Israel Bagrut Computer Science 5 Units cheat sheet

Ethics, Social Implications, and Information Security

• CIA triad: confidentiality (only authorized access), integrity (data not altered improperly), availability (accessible when needed).

• Symmetric encryption (AES) uses one shared key and is fast; asymmetric (RSA) uses a public/private pair and solves key distribution but is slow.

• Hashing (SHA-256) is one-way and collision-resistant; it stores passwords with a per-user salt to defeat rainbow tables.

• Digital signature = hash of the message encrypted with the sender's private key; it proves integrity and authenticity but not confidentiality.

• SQL injection is prevented by parameterized queries/prepared statements, not by string escaping alone; XSS is mitigated by output encoding.

• Phishing exploits human trust; social engineering bypasses technical controls, so security awareness training is a control.

• Privacy principles: data minimization, purpose limitation, consent, and the right to access or delete personal data.

• Copyright protects expression, not ideas; software licensing (proprietary, open source, freeware) defines permitted use and redistribution.