week 3 of my half marathon training program (based on the Runner’s World SmartCoach Training Program). The program mostly calls for three runs a week — an easy run, a tempo or speedwork run, and a long run, with increasing distance over time.
Where were weeks 1 and 2? Well, I did start my training program a few weeks ago but was not able to fully follow the program due to weather here in Brisbane and me not waking up at 7am to go running. I don’t have too much control over the former, but I’m getting better at the latter, and as winter comes around I won’t need to worry about the latter as much either since it will be cooler longer.
As Cecilia does, I will be recording some of my training progress on here, mostly to keep myself going at it.
| Apr 13 Mon | Rest day | |
| Apr 14 Tue | 3.2km | Easy run |
| Apr 15 Wed | XT | Rock climbing |
| Apr 16 Thu | 8.0km | Speedwork: warmup; 2x1600m w/800m jog; cooldown |
| Apr 17 Fri | Rest day | |
| Apr 18 Sat | Rest day | |
| Apr 19 Sun | 10.0km | Long run |
| Total | 21.2km | Year to date: 104.4km |
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Twilight 10km results
Results from the Twilight 10km race are available. Unfortunately, the timing system didn’t record times based on my chip, only my gun time (49:24.3). (Gun time is from when the race starts until when you cross the finish line; chip time is from when you cross the start line until when you cross the finish line. Gun time is greater than or equal to chip time, since in big races there are usually people in front of you and it can take a few minutes to actually get to the start line.)
According to my watch, my chip time should have been 48:19, which would place me 128th out of 762 overall and 31st out of 151 in the male 30-39 category.
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Thesis analysis
When I was writing my PhD thesis, I kept my thesis in CVS. For my non-technical readers, that’s a form of revision management software, which lets you keep track of your document as it changes over time. That allows you to fix something if you realize you want to go back to a previous version, it allows you to create diffs (like Microsoft Word’s track changes) between any versions of your document, and it also means you can analyze the history of your document.
Thesis analysis Inspired by something I once saw on another blog, I wrote some scripts to find out statistics of my thesis over its lifetime. In the graph at left (click it for a larger version), the green area represents the total number of pages over time, and the the blue bars represent the number of lines of code changed each day. In other words, the green represents the overall picture and the blue is the amount of work done each day.
I was most interested to discover that my thesis work happened in chunks with long breaks in between. As you can see I worked on my thesis over a period of 6 months before submission on January 22, 2009, but in that six month period only about 55 days were actually spent editing my thesis. Rather than slacking off, what really happened is that I was working on turning the research into papers that eventually turned into thesis chapters. So a lot of work would happen outside the thesis for a few weeks and once that was done there would be a flurry of activity to bring it all into the thesis.
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Easter food
Aside from going to church, Easter (like most holidays) in the Stebila house involves food. (Is it a coincidence that one of the main Easter weekend services at the Ukrainian Catholic church in Windsor is a blessing of the food?)
For Easter, there’s chocolate, of course (though my father seems to eat more of it than I do). And my mom always makes wonderful meals. So this year in Brisbane I decided to try my hand at an Adele Stebila-style Easter. Breakfast is a delicious and thoroughly unhealthy concoction called Hungarian Bubble Ring, which consists of little sweet dough balls coated with butter, rolled in cinnamon and sugar, and topped with raisins and maraschino cherries. I didn’t get her recipe in advance, so I had to make do with one I found on the Internet, which was a first-order approximation at best. Not nearly as tasty. But come to think of it, I probably didn’t put nearly as much butter or sugar in to mine than she must, so that could explain it.
Lest you think you were safe after the heart-attack-inducement adventure of breakfast, dinner involves pyrogies. I’ve written about pyrogy making before and even posted the world-famous Stebila family pyrogy recipe online. My pyrogies this time around were the best they’ve been so far, I think. I still fought with the dough more than I would like, and didn’t have quite enough filling, but by and large they were successful.
Fortunately for me, I don’t have to feel guilty about eating all this food: I ran 12km this morning for my long run, so I’d earned my meal. Hope your Easter was as tasty as mine!
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