CPSC 433 Data Security and Encryption Techniques
Final Test (Sample)
Multiple Choices (60%)
1.
What are the purposes of Key distribution center (KDC) - Select the one that is wrong?
a. Encrypts session key with secret keys to sender and receiver
b. New keys and less couriers for transactions
c. Encrypts session key with secret keys to receiver only
d. Shares secret key with users in network
e. Data Integrity - assurance that data received is as sent by an authorized entity
2.
Which one below about Public-key Cryptography (PKC) is wrong?
a. Public-key decrypts private-key and not vice-versa (private-key does not decrypts public-key).
b. If receiver’s public-key and sender’s private key are both used, both parties are authenticated
c. Computationally infeasible to deduce private-key from public-key
d. The most common public-key algorithm is RSA.
e. PGP uses PKC to Encrypts e-mails and files using “web of trust”
3.
Which one below about Digital signatures is wrong?
a. It uses with Hash function to calculation assigns hash value to message
b. It is quite possible the chance of collision is great.
c. Digital signature, hash function and encrypted message sent to receiver
d. We use Timestamping to solves non-repudiation problem
e. The Message integrity means to recalculate message hash value matches that sent in signature,
verifies integrity
4.
Which one below about Public-key Infrastructure (PKI) is wrong?
a. Integrates public-key cryptography with digital certificates
b. Integrates public-key cryptography with certification authorities (CA’s)
c. PKI will hold the keys generated unchanged to ensure communication integrity.
d. PKI will ensure authenticity via Check certificate with CRL or Online Certificate Status Protocol
(OCSP)
e. PKI and digital certificate transactions are more secure than phone line, mail or even credit-card
transactions
5.
Which one below about Playfair Cipher is wrong?
a. It is a 5X5 matrix of letters
b. if a pair is a repeated letter, insert a filler like 'X'
c. Does not need to use any keyword or key
d. if both letters fall in the same row, replace each with letter to right
e. if both letters fall in the same column, replace each with the letter below it
6.
Which one below about Digital Certificates and certification authorities (CA’s) is wrong?
a. Digital certificate: identifies user, issued by certification authority (such as VeriSign)
b. Policy creation authorities signs certificates for policy creation authorities
c. Policy creation authorities sign for CA’s who sign for individuals and organizations
d. Digital certificates stored in certificate repositories
e. Policy creation authorities sign for CA’s who sign for individuals and organizations
7.
What is(are) the purposes of Java Policy Files? (Choose the best one)
a. It granted permission on basis of security policy
b. It comprised of varying levels of access to system resources
c. system-wide policy loaded automatically by JVM
d. A and C
e. A, B and C
8.
Suppose you are developing a Java Applet, how do you do to perform digital signature? (Choose the right
one).
a. You must include the ActionListener interface
b. You must sign applets with digital signatures
c. You must grant the Applet with permission in your code
d. You must distribute your code separately
e. User will not see any actions or messages when Applet is loaded.
9.
Continue from question 8, how to perform digital signature in Java? (Choose the wrong one)
a. Java supports RSA-signed applets using Java JAAS
b. You must generate RSA keypair
c. You must export digital signature to file
d. You must sign applet’s JAR file with digital signature
e. You must add keys that you generated to keystore pool
10. Which statement below about Stream and Block Ciphers is wrong?
a. Stream ciphers process messages a bit or byte at a time when en/decrypting
b. Block ciphers process messages in into blocks, each of which is then en/decrypted
c. Block ciphers would need table of 264 entries for a 32-bit block
d. DES is one of the block ciphers that was commonly used before
e. Modern block ciphers involve substitution (S-Box) and permutation (P-Box) process.
11. Which one below about “Authentication” is wrong?
a. Authentication means to restrict access to certain aspects of a program
b. Authentication allows users to connect to a network
c. Authentication can ensure message get properly encrypted
d. Authentication regulates resources available to users on network
e. Java uses JAAS to perform Authentication process
12. Which one below about Java Java Cryptography Extension (JCE) is wrong?
a. It supports 3DES
b. It supports public-key algorithms like RSA
c. It customizable levels of encryption through multiple encryption algorithms
d. It customizable levels of encryption through one key size.
e. It provides Java applications with various security facilities
13. In Java Authentication and Authorization Service (JAAS), authentication is handled by (choose the best
one)
a. Kerberos system – which authenticates client’s identity
b. secondary Ticket Granting Service (TGS)
c. TGS authenticates client’s rights to access services
d. A and B
e. A, B and C
14. Which one below about Single Sign On scripts is wrong?
a. Workstation login scripts sends password to each application
b. The password of workstation login scripts is stored in server
c. Workstation login scripts authenticate users with central server
d. A, B are wrong
e. B and C are wrong
15. In Java Authentication and Authorization Service (JAAS), which one below is wrong?
a. user governs access to resources on user policies
b. group associates user to group, bases policies on group privileges
c. role-based security policies has default policies exist
d. users obtain privileges to needed applications based on intended task
e. user, group and role-based security policies can control the access in JAAS
Questions and Answers (40%) – please write your answer on the blank area of the test sheets.
Don’t spend too much time to write long answer for each question. Try to be as neat and short as
possible.
1.
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4.
5.
6.
What are the key process steps of SSL (Secure Socket Layer) in Java? (10%)
Please use a diagram and statements to represent and explain the infrastructure of Key Agreement
Protocol. (10%)
Please explain 5 steps of Digital Signatures for Java Code? (5%)
Please explain what are 5-steps of Authentication cycle? (5%)
What is the purpose of State Array in AES cipher? (5%)
What is the purpose of “Single Sign-on”? (5%)
- Good Luck to your test and happy summer vacation…