today was my first day of my new job as a software engineer at dybuster, a small zürich based software company producing learning software treating dyslexia and dyscalculia.
quite a different job than before, but still a very nice and friendly environment, and a very noble objective in my opinion :-)
today i was in bad säckingen to give a talk at the kinderuni (children university) hochrhein, a eu-funded joint project between the two cities bad säckingen in germany and stein (ag) in switzerland. in the talk, i tried to explain kids, age 8 to 12, a bit about cryptography.
starting with caesar-type ciphers and more general substitution ciphers, i then continued to explained how to crack such ciphers using frequency analysis. this included a live demonstration, which was quite fun thanks to all the contributions from the audience. after shortly giving hints on how to improve on ciphers, i quickly presented the advanced encryption standard before continuing with the second part of the presentation: public key cryptography.
i began by explaining the situation: two cats want to communicate / exchange something (like cat food :-) ), while a third cat is watching / able to intercept (eat). after mentioning diffie and hellman, i continued with a more practical example: a simple massey-omura three-pass protocol type exchange using a box and two padlocks. this was another great thing, asking the kids how they think this could work after presenting the box and the padlocks. and the sudden murmur of understanding when the second lock got added to the box and the box was sent back.
afterwards i asked the kids how they think this system could be attacked, and they both came up with the bruteforce (crack the box open) and the more tricky (man-in-the-middle attack) variant. great!
the last slides on factoring-based crypto and elliptic curves were quite hard to comprehend, as i knew beforehand, but at least they now know that there’s more out there for which they have to learn more about mathematics :-)
if you’re interested, you can download the slides here.
last week, we visited the säntis, one of the highest landmarks in northeastern switzerland. despite being quite crowded – after all, it was on a sunday with good weather – it didn’t feel too crowded on the top, and we caught some great views onto germany, lake constance, liechtenstein and austria. (i’m not sure whether we also saw france or italy due to haze. but in theory, we could have.) enjoy some of the views and panoramas:
more than one year ago, miukumauku, my cat, moved in with us. so when i was sitting outside and saw her playing in the sun, i had to take some pictures. she grew quite a bit, and stopped playing with most of her toys, in favour of having a real-life outside, playing with anything that moves and is not too big. and she’s still extremely cute.
here are some pics from today:
recently we were in knie’s kinderzoo in rapperswil. judging from the huge amount of families, apparently a very attractive destination. and from judging the kids, they seem to like it a lot. here are some impressions:
the interplay of sunlight and clouds sometimes results in interesting shots… some days ago, parts of the sky was cut in two pieces:
sometimes, we can observe quite dramatic sky panoramas:
this weekend, the apv zo visited the wildpark bruderhaus in winterthur. the weather was great, and except for the lynxes, we saw all animals we planned to see: sika deer and fallow deer, european bisons, wild boars, red deer, przewalski’s horses and gray wolves.
