ITPEC FE Morning April 2020 Question 36

Brute force — the attacker tries every possible value, or a great many of them, until one works.

A brute force attack submits password or PIN candidates one after another. A four-digit PIN has only 10⁴ = 10,000 values, so it falls quickly unless the system locks the account after a few failures.

Answer (a)

Why not others:

• •(b) Denial of service — floods a system with traffic or requests to make it unavailable; it steals nothing
• •(c) Man-in-the-middle — sits between two parties, intercepting and possibly altering their messages, rather than guessing
• •(d) Sniffing — passively captures traffic on a network and reads what passes; no guessing is involved

Key rule: Defend against trial and error by limiting it: account lockout after failed attempts, and long passwords that make the search space too large.

Security · AI-written, may contain errors