Reply To: Challenge 10B
@Bookluvr18
If you already understand how the cipher works, you don’t actually need Python to finish it. Coding just automates the mechanical part.
You can use Excel/spreadsheet for this as well. I haven’t personally done it, but I’d imagine you can put the two card grids and two letter grids into tables, split the ciphertext into two columns with one card per column, and use MATCH to find each card’s row/column index, then INDEX into the letter grids to get the plaintext. Drag the formulas down and you should hopefully decipher the text.
Alternatively, you can also just use a simple text editor and find and replace once you know some mappings like 7C -> R, XS -> E, etc. It’s not the most elegant, but it does work.
Also came across a useful page which has some nice techniques on using Excel to decrypt ciphers with known keys: https://www.get-digital-help.com/basic-substitution-cipher/#22
It’s not specific to this challenge, but you might find some of the lookup/replace ideas useful. Well done for making it this far and I hope you manage to solve it before the deadline!