Cryptography Multiple Choice Questions on “Public Keys and X.509 Certificates”.
1. Public key encryption/decryption is not preferred because
a) it is slow
b) it is hardware/software intensive
c) it has a high computational load
d) all of the mentioned
Answer: d
Clarification: Due to high computational load ( thus being slow ) public key systems are not preferred for large cryptosystems and large networks.
2. Which one of the following is not a public key distribution means?
a) Public-Key Certificates
b) Hashing Certificates
c) Publicly available directories
d) Public-Key authority
Answer: b
Clarification: Hashing certificates is some I just made up. It doesn’t exist noob.
3. What is the PGP stand for?
a) Permuted Gap Permission
b) Permuted Great Privacy
c) Pretty Good Permission
d) None of the mentioned
Answer: d
Clarification: PGP stands for Pretty Good Privacy.
4. PGP makes use of which cryptographic algorithm?
a) DES
b) AES
c) RSA
d) Rabin
Answer: c
Clarification: PGP recommends the use of RSA.
5. USENET is related to which of the following Public Key distribution schemes?
a) Public-Key Certificates
b) Public announcements
c) Publicly available directories
d) Public-Key authority
Answer: b
Clarification: Many PGP users append their public key to messages that they send to public forums, such as USENET and Internet mailing lists.
6. Which of the following public key distribution systems is most secure?
a) Public-Key Certificates
b) Public announcements
c) Publicly available directories
d) Public-Key authority
Answer: a
Clarification: Public certificates are the most secure key distribution/management systems right now.
7. Which systems use a timestamp?
i) Public-Key Certificates
ii) Public announcements
iii) Publicly available directories
iv) Public-Key authority
a) i) and ii)
b) iii) and iv)
c) i) and iv)
d) iv) only
Answer: c
Clarification: Public announcements and Public Certificates involve the use of timestamps.
8. Which of these systems use timestamps as an expiration date?
a) Public-Key Certificates
b) Public announcements
c) Publicly available directories
d) Public-Key authority
Answer: a
Clarification: Public key certificates use timestamps as expiration dates.
9. Which system uses a trusted third party interface?
a) Public-Key Certificates
b) Public announcements
c) Publicly available directories
d) Public-Key authority
Answer: a
Clarification: Public-Key certificates use a trusted third party interface.
10. Publicly Available directory is more secure than which other system?
a) Public-Key Certificates
b) Public announcements
c) Public-Key authority
d) None of the mentioned
Answer: b
Clarification: Publicly Available directory is more secure than Public announcements.