My thinking behind this is that block ciphers can be used to obfuscate data, but cryptographic hash functions like MD5 and SHA-1 are also built from block cipher components. I’ve done quite a lot of research into hash functions and the MD5 algorithm in particular, but I’ve never actually studied the maths behind modern encryption schemes like AES!

The AES Wikipedia article is a pretty good place to start, but then things move on to heavy mathematical descriptions of cryptanalysis which just go straight over my head! However, stuck at the end of the article is a link to the aptly-named Stick Figure Guide to AES. It’s quite a long read but it’s by far the clearest explanation I’ve seen of the underlying mathematics. There’s even a bit of humour in there too! At the end of the guide (but before the comments) there are links to PDF and Powerpoint versions which might be better for offline reading. In short, it’s brilliant!

Despite the subject matter, it is surprisingly accessible (After all, it was my mother that recommended it to me!), but still contains enough technical information to keep a computer science student interested.

I read it again recently and even though five years have gone by since I first picked it up, very little of it seems dated. It’s definitely worth a read for anyone with an interest in computer-crime.

Traces of Guilt got me thinking about computer security from the “other side”, and is probably part of the reason that I’m studying computer forensics today.

Basically, the pigs are fed by a system that reads an RFID tag on the pig’s collar. The tag is read, the gate opens and the pig gets some food. The system tracks which tags have been read that day, so the pig should only get one meal. But some pigs don’t like wearing the collars and scratch them off, leaving them on the ground for a clever pig to pick up. If the clever pig has picked up an unread tag, it gets more food, if not it tries again.

Pigs defeating RFID-enabled feeding system.

Yes – I’m well aware that this post adds nothing of value to the Internet. Unless someone, someday wants to know what I thought of the first season of Battlestar Galactica, in which case I’ve provided them with a potentially life-altering piece of information. Maybe that’s the thinking behind Twitter?

No – I haven’t been getting much sleep lately…

The Japanese rail network is totally different! It’s spotlessly clean (even the Tokyo underground!) and runs to the minute. If the timetable gives a 14:03 departure, the train is leaving the station at 14:03:01.

Today I travelled to Kyoto on the Hikari high-speed train. The interior was set out more like an aircraft cabin than a train car, with everyone given an assigned seat in forward-facing rows. One very cool thing about that: The seats all face forward. What happens at the end of the line? Does the entire train turn around? Do the passengers just have to travel backwards instead? No. A team of cleaners rushes on board between services, and as part of their duty, spins each row of seats through 180-degrees! It’s brilliant!