SSCP Certification SSCP Cryptography Fundamentals 4 — Questions and Answers
Question 1: What is key stretching, and why is it used in password-based cryptography?
- Extending key length by appending zeros to meet algorithm requirements
- Applying a function repeatedly to make brute-force attacks slower and costlier (Correct answer)
- Distributing a key across multiple servers for redundancy
- Converting symmetric keys into asymmetric key pairs
Correct answer: Applying a function repeatedly to make brute-force attacks slower and costlier
Key stretching algorithms like PBKDF2, bcrypt, and Argon2 apply a hash function thousands of times to a password, making brute-force and dictionary attacks computationally expensive.
Question 2: Which digital signature algorithm is based on elliptic curve cryptography and is used in modern TLS certificates?
- RSA-PSS
- DSA (Digital Signature Algorithm)
- ECDSA (Elliptic Curve Digital Signature Algorithm) (Correct answer)
- ElGamal
Correct answer: ECDSA (Elliptic Curve Digital Signature Algorithm)
ECDSA uses elliptic curve mathematics to produce digital signatures, offering equivalent security to RSA with much smaller key sizes, making it popular in TLS, SSH, and cryptocurrency.
Question 3: In a hybrid encryption scheme, how is asymmetric encryption typically used?
- To encrypt the entire message content
- To encrypt only the symmetric session key used for bulk data encryption (Correct answer)
- To generate hash values for message authentication
- To compress data before symmetric encryption
Correct answer: To encrypt only the symmetric session key used for bulk data encryption
Hybrid encryption uses asymmetric cryptography to securely exchange a symmetric session key, and the much faster symmetric cipher encrypts the actual data — combining security with performance.
Question 4: What is the purpose of an initialization vector (IV) in symmetric encryption?
- To increase the key length of the cipher
- To ensure identical plaintexts produce different ciphertexts when encrypted with the same key (Correct answer)
- To authenticate the sender of encrypted data
- To compress plaintext before encryption
Correct answer: To ensure identical plaintexts produce different ciphertexts when encrypted with the same key
An IV is a random value used along with the encryption key to ensure that encrypting the same plaintext twice with the same key produces different ciphertext, preventing pattern analysis.
Question 5: Which attack exploits the birthday paradox to find hash collisions more efficiently than brute force?
- Preimage attack
- Length extension attack
- Birthday attack (Correct answer)
- Side-channel attack
Correct answer: Birthday attack
A birthday attack exploits the birthday paradox probability to find two inputs with the same hash in approximately 2^(n/2) operations rather than 2^n, significantly reducing collision resistance.
Question 6: What does 'cryptographic agility' mean in system design?
- The ability to encrypt data faster under high load
- The capability to switch between cryptographic algorithms without major system changes (Correct answer)
- Using multiple keys simultaneously for redundancy
- Automatically rotating encryption keys on a schedule
Correct answer: The capability to switch between cryptographic algorithms without major system changes
Cryptographic agility refers to designing systems so that cryptographic algorithms can be swapped out easily, allowing migration when algorithms become deprecated or broken without redesigning the entire system.
Question 7: Which SSCP-relevant concept describes the practice of splitting a cryptographic key among multiple custodians so no single person has full access?
- Key escrow
- Split knowledge (M-of-N control) (Correct answer)
- Key encapsulation
- Public key pinning
Correct answer: Split knowledge (M-of-N control)
Split knowledge (also called M-of-N control or secret sharing) divides a cryptographic key among multiple custodians, requiring a minimum number (M) of them to cooperate to reconstruct the full key.
SSCP Certification SSCP Cryptography Fundamentals 4
What is key stretching, and why is it used in password-based cryptography?