SSCA Cryptography & PKI

Question 1

Which cryptographic algorithm uses the same key for both encryption and decryption?

Accepted Answer

AES

Answer

RSA

Answer

Elliptic Curve Cryptography

Answer

Diffie-Hellman

Question 2

What is the primary role of a Certificate Authority (CA) in a PKI infrastructure?

Accepted Answer

Issuing and digitally signing digital certificates to validate identities

Answer

Encrypting data in transit between clients and servers

Answer

Storing private keys on behalf of users

Answer

Performing key exchange using Diffie-Hellman

Question 3

Which property of a cryptographic hash function ensures that two different inputs cannot produce the same hash output?

Accepted Answer

Collision resistance

Answer

Pre-image resistance

Answer

Key stretching

Answer

Avalanche effect

Question 4

In asymmetric cryptography, which key is used to verify a digital signature?

Accepted Answer

The signer's public key

Answer

The signer's private key

Answer

A shared symmetric key

Answer

A session key derived from Diffie-Hellman

Question 5

What does the X.509 standard define?

Accepted Answer

The format and fields of digital certificates used in PKI

Answer

A protocol for secure key exchange over untrusted networks

Answer

An encryption algorithm for protecting data at rest

Answer

A method for generating pseudo-random numbers

Question 6

Which mechanism allows a relying party to check in real time whether a digital certificate has been revoked?

Accepted Answer

Online Certificate Status Protocol (OCSP)

Answer

Certificate Revocation List (CRL)

Answer

Certificate Signing Request (CSR)

Answer

Key Escrow

Question 7

What is the purpose of key stretching techniques such as PBKDF2 or bcrypt?

Accepted Answer

To slow down brute-force and dictionary attacks against passwords

Answer

To extend the length of an encryption key beyond its native size

Answer

To distribute encryption keys securely across a network

Answer

To convert asymmetric keys into symmetric keys for performance