Homework 1.3 - Instructions All assignments must be typed...

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

Instructions: All assignments must be typed; no hand-written assignments will be accepted. You must name your file as: your_last_name_your_first_name_HW# Acceptable file formats: .doc, .docx, .pdf Inside the file, you MUST include your full name, otherwise your HW will not be graded. Do not just give answer. You must show your work. Otherwise you will not get any points CIS 3360 – Security in Computing Spring 2016 Homework 1.3 (50 points) 7) [10] Encrypt the message "COMPUTERSECURITY" using the Vigenere cipher with the keyword "BLUE". C O M P U T E R S E C U R I T Y B L U E B L U E B L U E B L U E (2 + 1) mod 26 = 3=D (14 + 11) mod 26 = 25=Z (12 + 20) mod 26 = 6=G (15 + 4) mod 26 = 19=T (20 + 1) mod 26 = 21=V (19 + 11) mod 26 = 4=E (4 + 20) mod 26 = 24=Y (17 + 4) mod 26 = 21=V (18 + 1) mod 26 = 19=T (4 + 11) mod 26 = 15=P (2 + 20) mod 26 = 22=W (20 + 4) mod 26 = 24=Y (17 + 1) mod 26 = 18=S ( 8+ 11) mod 26 = 19=T (19 + 20) mod 26 = 13=N (24 + 4) mod 26 = 2=C = D Z G T V E Y V T P W Y S T N C 8) [10]Encrypt the message "ITSCOOLGOINGTOSCHOOL" using the Playfair cipher and the keyword "ORLANDO".
Image of page 1

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

Key: O R L A N D B C E F G H I/J K M P
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Q S T U V W X Y Z IT SC Ox OL GO IN GT OS CH Ox OL KS X(I/J) LV RA PD ML KP LP B(I/J) LV RA =KSX(I/J) LVRAPDMLKPLPB(I/J)LVRA 9) [20] If a cryptosystem has 2 51 possible keys, and you have 800 computers, each which can try 400,000 keys a second, in how many days would you be able to recover the key, assuming that you can immediately recognize when you've attempted decrypting with the correct key? (Assume there are 86,400 seconds in a day.) (800 computers)(400,000 keys/sc/computer) = 320,000,000 (320,000,000 keys/sec)(86,400 sec/day) = 2.7648 x 10 13 keys/day (2 51 keys) / (2.7648 x 10 13 keys/day) = 81 days 10) [10] Given the input 1001011001011100 2 and the permutaTon table below, what would be the output be afer applying our input to the permutaTon table? (Please give your Fnal answer in the ±orm o± a binary number, not a permutaTon table.) PermutaTon table: 1 6 1 1 2 5 1 5 2 1 1 6 1 4 3 1 7 1 3 4 9 8 1 0 0 1 0 1 1 0 0 1 0 1 1 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 16 1 12 5 15 2 11 6 14 3 10 7 13 4 9 8 0 1 1 0 0 0 0 1 1 0 1 1 1 1 0 Output: 0110000110111100 2...
View Full Document

  • Spring '10
  • Guha
  • Cryptography, 81 days, 86,400 seconds, 86,400 sec, M P U T E R S E C

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern