First of all you need to visit this page and solve the puzzle. You don't have to solve the whole puzzle if you don't want to, but you need to find the 10 missing letters, which are part of the Treasure Hunt challenge.
For your ease, these questions have been marked with red.
Then you need to collect all the clues which are hidden among the sponsors.
Go talk to the sponsors and they will give you a magic QR code for you to scan.
Once you have all the QR codes and the 10 letters from the Crossword Puzzle, go find the Treasure Hunt Masters and they will help you figure out the upper case & lower cases letters so you can finish the game.
Then, you will be able to complete the game and enter the prize draw which will take place during the closing remarks, at the end of the conference.