Solving Geocaching Mystery Caches with Software

[ThomasChr]

• Speaker: NEEDED
• Duration: ?
• Description: This is a talk suggestion! I'm a geocacher and go out in the woods to find little plastic boxes. As strange as this already seams, it's getting stranger: Some of them require solving complicated Riddles:

GC7RKBW: Coding a program which extractes letters according to a coding sheme from a text
GC6834E: Given a SHA1 Hash, generate the correspondending Coordinates for it (bruteforcing)
GC7WATW: Solving a few simple Questions about the Internet and changing the User-Agent with Curl to get the coordinates
GC7Y888: Bruteforcing all combinations to solve an extra big "Haus vom Nikolaus" to get to coordinates
GCB0A4: Calculate the shadow of a tower (with given coordinates) at a specific time of the year, the coordinates are the tip of the calculated shadow
GC1G66E (archived): Solve the source code written in the esoteric programming language Shakespeare
GCG4ER (archived): Calculate prime factors for big numbers

(To be honest, I'm stuck at GC7Y888 right now :-) )

There are tons of those IT riddles out there. Even if you don't go out to get the boxes, you create simple neat programs to solve them.

If you want to take a look you need to register at geocaching.com and enter the (so called) GC-Number in the search field. If needed I can provide an account with all access rights (some caches can only be seen if you are paying) for research purposes.

And now I go back to write a python object-oriented program to solve the big "Haus vom Nikolaus" Riddle!

[ThomasChr]

Example for the "calculate the shadow" cache:

The dormouse had the look on the chimney of the electricity supplier of Erlangen early in the morning of May 26th; it was just 19 Minutes and 38 Seconds after sun-rise.
From these data it is possible to calculate the position of the Cache using the angles under which the sun appears.
The chimney (you can see its picture below as it appeared to the dormouse) is 140 meter high. You find the cache if you locate the shadow of the peak of that chimney just 19minutes and 37seconds after sunrise on May 26th of 2002. At that time sun is still close to horizon - so the shadow is quite a few kilometers from the chimney. If you use an algorithm defined in the german industrial standard (DIN 5034) to calculate azimuth and sun height you will be very close to the cache.

[blanky0230]

Exciting Example!