CS 417 Exam 3

Spring 2008

    Part I – 30 Points

  1. 6 points
    What are the three factors of authentication?
  2. 6 points
    When you request a service via Kerberos, you are presented with a ticket. What does this ticket contain and how is it used?
  3. 6 points
    How would you check that a digital certificate is valid? Specifically, explain how you ensure that it (a) has not been modified and (b) is really issued by the party that claims to have created it?
  4. 6 points
    How does the steganographic technique of chaffing and winnowing use digital signatures?
  5. 6 points
    Is the following statement true or false? Explain and defend your position.
    Application proxies were once useful but have been rendered obsolete with the introduction of SPI (stateful packet inspection) firewalls as successors to packet filters.

    6. PART II – 28 points – 4 points each

    Define each of the following terms. You may omit one question. Please clearly indicate the question you choose to omit.

  6. Worm
  7. Rootkit
  8. DMZ
  9. Tunnel
  10. Heartbeat network
  11. Warm failover
  12. Distributed lock manager (DLM)
  13. Cascading failover

    14. PART II – 42 points – 3 points each

    For each statement, select the most appropriate answer. You may omit one question. Please clearly indicate the question you choose to omit.

  14. MS-CHAP, Microsoft's Challenge Handshake Authentication Protocol is most similar to:
    (a) Challenge-Response.
    (b) RSA SecurID.
    (c) Password Authentication Protocol (PAP).
    (d) SKID.
  15. Which of these authentication protocols is most vulnerable on insecure networks?
    (a) CHAP (challenge handshake authentication protocol).
    (b) PAP (password authentication protocol).
    (c) SecurID (SASL).
    (d) Kerberos.
  16. A digital certificate contains:
    (a) a signed public key.
    (b) a signed public key and encrypted private key.
    (c) an encrypted private key.
    (d) a signed private key.
  17. How does SSL establish an encryption key between the client and server?
    (a) The client picks the key, encrypts it with the server's public key, and sends it to the server.
    (b) Each machine uses the other's public key: the client encrypts data with the server's public key and the server encrypts data with the client's public key.
    (c) Diffie-Hellman key exchange allows the client and server to come up with a common key.
    (d) A trusted third party employing the wide-mouth frog protocol is used.
  18. CAPTCHA relies on
    (a) presenting the user with a series of questions.
    (b) a combination of biometrics and public key cryptography.
    (c) having the user prove that he/she has the correct key.
    (d) human pattern recognition.
  19. Which authentication scheme does not use a nonce for authentication?
    (a) Challenge-Response.
    (b) SKID.
    (c) Kerberos.
    (d) SSL.
  20. SecurID is vulnerable to:
    (a) man in the middle attacks.
    (b) dictionary attacks.
    (c) known plaintext attacks.
    (d) replay attacks.
  21. A packet filtering firewall cannot:
    (a) block packets from the Internet whose source address is masqueraded to appear as if it is from your internal network.
    (b) allow TCP/IP packets to port 25 on your mail server and disallow all other packets.
    (c) block attempts to create a buffer overflow attack to the mail server.
    (d) block all UDP/IP packets from the network 128.6.0.0/16.
  22. TCP/IP uses the following for fault tolerance:
    (a) heartbeat network.
    (b) information redundancy.
    (c) time redundancy.
    (d) physical redundancy.
  23. RAID 5 (disk parity) uses the following for fault tolerance:
    (a) heartbeat network.
    (b) information redundancy.
    (c) time redundancy.
    (d) physical redundancy.
  24. RAID 1 (disk mirroring) uses the following for fault tolerance:
    (a) heartbeat network.
    (b) information redundancy.
    (c) time redundancy.
    (d) physical redundancy.
  25. SYN flooding will cause a machine to:
    (a) go out of service.
    (b) not be able to accept any more incoming IP packets.
    (c) not be able to accept any more TCP/IP connections.
    (d) not be able to accept any more TCP/IP connections on a specific port.
  26. The two army problem guarantees that two users with an unreliable communication stream between them can achieve agreement:
    (a) by sending a message and receiving an acknowledgement.
    (b) by a three-way handshake: send a message, receive an acknowledgement, and then acknowledge that acknowledgement.
    (c) by applying error-correcting codes to the message.
    (d) never.
  27. An hypervisor would not:
    (a) allow multiple operating systems to run concurrently on one processor.
    (b) detect the installation of a rootkit within the operating system.
    (c) control the processor's memory management unit (MMU).
    (d) intercept privileged processor instructions that would normally go to the operating system.
  28. The main difference between a grid and a conventional HPC cluster is that a grid:
    (a) offers fault tolerance as well as high performance.
    (b) requires all machines to have the same operating system.
    (c) can be thought of as a virtual cluster instead of using machines dedicated to the cluster.
    (d) does not require processes to communicate with each other.