# Hmk2Sol - CIS 3362 Homework#2 Solutions 1 Using the index...

This preview shows pages 1–2. Sign up to view the full content.

CIS 3362 Homework #2 Solutions 1) Using the index of coincidence test, the best match is for the keyword length of 9. (Here are the IofCs for each of the bins: 6.15%, 7.5% 5.55% 6.3%, 6.0%, 9.15%, 6.6% 6.19% and 7.14%.) Once this is determined, visually inspecting the letter graphs allows you to try to get each of the 9 graphs to line up. In particular, the absence of J, Q, X and Z in most of the English language is probably the best way to line up these graphs. Once you line up the first few and get the keyword letters "HURR" it's a plausible guess that the keyword is indeed "HURRICANE". Here is the decrypted message: I figure it is time I hide a prize. I hope no one works on this problem right away because I have yet to buy the prize. But I will have it by Thursday of this week for sure. That is the eleventh of September so I am unambiguous. The prize will be hidden near the health center in a circular area. I will dig a little spot for it. The spot will be on the outer edge of the soil and it will be on the easternmost spot of the circle . Good luck! 2) For this one, the index of coincidence test was a little last definitive. Still, based on some of the very high numbers, the best match is a keyword length of 7 (Here are the IofCs for each of the bins: 4.39%, 9.14%, 10.85%, 6.46%, 8.78%, 6.21% and 5.64%.) Once again using the same technique with each of the bar graphs (lining up all of the "missing spots") we get the keyword, "KNIGHTS". The only tough bin is bin number three because for some bizarre reason, there are hardly any Es in this sample! Here is the plaintext: In two weeks the UCF football team is traveling to Boston to play BC. Last year we

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 4

Hmk2Sol - CIS 3362 Homework#2 Solutions 1 Using the index...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online