SE Cryptography and PKI 3

Question 1

In a PKI hierarchy, what is the role of an Intermediate CA?

Accepted Answer

It issues end-entity certificates, insulating the Root CA from direct exposure

Answer

It stores private keys for end users

Answer

It revokes the Root CA certificate

Answer

It generates password hashes

Question 2

What is the purpose of salting a password before hashing?

Accepted Answer

Prevent precomputed (rainbow table) attacks by making each hash unique

Answer

Speed up the hashing process

Answer

Allow password recovery

Answer

Encrypt the password

Question 3

Which cipher mode of operation provides both confidentiality and integrity in a single pass?

Accepted Answer

GCM (Galois/Counter Mode)

Answer

ECB

Answer

CBC

Answer

CTR

Question 4

What does certificate pinning accomplish in a mobile application?

Accepted Answer

Restricts the app to accept only specific certificates, preventing MITM via rogue CAs

Answer

Speeds up TLS handshakes

Answer

Pins the UI layout to the screen

Answer

Stores the certificate on the device permanently

Question 5

An attacker collects two different messages that produce the same hash value. What type of cryptographic attack is this?

Accepted Answer

Birthday (collision) attack

Answer

Pre-image attack

Answer

Length extension attack

Answer

Side-channel attack

Question 6

Which key management practice ensures that encryption keys are changed regularly to limit exposure from a compromise?

Accepted Answer

Key rotation

Answer

Key wrapping

Answer

Key derivation

Answer

Key splitting