Information Technology course materials



Velammal College of Engineering and Technology, Madurai.

Department of Information Technology

ASSIGNMENT -I

YEAR/SEMESTER: IV/VII

Subject Code & Name: CS6701/Cryptography & Network Security

Questions

1. Find 11 13 mod 53 . [K3 –Apply] (CO1)

2. Find 321 mod 11 using Fermat’s theorem. [K3 –Apply] (CO1)

3. Using Euclidean algorithm calculate GCD (21,300) & GCD (125, 20) [K3 –Apply] (CO1)

4. Find GCD of (1403, 1081) [K3 –Apply] (CO1)

5. Explain Fermat’s little theorem and solve the following [K3 –Apply] (CO1)

(i) 15 18 mod 17 (ii) 5 27 mod 13

6. In a Chinese remainder theorem n=210, n1=5, n2=6 n3=7 and compute j -1 (3, 5, 2) i.e. given

x1=3, x2=5,x3=pute x. [K3 –Apply] (CO1)

7. Find gcd(1970, 1066) using Euclid’s algorithm. [K3 –Apply] (CO1)

8. Decipher the following cipher text using brute force attack: [K3 –Apply] (CO1)

CMTMTOOEOORW (Hint: Algorithm – Rail Fence)

9. Encrypt the following using the play fair cipher using the keyword MONARCHY. “SWARAJ IS MY BIRTH RIGHT”. Use X for blank spaces. [K3 –Apply] (CO1)

10. Encrypt the message “PAY” using Hill Cipher with the following key matrix and show the decryption to get the original plain text. [K3 –Apply] (CO1)

[pic]

11. Apply Caesar cipher and k=5 decrypt the given Cipher text “YMJTYMJWXNIJTKXNQJSHJ”.

[K3 –Apply] (CO1)

12. Apply Vigenere cipher; encrypt the word “explanation” using the key “leg”. [K3 –Apply] (CO1)

Submission Date: 08.08.2017

Course Incharge Module Coordinator Verified By

Mr.P.Suresh Babu Dr.R.Perumalraja HoD/IT

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download