AS Level Computer Science chapter 6: Security, privacy and data integrity MCQs with answers
By Team Megalecture · Updated 4 Nov 2026
23 exam-style questions on Security, privacy and data integrity, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.
Ten Security, privacy and data integrity questions with answers
Try each one, then open the answer. These ten stay the same; the test draws new ones every time.
1. Why can a single parity bit per byte not detect every transmission error?
A
if two bits flip, the byte still has the correct parity
B
the parity bit itself is sometimes lost during transfer
C
parity only works when an odd number of bytes is sent
D
parity checks the order of bytes, not their values
Show answer
Answer: A. Changing two bits keeps the count of 1s odd or even as before, so the error goes unnoticed. A parity block check or checksum gives better protection.
2. What does a firewall do?
A
blocks traffic that breaks a set of rules
B
scans each stored file for known virus signatures
C
converts all outgoing data into ciphertext
D
checks each user's fingerprint before they log on
Show answer
Answer: A. A firewall sits between a network and the outside, filtering incoming and outgoing traffic against rules such as allowed IP addresses and ports. Scanning files is anti-virus software.
3. A new password is typed twice when an account is created and the two entries are compared. What is this method?
A
double entry
B
a presence check
C
a visual check
D
a checksum
Show answer
Answer: A. Typing data twice and comparing the copies is double entry, a verification method used during data entry.
4. Why is biometric authentication often considered stronger than a password?
A
the biometric data never needs to be stored anywhere
B
a physical feature is unique and hard to share or guess
C
biometric systems never reject a genuine, valid user
D
biometrics also encrypt all the data on the disk
Show answer
Answer: B. A fingerprint or face cannot be written down, forgotten or guessed. Biometric templates must still be stored, and systems can reject genuine users.
5. A laptop containing encrypted files is stolen. Why is the data still protected?
A
without the decryption key the files cannot be understood
B
encryption stops the files from being copied to another disk
C
encrypted files delete themselves when the laptop is stolen
D
encryption stops the laptop from starting up for the thief
Show answer
Answer: A. Encryption does not stop data being copied or stolen; it makes the data meaningless to anyone who does not have the key.
6. What is the difference between validation and verification?
A
validation: data is sensible; verification: it matches its source
B
validation checks data is correct; verification checks it is sensible
C
both check that the data is accurate, but using different software
D
validation is done by people, but verification is done by computer
Show answer
Answer: A. Validation is an automatic check that data is sensible and obeys rules. Verification checks the data was copied or transmitted accurately from its source.
7. A customer ID typed into an order form is checked to make sure it is in the customer table. Which validation check is this?
A
presence check
B
existence check
C
format check
D
limit check
Show answer
Answer: B. An existence check confirms that a value, such as a key or file name, actually exists. A presence check only tests that something was entered.
8. An exam mark must be a whole number from 0 to 100 inclusive. Which validation check tests this?
A
length check
B
format check
C
range check
D
presence check
Show answer
Answer: C. A range check tests that a value lies between a lower and an upper limit. A limit check tests only one boundary.
9. A user gets an email that looks as if it is from their bank, asking them to click a link and confirm their login details. What threat is this?
A
pharming
B
phishing
C
spyware
D
a virus
Show answer
Answer: B. Phishing uses legitimate-looking messages to trick users into giving personal data. In pharming the user is redirected without clicking a suspicious link.
10. Even parity is used. Which received byte contains an error?
A
10110100
B
00000000
C
01100011
D
11010011
Show answer
Answer: D. With even parity every byte must contain an even number of 1s. 11010011 has five 1s; the others have four, zero and four.
Security, privacy and data integrity: questions students ask
How many Security, privacy and data integrity MCQs are there?
23, each with the answer and a short explanation, across 2 topics: Data security, Data integrity. Every chapter test draws ten of them, so you can take it many times.
Is the AS Level Computer Science chapter 6 test free?
Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.
How is the chapter test marked?
The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.
