9618Paper 1 · Theory Fundamentals§6.1, §6.2

6. Security, Privacy and Data Integrity

Data security vs data integrity, threats, prevention, validation and verification.

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Statometer57CoreNext Paper 171%

Marks a paper8.6 · 12%Rank#10 of 12 · #8 on P1Trend · last 12↗Full stats

Everything for this topic — study hub

AS Level · 9618 · Paper 1

Statometer — what 33 real papers say about this topic and each of its 2 syllabus bullets

Core · #10 of 12 in AS Level · recomputed with every new session

Core#10 of 12 in AS Level#8 on Paper 1↗ Rising

A regular, well-paid topic — you cannot afford a gap here.

Next Paper 1: 71%; 7 in 10 chance it is set
Marks a paper: 8.6 / 75; 12% of Paper 1 · fair share 13%
Appeared in: 25 / 33; Paper 1 sittings 2021–2026
Last set: May/Jun 2026; 9618/13 · Q1 · 5 marks · 11-series streak

Marks in each of the last 12 Paper 1 sittingsOct/Nov 24 → May/Jun 26

What the papers say

Set in 25 of 33 Paper 1 sittings — about 8 papers in 10.
Worth about 8.6 marks a paper (12% of Paper 1).
Last set May/Jun 2026 · 9618/13 · Q1 for 5 marks — in the most recent series.
Set in each of the last 11 series without a miss.
Rising: about 6.4 marks a paper in the earlier years, 9.3 in the latest.
Lives on “Describe” and “Explain” — 72% of its questions: full sentences with a reason, not one-word answers.
45% of its questions involve a diagram, table or figure — practise with pen and paper.
Its biggest question so far: 22 marks (May/Jun 2024 · 9618/13 · Q7).
Inside the topic, §6.1 Data security carries the most marks (60%) and §6.2 Data integrity the least (40%).
It is examined almost entirely as AO1 (Knowledge & understanding, 93%) — definitions and descriptions in syllabus words score.
The examiner has commented on 19 of its questions — read “What the examiner said” before you practise.

Command words

Share of questions using the word (a question can use several). What each wants →

Question shapes

≤ 6 mk10
7–9 mk7
10–12 mk4
13–15 mk5
16+ mk3

Average 9.1 marks a question · 45% with a figure or table · 24% with code · biggest 22 marks

Assessment objectives — how it is examined

Every part of every current-syllabus question filed under Cambridge's AO1 / AO2 / AO3 (from its command word and what it asks you to do), so you know whether this topic pays for definitions, for applying, or for judging and building.

AO1 93%

AO1 Knowledge & understanding
AO2 Apply & analyse
AO3 Design, program & evaluate

Paper 1 as a whole

Paper 1	Syllabus	Measured
AO1 Knowledge & understanding	60%	68%
AO2 Apply & analyse	40%	32%
AO3 Design, program & evaluate	0%	0%

Syllabus = Cambridge's grid; measured = the bank's current-syllabus papers.

Inside the topic — every syllabus bullet, measured

Each part of each question is filed under the bullet it examines; the numbers are per Paper 1 sitting, exactly like the topic's. Open a bullet for its own Statometer.

6.1Data security#13 of 25 on Paper 1Core · 5862% next paper3.2 marks21/33 sittings→ May/Jun 2026Core · 5862%
3.2 · 60% of topic21/33May/Jun 2026latest series · →
A regular earner inside the topic — most papers touch it.Syllabus: security, privacy and integrity; protecting systems (accounts, passwords, biometrics, firewalls, anti-virus, encryption); threats (malware, hackers, phishing, pharming)
Next Paper 1
62%
6 in 10
Marks a paper
3.2
4% of the paper · 60% of the topic
Asked in
21 / 33
Paper 1 sittings · 22 questions
Last asked
May/Jun 2026
9618/12 · Q2 · 6 marks · 11-series streak
Asked in 21 of 33 Paper 1 sittings — about 6 papers in 10.
About 3.2 marks a paper (4% of Paper 1; 60% of the topic's marks across its 2 bullets).
Last asked May/Jun 2026 · 9618/12 · Q2 (6 marks) — in the most recent series.
Asked in each of the last 11 series.
Usually “Describe” or “Explain”: full sentences with a reason, not one-word answers.
Biggest chunk of marks so far: 10 in May/Jun 2022 · 9618/12 · Q4.
It is examined almost entirely as AO1 (Knowledge & understanding, 97%) — definitions and descriptions in syllabus words score.
Last 12 sittings→ Steady
Assessment objectives
AO1 97%
AO1 Knowledge & understanding
AO2 Apply & analyse
AO3 Design, program & evaluate
Describe77%
Explain59%
Complete46%
Identify32%
Practise its 22 questions Biggest: 10 marks · May/Jun 2022
6.2Data integrity#14 of 25 on Paper 1Regular · 4751% next paper2.6 marks16/33 sittings↗ May/Jun 2026Regular · 4751%
2.6 · 40% of topic16/33May/Jun 2026latest series · ↗
Set most sessions for a few marks; know the definition and one example.Syllabus: validation (range, format, length, presence, existence, limit, check digit); verification on entry (visual, double entry) and on transfer (parity byte/block, checksum)
Next Paper 1
51%
5 in 10
Marks a paper
2.6
4% of the paper · 40% of the topic
Asked in
16 / 33
Paper 1 sittings · 19 questions
Last asked
May/Jun 2026
9618/13 · Q1 · 5 marks · 3-series streak
Asked in 16 of 33 Paper 1 sittings — roughly one paper in 2.
About 2.6 marks a paper (4% of Paper 1; 40% of the topic's marks across its 2 bullets).
Last asked May/Jun 2026 · 9618/13 · Q1 (5 marks) — in the most recent series.
Rising: 1.6 → 3.1 marks a paper.
Usually “Describe” or “Complete”: full sentences with a reason, not one-word answers.
Biggest chunk of marks so far: 7 in May/Jun 2026 · 9618/12 · Q2.
It is examined almost entirely as AO1 (Knowledge & understanding, 96%) — definitions and descriptions in syllabus words score.
Last 12 sittings↗ Rising
Assessment objectives
AO1 96%
AO1 Knowledge & understanding
AO2 Apply & analyse
AO3 Design, program & evaluate
Describe63%
Complete53%
Explain47%
State42%
Practise its 19 questions Biggest: 7 marks · May/Jun 2026

31% of the topic's marks sit in question parts that belong to another topic (scenario questions cross sections) or that no bullet claims; they count for the topic, not for a bullet.

Marks a paper, year by year

212223242526

By exam series

May/Jun14/18 · 7.8 mk
Oct/Nov11/15 · 8.3 mk

Practise 29 real questions Smart Notes Quiz Flashcards Every topic on the Statometer

What you need to know2syllabus §6.1, §6.2

6.1Data security — security, privacy and integrity; protecting systems (accounts, passwords, biometrics, firewalls, anti-virus, encryption); threats (malware, hackers, phishing, pharming)
6.2Data integrity — validation (range, format, length, presence, existence, limit, check digit); verification on entry (visual, double entry) and on transfer (parity byte/block, checksum)

Video lectures6ZAK's YouTube channel · play here

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Infographics3draw these the way the examiner expects · download as PNG

Error detection methods

O LevelAS

Cyber threats vs defences

O LevelAS

Security, privacy & integrity

Browse all infographics →

Key terms9use these exact words in the exam

data integritydata securitymalwarephishingpharmingvalidation verification checksum parity

Dotted terms are defined in the glossary.

Code help2referenced to the Cambridge pseudocode guide

Check-digit validation (modulus 11, ISBN-10 style)

pseudocode §5.5, §7.1 Run in Playground

DECLARE Code : STRING
DECLARE i, Sum, Check : INTEGER
Code ← "020161622"      // first 9 digits
Sum ← 0
FOR i ← 1 TO 9
   Sum ← Sum + STR_TO_NUM(MID(Code, i, 1)) * (11 - i)
NEXT i
Check ← (11 - (Sum MOD 11)) MOD 11
OUTPUT "Check digit: ", Check

Format check: ID must be 2 letters + 4 digits

pseudocode Run in Playground

FUNCTION IsLetter(C : CHAR) RETURNS BOOLEAN
   RETURN UCASE(C) >= 'A' AND UCASE(C) <= 'Z'
ENDFUNCTION
FUNCTION IsDigit(C : CHAR) RETURNS BOOLEAN
   RETURN C >= '0' AND C <= '9'
ENDFUNCTION
DECLARE ID : STRING
DECLARE OK : BOOLEAN
DECLARE i : INTEGER
ID ← "AB1234"
OK ← LENGTH(ID) = 6 AND IsLetter(MID(ID,1,1)) AND IsLetter(MID(ID,2,1))
FOR i ← 3 TO 6
   OK ← OK AND IsDigit(MID(ID, i, 1))
NEXT i
OUTPUT ID, " valid: ", OK

Playground examples7runnable programs for this topic

Caesar cipher — encrypt & decrypt
Shift letters with ASC and CHR, wrapping with MOD 26. Same key both ways = symmetric encryption.
O LevelASA2PseudocodeString handling §5.5 · 2210 §5 / 9618 §6.2 security
Run
Range check
Keep asking until the value is between 0 and 100.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Presence & length checks
Nothing entered? Too short or too long? Say which check failed.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Type check — digits only
A function that tests every character before the string is converted to a number.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Format check — is this an email address?
One @ that is not first, and a dot after it that is not last.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run
Check digit — ISBN-13
Weights 1 and 3 alternate, total MOD 10, subtract from 10. The classic check-digit algorithm.
O LevelASPseudocodeValidation, testing & exceptions 2210 §2.3, §7.3
Run
Verification — double entry
Validation checks the data is sensible; verification checks it was entered correctly.
O LevelASPseudocodeValidation, testing & exceptions 2210 §7.3 / 9618 §6.2
Run

Test yourself

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Quiz: Security, Privacy & Data Integrity (36)🃏 Flashcards: mix this topic (41)⚖️ Data security & privacy (23)✅ Data integrity — validation & verification (18)Past-paper questions (29)🧪 Validation & check digits 🔐 Encryption lab

Everything for this topic — study hub

Statometer — what 33 real papers say about this topic and each of its 2 syllabus bullets

What you need to know2syllabus §6.1, §6.2

Video lectures6ZAK's YouTube channel · play here

Prog. Basics 2 · Good Programming Practices · Validation Veri · Lib. Routines · O/AS Level

Verification & Validation · O & AS Levels

Data Integrity · AS Level

Data Security · AS Level · URDU

2.1.1 Problem-solving and design (part 2, validation and verification checks)

1.3.7 High- and low-level languages and their translators (Complete) 1.4 Security (part 1)

Infographics3draw these the way the examiner expects · download as PNG

Key terms9use these exact words in the exam

Code help2referenced to the Cambridge pseudocode guide

Playground examples7runnable programs for this topic

Ready to check you know it?