ITPEC FE Morning April 2021 Question 38

Source exam: ITPEC FE Morning April 2021Topic: Security

ITPEC FE Morning April 2021 — Question 38 of 80

Symmetric Encryption (AES) — AES uses the same key for both encryption and decryption.

Why AES:
- AES is a symmetric cipher — one shared key encrypts and decrypts

- Fast and suitable for encrypting data at rest (e.g., databases)

Why not others:
- (b) PKI — not an encryption algorithm; it's an infrastructure for managing digital certificates and keys

- (c) RSAasymmetric encryption (uses a public/private key pair)

- (d) SHA-256 — a hash function, not encryption; hashing is one-way and cannot be reversed

Key rule: "Same key" = symmetric → AES, DES, 3DES. "Two keys" = asymmetric → RSA, ECC.

AI-generated — may contain errors

The original exam layout is preserved in the image so diagrams, formulas, tables, and code remain accurate.

This question comes from an official ITPEC past paper. ITPEC Practice is an independent study tool and is not affiliated with ITPEC. See the official FE past-paper collection or Report an issue.