No shortage of tough challenges in PlaidCTF… Overall a very impressive competition, no wonder it’s considered to be one of the top CTF events. I guess mature CTFs all had enough time to polish their UIs and gain enough experience to make sure their events go smoothly and with few hiccups.

Some of the problems were very different from what I’ve seen in other CTF. I was especially impressed with Echo - that was a great fun to play with.

An interesting recurring theme in PlaidCTF is trivia-like problems that deal with known computation bugs. This time we were asked (in logarithms are hard) to compute e^(1.000000001), which is supposed to be 2.7182818 (unless you are a Texas Instruments calculator, in which case it’s 2.7191928 ).

Writeups:

zipper

Echo

Pykemon

Down the Reversing Hole