$ curl -Dh t.oxi.city > ph2k15

author: Hannah Earley

This was the promotional puzzle we used for the 2015 puzzlehunt, and which was distributed on the posters and flyers.

1. There are a few things to notice initially:
   1. The green shape appears to be fractal, and indeed it is, you may immediately recognise it as a Koch snowflake though searching for fractals should also identify it.
   2. The blue text circumscribing the snowflake repeats twice.
   3. There is a cat in the centre, but this is not part of the puzzle just a stylisation of the CUCaTS logo.
   4. There is also some kind of barcode pattern on the inner edge.
2. How can we link these things together? Inspecting the circumscriptial text further, we find it is in fact a perfect pangram (alternatively turn to Google). The fact that it circles the figure also suggests there might be a relation between it and the snowflake. We find that the 3 main lobes are divided into 9 smaller lobes, which are further divided into 27 even smaller lobes. We can then match the 26 letters to each, ignoring the apostraphe.
3. When we start matching letters to the lobes, we find that our initial assumption that it was a fractal was wrong, it's actually an imperfect fractal and there are some missing triangles. Specifically, the pattern of missing triangles involves six variable positions which can be on or off. We further find that each pattern is unique to each letter, and that the 27th lobe is complete explaining the 26-27 mismatch.
4. We have now linked two of the three parts. Inspecting the barcode further we find there are six rows. (It would also be helpful to notice the threefold symmetry now to reduce work later.) It would seem therefore that the 6-bit pattern we discovered earlier may be used to decode each column of the barcode. We also find that there are green columns interspersed between the barcode, suggesting that the 27th lobe is a space or punctuation character.
5. Applying the code we've found, we can finally get the full message, "we like the cut of your jib if this was too easy help us further at toxicity slash blaringeasygoingduck". During the leadup to the puzzlehunt, we used the website http://t.oxi.city/, explaining the text, and thus this revealed a secret webpage for a supply drop. Only one participant managed to make it this far! In this version of the puzzle, we will accept either the full message, "toxicity slash blaringeasygoingduck", the URL or just "blaringeasygoingduck".