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🏆 Score: 0 / 20
1 [3 Marks Total]
(a) Which statement best describes the purpose of encryption? Tick one. [1]
To prevent hackers from intercepting data packets sent over a network.
To scramble data so that it cannot be understood if it is intercepted.
To compress data so that it transmits faster over the network.
To permanently delete data so it cannot be recovered.
(b) State the technical name for data BEFORE encryption. [1]
(c) State the technical name for data AFTER encryption. [1]
✅ Mark Scheme

(a) To scramble data so that it cannot be understood if it is intercepted.

⚠️ Common Mistake Encryption does NOT prevent interception (stealing). The hacker can still take the file, they just can't read it!

(b) Plaintext (1)

(c) Ciphertext (1)

Score yourself (Max 3):
2 [5 Marks Total]
Scenario: Student logging into bank website on coffee shop Wi-Fi.
(a) How can the student verify the browser connection is encrypted? [1] (b) Explain why encryption is important for the bank. [2] (c) A hacker steals the data packets. Can they access the bank account? Explain. [2]
✅ Mark Scheme

(a) Look for Padlock icon OR 'https://' in URL (1).

(b) Importance: Data contains sensitive financial info (1). If unencrypted, hacker could steal money/identity (1).

(c) Can they access? No (1). Because data is scrambled/meaningless without the key (1).

Score yourself (Max 5):
3 [4 Marks Total]
Encryption Keys.
(a) Describe the role of the Key. [2] (b) Why does a longer key (e.g. 256-bit) make encryption more secure? [2]
✅ Mark Scheme

(a) Role: Used by algorithm to turn plaintext into ciphertext (1) AND to turn ciphertext back to plaintext (1).

(b) Length: More possible combinations (1), so takes much longer to brute-force/guess (1).

Score yourself (Max 4):
4 [8 Marks Total]
Company sending confidential email.
(a) Manager says: "Encryption stops data from being stolen." Explain why this is incorrect. [2] (b) Describe steps to send encrypted message. Use: Plaintext, Algorithm, Ciphertext, Key. [4]
✅ Mark Scheme

(a) Incorrect because: Encryption does not stop physical interception (1). It only ensures the stolen data is unreadable (1).

(b) Process Steps:

  1. Start with Plaintext message.
  2. Apply encryption Algorithm.
  3. Using a Key to convert to Ciphertext.
  4. Recipient uses Key to decrypt back to Plaintext.
Score yourself (Max 8):