🛡️ Free practice test question from: Electronic Codebook (Security+)

Imagine encryption like a complex lock where you transform your original message (plaintext) into an unreadable format (ciphertext) that can only be unlocked with a specific key. Block encryption algorithms like AES divide data into fixed-size blocks before encrypting them. In Electronic Codebook (ECB) mode, each block of plaintext is encrypted independently using the same key. This sounds simple, but it creates a significant security vulnerability.

The fundamental problem with ECB mode is that identical plaintext blocks will always produce identical ciphertext blocks. This means patterns in the original data can be preserved even after encryption.

Example:
→ Imagine you're sending secret messages about bank transactions

→ In ECB mode, if two transactions have exactly the same details (like the same amount to the same account), those blocks will look identical in the encrypted data

→ An attacker can potentially recognize these repeated patterns without even knowing the encryption key

For more: https://www.hackerone.com/vulnerability-management/cryptographic-failures

A) Collision attacks are more relevant to hashing algorithms rather than encryption modes like ECB.

B) While ECB does not use an Initialization Vector (IV), the primary issue highlighted in the scenario is the visibility of patterns, not replay attacks.

D) ECB mode is a symmetric encryption method and does not involve public and private keys; that pertains to asymmetric encryption.