Due: Thursday, November 11, 2021, midnight (Thursday at midnight)
Problem 1: Substution Cipher Decryption
Break the letter-substitution cipher in part (a) of the puzzle box on page 210 of the reader. In case you want to write programs to break the code, you can cut and paste the following text:
LESTX KQLEY TQOJX ZEHYT QJQKL IQHST XAALY EXYSE SRYPH LJYPG QYTXK QVLKK QHGLY TYTQQ EHRXV GXJBR SEHSE XXFPR BQKKE XJPQY SHJPA SJQRS EHPTX KQGLY TEXYT LEOLE LYYXR LYHXG EXEXJ YXQSY LYGSR STXAA LYTXK QSEHY TSYBQ SERDX BVXJY
Hints:
- The most common letter in the ciphertext does not correspond to
E. - Remember, there are no spaces in the ciphertext – the 5-letter "words" above are simply to make it easier to copy. In other words, you can think of the above ciphertext as one long line of characters.
Problem 2: Transposition Cipher Decryption
a. Read the Wikipedia article on transportation ciphers.
b. Decipher the following message, which is encrypted using a "Route Cipher" with the following features:
- The 70-character plaintext was written into a 10-wide and 7-high grid
- It was encrypted with the pattern, "starting at the bottom left, read letters diagonally down and to the right. After reading a diagonal, start at the next row up, and read it down and to the right, etc."
DUDEN EEVAS ETERE GVYRO RNIEO GUTEV RUONY VEGDN DOEYO ONAUR ONWAN GUNNR OUANN PLNNA
Hint: Start by creating a grid of 10 across and 7 down, and then read off the ciphertext into the grid. Without a grid, this is tricky to get correct!