Cipher-text of round 1:LHIEEIUESSCEPWMNDLAO Round 2: Now, we decide to go with a previous order that is 4,1,3,2. Cipher-text:EEENLESPICUMHISW These multi-round columnar techniques are harder to crack as compared to methods seen earlier. 3) Vernam Cipher (One-Time Pad) TheVernam C...