This program is a helper to solve geocache GCWD13. Run from the command line on a machine with Ruby installed (macs come with ruby pre-installed):
git clone https://github.com/caguthrie/tombraider_geocache.git
cd tombraider_geocache
ruby geo.rb
The program will prompt you for the secret key. Try the key you think is correct, and message will be translated. If you can read the whole message, you are correct!