Attacks and brute force

How attackers get in

• Beyond malware, attackers use direct attacks. The exam lists several:
• Brute-force attack — trying every possible password until one works.
• Hacking — gaining access without permission, often through a weakness.

Attacks on the network

• Data interception — "listening in" on data as it travels, to steal it (a packet sniffer).
• Denial of Service (DoS) — flooding a server with so many requests that it cannot serve real users.
• A DDoS does this from thousands of machines at once, so it is hard to block.

Why short passwords fail

• A 4-digit PIN has only 10,000 combinations. A computer tries millions per second.
• Below, brute-force a PIN by trying every value — then notice how a longer password would have far more combinations.

The lesson

• Each extra character multiplies the number of guesses needed.
• That is why length is the single most powerful thing about a password — more on that soon.

Covers: IGCSE 5.3 (brute-force, hacking, interception, DDoS).