TO CRYPTOGRAPHY 200
QUESTIONS AND
ANSWERS|2025 UPDATE
100% CORRECT
[Document subtitle]
[DATE]
[COMPANY NAME]
[Company address]
,1. Q: A business wants to use keys issued by a trusted third party to demonstrate to
potential customers that it is a legitimate organization. Which key is used to sign
the certificate issued to the business?
A: C. Private key of the root CA
2. Q: A business wants to use keys issued by a trusted third party to demonstrate it
is a legitimate organization to potential customers. Which key should the
business send to potential customers to prove its identity?
A: D. Public key of the company
3. Q: What should an administrator use to import and export all items written using
X.509 that are part of a chain of trust?
A: C. Public Key Cryptography Standard (PKCS) #12
4. Q: Which field displays the hash, or digest, of the certificate in an X.509
certificate?
A: D. Thumbprint
5. Q: Which certificate management process involves key recovery?
A: B. Issued
6. Q: Which task does a root CA perform before publishing its own certificate?
A: C. Signing it with its private key
7. Q: Which algorithm is used to generate the thumbprint of a certificate?
A: D. SHA-1
8. Q: Large volumes of plaintext need to be encrypted, and the encryption keys
need to be securely distributed. Which approach should be used for encryption
and distribution?
A: A. Encrypt by using symmetric keys and distribute by using asymmetric keys
9. Q: What is the role of a key in asymmetric encryption and decryption?
A: C. A public key is used for encryption, and a private key is used for decryption.
10. Q: A security analyst is validating the integrity and authenticity of a data
transaction. Which PKI component is being used?
A: B. Digital signature
11. Q: Which PKI component generates digital certificates?
A: D. Certificate authority (CA)
12. Q: What is the maximum length (in bits) of encryption keys used by the WEP
protocol?
A: B. 56
, 13. Q: What is a difference between WPA-Enterprise and WPA-Personal?
A: B. Support for an authentication server
14. Q: Which cipher is used with WEP?
A: B. RC4
15. Q: How does TKIP improve WPA over WEP?
A: A. Hashes the initialization vector and secret key
16. Q: An administrator has configured a virtual private network (VPN) connection
utilizing IPsec tunnel mode with Encapsulating Security Payload (ESP) between
the corporate office and a remote office. Where can the packets be inspected by
intrusion detection systems (IDSs) and virus scanners?
A: C. At the headquarters and the offsite location
17. Q: Which default port must be open for the IPsec key exchange to be successful?
A: D. UDP 500
18. Q: Which protocol indicates the virtual private network (VPN) is using
Authentication Header (AH)?
A: C. 51
19. Q: Which cipher uses a grid to map letters into numeric values?
A: A. Bifid
20. Q: Which cipher uses a five-by-five matrix with nonrepeating characters?
A: A. Playfair
21. Q: What does a frequency analysis attack to break encryption involve?
A: A. Analyzing ciphertext to identify text variation and comparing the text to
standard English characters
22. Q: Which technique should a security analyst use to determine the key length in
a Vigenère cipher?
A: C. Kasiski examination
23. Q: What defines a prime number?
A: A. Only has factors of itself and 1
24. Q: What is 29 mod 12?
A: C. 5
25. Q: Which type of cipher is ChaCha?
A: C. Stream
26. Q: What is the key size for RC4 with WEP?
A: A. 40 bits