Notes
Passwords and encryption
- Strong passwords are long, unique and not personal. Brute force tries every combination; dictionary attacks try common passwords. Two-factor authentication adds a second proof.
- Encryption turns plaintext into ciphertext with a key. The Caesar cipher shifts letters (shift 3: A becomes D). Symmetric encryption uses one key; public-key encryption uses a public key to encrypt and a private key to decrypt. HTTPS uses encryption.
Threats and privacy
- Phishing is a fake message designed to steal information; look for urgency, odd senders and mismatched links. Malware includes viruses, ransomware and spyware.
- PII is information that identifies a person. Your digital footprint is the data trail you leave. Check app permissions and privacy settings.
Impacts
- Bias in AI comes from biased training data. AI can be wrong, so check important results. The digital divide is unequal access to technology.
- Respect copyright and licenses such as Creative Commons. Good digital citizenship means being respectful, honest and responsible online.
Topics in this unit
Each topic has its own short notes and practice.
Practice
A second factor stops attackers who only have the password.
A becomes B and B becomes C.
Public-key systems use a key pair: one public and one private.
The odd address, urgency and link are classic phishing signs.
Unrepresentative training data causes bias and unequal accuracy.
Respecting others' privacy and consent is part of being a responsible digital citizen.
Free response
Write your answer first, then open the scoring guide.
Free-response question
Maya is setting up an account for a school photo-sharing app.
(a) Give two features of a strong password that Maya should use.
Show the answer and scoring guide
It should be long (12 or more characters) and unique to this account. It should avoid personal information such as her name or birthday.
Check off the points you earned:
(b) Maya gets a message saying "Your app account will be deleted today unless you enter your password at this link." Identify two warning signs of phishing and say what she should do.
Show the answer and scoring guide
Warning signs are the urgent deadline and the request for her password through a link. She should not click it, and should go to the official app or site herself or report the message.
Check off the points you earned:
(c) The app asks for her location and contacts. Explain one privacy concern and one way to protect her privacy.
Show the answer and scoring guide
Her location and contacts are personal information that could be shared or leaked and used to track or contact her. She can deny unneeded permissions or limit who sees her posts with privacy settings.
Check off the points you earned: