YanoSecA club stores a private budget, a meeting time, and a sign-in page. Protecting them means asking three different questions: who can read the budget, who can change the time, and whether members can reach the page. These are the security goals called confidentiality, integrity, and availability, often shortened to CIA.
Confidentiality preserves authorized limits on reading or disclosure. Integrity protects information against improper change or destruction. Availability means authorized users can obtain and use information when needed. A control is a measure chosen to reduce a particular harm. Naming the harm helps you choose a control that fits.
Before you begin
- Recommended first
- How a web app is put together, Same-origin policy, Binary, hex, Base64, and URL encoding
- Estimated time
- 14 min reading, 10 min activity. Setup and optional practice may take longer.
- Where you work
- Read the fictional cards in any current desktop or mobile browser. No installation, account, password tool, directory deployment or network request is required. Use only the evidence supplied on this page.
- Without a lab
- The page prints the evidence needed for the activity. Write your classifications and reasons in notes, then compare them with the activity rubric. This practices reasoning; it does not reproduce a live incident or tool operation. Reading works without JavaScript. Answer checking requires JavaScript and a secure browser context; saving progress also requires usable browser storage.
After this lesson you can:
- Name the direct harm in a short incident as confidentiality, integrity, or availability.
- Choose a control that addresses that harm and state one thing the control does not do.
- Say when one incident can touch a second goal without changing the direct harm.
01Example
Read these fictional incidents as a demonstration of the three goals. Each line supplies the event and its direct harm. No system was changed.
Card P: a passerby reads the draft budget. Direct harm: confidentiality.
Card Q: the meeting time changes from Tuesday to Friday with an empty edit log. Direct harm: integrity.
Card R: the sign-in page does not load. Direct harm: availability.
A spare copy helps card R. It does not decide who may read the budget.02Three goals, one direct harm
Begin with the event. An unintended reader points to confidentiality. An unauthorized change points to integrity. A service that cannot be used points to availability. The asset is the information or service being protected; the event explains what happened to it.
An incident can affect several goals. Deleting the only schedule both destroys information and prevents members from using it. When a case emphasizes the inability to open it, name availability as the direct harm and record the destruction as another concern. A backup helps recovery, but its contents still need access restrictions.
Match a harm to confidentiality, integrity, or availability, then name a control that fits that harm.Model. A teaching model drawn by hand. It shows the idea, not real tool output.
Read the full explanation below.
Name the direct harm first.
met · A passerby reads the draft budget.A spare copy helps card R. It does not decide who may read the budget.
met · Lock the screen before leaving.An unintended reader is the direct harm; locking now cannot hide a copy already made.
Match controls to the stated harm; one control does not satisfy every CIA goal.
An unintended reader is the direct harm; locking now cannot hide a copy already made.
Follow the explanation
- An unintended reader is the direct harm; locking now cannot hide a copy already made.
- The improper change is the direct harm; a log does not repair earlier wrong data.
- Recovery helps the outage; the spare copy supplies no reading restriction.
Read every state and value
1. An unintended reader is the direct harm; locking now cannot hide a copy already made.
- Case
- p
- Conditions inspected
- Direct harm · Fitting control
- Decision shown
- Yes
2. The improper change is the direct harm; a log does not repair earlier wrong data.
- Case
- q
- Conditions inspected
- Direct harm · Fitting control
- Decision shown
- Yes
3. Recovery helps the outage; the spare copy supplies no reading restriction.
- Case
- r
- Conditions inspected
- Direct harm · Fitting control
- Decision shown
- Yes
03Classify three activity cards
Cards K, L, and M are a new set. Cover the check line, write a goal for each card, then look.
Original fictional incident cards. Not observed events. No system was changed.
Worked cards
Card P
Asset: draft club budget
Event: a passerby reads the budget on an unattended signed-in screen
Direct harm: confidentiality
Control on this card: lock the screen before leaving
Limit: locking now does not hide a copy that was already made
Card Q
Asset: meeting time
Event: the time changes from Tuesday to Friday and the edit log is empty
Direct harm: integrity
Control on this card: allow changes only from named editors, and keep the edit log
Limit: an edit log does not repair a time that was already wrong when the log started
Card R
Asset: sign-in page
Event: the page does not load for anyone who is allowed to use it
Direct harm: availability
Control on this card: keep a tested spare way to reach the page
Limit: a spare copy does not decide who may read the budget
One event can touch more than one goal. Name the direct harm first.
Activity cards. The goals are not filled in.
Card K
Asset: the only copy of the practice schedule
Event: the file is deleted, and members who are allowed to read it cannot open it
Control that matches this event: a tested spare copy
What that control does not do: it does not stop a passerby from reading a different file
Card L
Asset: a private comment
Event: every signed-in member can read the comment
Control that matches this event: restrict reading to the people named on the comment
Card M
Asset: a practice score
Event: the score changes from 3 to 9 and the edit log is empty
Control that matches this event: accept changes only from named editors
Check: card K is availability. Card L is confidentiality.
Card M is the same kind of change as worked card Q.
- For each activity card, write the asset and the event in your own words.
- Name the direct harm. Then name the control printed on that card and one limit of that control.
- Check: card K is availability. Card L is confidentiality. Card M is the same kind of change as worked card Q.
- Stop. These cards are fiction. Do not delete a file or change a score to test them.
04Optional challenge
Allow about ten minutes. Suppose the spare copy for activity card K is publicly readable. Explain the new harm as well as the recovery benefit. Your note should connect one control to one goal and state why the other goal still needs its own control.
05Fresh cases for the checks
Use these fictional cases for the checks below. They have different inputs from the worked examples. Read them here or make notes; no installation or external service is needed.
CIA case A: independent incident recordsOwned fixture. An original file made for this course. Follow the activity's instructions in your own lab.
J: a private mentor roster is copied by an unauthorized reader; the original remains correct and usable.
K: an unauthorized edit changes a room booking from Room 2 to Room 9; the service stays reachable.
L: an outage prevents authorized members from opening the timetable; no disclosure or changed entry is supplied.
CIA case B: recovery with a separate exposureOwned fixture. An original file made for this course. Follow the activity's instructions in your own lab.
A club restores lost rota entries from a working spare copy. That copy was also placed at a public URL without reading restrictions. A separate rule limits editing of the original to coordinators.
06Explain your prediction
Optional written self-check: For one incident, name asset, direct harm, fitting control and a residual concern. Explain multiple effects without claiming that a control for one goal automatically covers all three.
07Common mistakes
If you marked card K as confidentiality, you described a different event, such as a passerby reading the file. Card K says the allowed readers cannot open the only copy.
If you marked card L as availability, you described an outage. Card L says the comment is readable by every signed-in member.
If you treated the spare copy as a reading limit, you gave a recovery control the job of confidentiality.
References
- NIST CSRC glossary: confidentiality
The first definition is preserving authorized restrictions on information access and disclosure, including privacy and proprietary information. The page attributes it to FIPS 200.
- NIST CSRC glossary: integrity
The first definition is guarding against improper information modification or destruction, and includes nonrepudiation and authenticity. The page attributes it to FIPS 200.
- NIST CSRC glossary: availability
The first definition is ensuring timely and reliable access to and use of information. The page attributes it to FIPS 200.