A very simple book cipher encoder/ decoder for the command line
It will take an input file written in plain text, and will try to find the individual words in a key file. This can include: txt, pdf, epub, word or any other format supported by textract.
The key file needs to have all words mentioned that are also listed in the input file, or it will exit mentioning the word it can't find. If successful, a csv or binary output file is created with the references to lines and words from the key file. The original key file can then be used to decode the message.
Python and the textract package is required to run. to install textract visit: http://textract.readthedocs.io/en/stable/installation.html
to encode a message run: python encode.py example_key_doc.epub input.csv
to decode: python decode.py example_key_doc.epub out.csv
in order to use a binary output file (out.pcb) add '-b' as the last parameter on both commands, this will make the output file smaller in most cases and it will require something like a hex editor for examining it