Question

Difficulty: EasyCryptographic Concepts and Algorithms

A network administrator is configuring a secure transport session to protect financial telemetry transmitted across an untrusted enterprise network. The session configuration requires high-speed symmetric data confidentiality as well as a key exchange mechanism that guarantees Perfect Forward Secrecy (PFS). Which TWO of the following cryptographic mechanisms should the administrator select to meet these requirements?

  1. Elliptic Curve Diffie-Hellman Ephemeral (ECDHE)Answer
  2. Advanced Encryption Standard in Galois/Counter Mode (AES-GCM)Answer
  3. C
    Static Rivest-Shamir-Adleman (RSA) key transport
  4. D
    Standalone Secure Hash Algorithm 256-bit (SHA-256)
  5. E
    Certificate Signing Request (CSR) generation

Answer

Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) and Advanced Encryption Standard in Galois/Counter Mode (AES-GCM) must be selected.
To protect session data across an untrusted network with both high performance and forward secrecy, administrators pair a symmetric cipher for data payload confidentiality with an ephemeral key exchange protocol. Elliptic Curve Diffie-Hellman Ephemeral provides Perfect Forward Secrecy by establishing unique keying material for each session without relying on reusable private keys. Advanced Encryption Standard in Galois/Counter Mode provides authenticated symmetric bulk encryption, meeting both the performance and confidentiality objectives.

Step-by-Step Solution

1
Identify the key exchange requirement
Elliptic Curve Diffie-Hellman Ephemeral (ECDHE) provides key exchange with Perfect Forward Secrecy (PFS) using short-lived ephemeral key pairs.
PFS ensures that compromising a long-term private key does not compromise past session keys.
2
Identify the bulk confidentiality requirement
Advanced Encryption Standard in Galois/Counter Mode (AES-GCM) provides fast symmetric encryption along with authenticated integrity checks.
Symmetric ciphers are computationally efficient and designed for high-throughput bulk data protection.

Key Concept

Combining symmetric encryption for bulk confidentiality with ephemeral key exchange for forward secrecy.
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