Question

Difficulty: MediumCryptographic Concepts and Algorithms

Match each cryptographic primitive or mechanism to its primary operational security function in an enterprise environment.

  • Ephemeral Diffie-Hellman (ECDHE)Provides perfect forward secrecy to ensure past session traffic remains secure if long-term server private keys are later compromised.
  • Hash-based Message Authentication Code (HMAC)Combines a symmetric secret key with a cryptographic hash function to verify data integrity and message authenticity.
  • Cryptographic Salt with PBKDF2Defends stored credential hashes against precomputed dictionary and rainbow table attacks.
  • Cipher Block Chaining (CBC) ModeEnsures sequential data confidentiality by XORing each plaintext block with the preceding ciphertext block before encryption.

Answer

Ephemeral Diffie-Hellman matches providing perfect forward secrecy; HMAC matches message integrity and authenticating origin; Cryptographic Salt with PBKDF2 matches protecting password stores against rainbow tables; Cipher Block Chaining Mode matches block-level sequential data confidentiality.
Ephemeral Diffie-Hellman provides key exchange with forward secrecy; HMAC ensures keyed message integrity and authentication; Salting prevents precomputed hash lookup attacks on credentials; CBC mode encrypts data blocks in sequence using feedback from previous blocks.

Step-by-Step Solution

1
Analyze Ephemeral Diffie-Hellman (ECDHE)
Identified requirement for session key isolation and forward secrecy.
Ephemeral key exchanges produce unique keys per session that do not depend on long-term private keys.
2
Analyze Hash-based Message Authentication Code (HMAC)
Identified requirement for message integrity combined with authentication using a shared secret.
Standard hashing only provides integrity; HMAC adds a secret key to provide origin verification.
3
Analyze Cryptographic Salt with PBKDF2
Identified requirement for password hashing defense against precomputed tables.
Salting adds random data per user password to defeat rainbow table lookups.
4
Analyze Cipher Block Chaining (CBC) Mode
Identified requirement for block cipher confidentiality via chaining.
CBC mode uses XOR operations with preceding blocks to randomize ciphertexts of repeating plaintext.

Key Concept

Cryptographic Primitives and Operational Security Functions
Rate this question