TU Wien:Network Security VU (Zseby)/Exam 2019-04-26 (SS19)

Aus VoWi
Zur Navigation springen Zur Suche springen

16 questions on 9 pages, 1 hour of time

  1. Decrypt this message (Caesar cipher, k=3). _ _ _ _ _ _
  2. One-time pad: Calculate ciphertext with message xor key
  3. One-time pad: Name 4 properties that a key has to fulfull
  4. Why is it a bad idea to use a One-Time-Pad twice?
  5. Explain ECB
  6. What can be used in an attack of ECB-encrypted messages?
  7. What are the signature functions for RSA?
    • Calculate the advantage for P(A(R) = 1) = 0.9 and P(A(G(s)) = 1) = 0.2
    • Can G be considered as a good PRG?
  9. What function can be used to find out how many numbers 1 <= x <= n are relatively prime to n? Calculate it for n = 21.
  10. Difference between MAC and Digital Signature?
  11. ECC Graph, R = P+P. Show result R of Addition in the graph (figure from slides)
  12. Sketch Diffie Hellman Key Exchange.
  13. IPSec Authentication Header (AH) provides (multiple choice)
    • [ ] Confidentiality only
    • [ ] Integrity only
    • [ ] both Confidentiality and Integrity
  14. TLS (multiple choice)
    • [ ] In TLS the TCP Port is not encrypted
    • [ ] Client auth optional
    • [ ] Can use DH for key exchange
  15. Which classifier is better? How do we now? (Note: Figure from slide regarding "Support Vector Machines (SVMs)")
  16. What can be done if you only have a technique to learn a linear classifier but the data is not linear separable?
Abgerufen von „https://vowi.fsinf.at/index.php?title=TU_Wien:Network_Security_VU_(Zseby)/Exam_2019-04-26_(SS19)&oldid=121212“