SSCP Certification SSCP Cryptography Fundamentals 2 — Questions and Answers
Question 1: Which cryptographic attack involves an attacker intercepting and possibly altering communications between two parties without their knowledge?
- Replay attack
- Man-in-the-middle attack (Correct answer)
- Birthday attack
- Chosen-plaintext attack
Correct answer: Man-in-the-middle attack
A man-in-the-middle (MITM) attack occurs when an attacker secretly intercepts and potentially modifies communications between two parties who believe they are communicating directly.
Question 2: What is the primary purpose of a Message Authentication Code (MAC)?
- Encrypting the message content
- Verifying both data integrity and authenticity (Correct answer)
- Compressing data before transmission
- Generating public/private key pairs
Correct answer: Verifying both data integrity and authenticity
A MAC provides data integrity and authenticity verification by using a shared secret key to produce a tag that confirms the message has not been altered and came from a legitimate sender.
Question 3: Which of the following best describes perfect forward secrecy (PFS)?
- Using the same session key for all communications
- Ensuring that compromise of long-term keys does not compromise past session keys (Correct answer)
- Encrypting data with multiple layers of encryption
- Using one-time pads for every session
Correct answer: Ensuring that compromise of long-term keys does not compromise past session keys
Perfect forward secrecy ensures that session keys are not compromised even if the server's long-term private key is later exposed, by using ephemeral key exchange methods like ECDHE.
Question 4: In asymmetric encryption, which key is used to encrypt data that only the recipient should read?
- Recipient's private key
- Sender's private key
- Recipient's public key (Correct answer)
- Sender's public key
Correct answer: Recipient's public key
Data intended for a specific recipient is encrypted with the recipient's public key; only the recipient's corresponding private key can decrypt it.
Question 5: What distinguishes a stream cipher from a block cipher?
- Stream ciphers use asymmetric keys; block ciphers use symmetric keys
- Stream ciphers encrypt one bit or byte at a time; block ciphers encrypt fixed-size chunks (Correct answer)
- Stream ciphers require padding; block ciphers do not
- Stream ciphers are slower than block ciphers in all scenarios
Correct answer: Stream ciphers encrypt one bit or byte at a time; block ciphers encrypt fixed-size chunks
Stream ciphers encrypt data bit-by-bit or byte-by-byte continuously, while block ciphers operate on fixed-size groups of bits, typically 64 or 128 bits.
Question 6: Which hashing algorithm produces a 256-bit digest and is commonly used in TLS and certificate signing?
- MD5
- SHA-1
- SHA-256 (Correct answer)
- RIPEMD-128
Correct answer: SHA-256
SHA-256 is part of the SHA-2 family, produces a 256-bit hash digest, and is widely used in TLS, digital certificates, and blockchain applications.
Question 7: What is a rainbow table attack?
- Brute-forcing every possible password sequentially
- Using precomputed hash values to reverse password hashes (Correct answer)
- Injecting malicious code into cryptographic libraries
- Intercepting encrypted traffic and decrypting it offline
Correct answer: Using precomputed hash values to reverse password hashes
A rainbow table attack uses precomputed tables of hash values to quickly reverse-lookup plaintext passwords from their hashes, defeating unsalted password storage.
SSCP Certification SSCP Cryptography Fundamentals 2
Which cryptographic attack involves an attacker intercepting and possibly altering communications between two parties without their knowledge?