In Chapter 2, Jen mentions she uses a Playfair cipher to crack the code imbedded in the footnotes. I tried this myself and was able to confirm it. You can find out more about it in this Wikipedia article
The keyword is GEMINI. So the Playfair square looks like this:
G E M I N A B C D F H J K L O P R S T U V W X Y Z
In this version (the one that works) you have to drop the 'Q'. When drawing your rectangles, you want to move one letter left or one letter up).
The keyword is GEMINI. So the Playfair square looks like this:
G E M I N
A B C D F
H J K L O
P R S T U
V W X Y Z
In this version (the one that works) you have to drop the 'Q'. When drawing your rectangles, you want to move one letter left or one letter up).