Ch 12 covers security aspects of computing — types of cyber threats, protection mechanisms (encryption, firewalls, authentication), safe internet practices, and Indian cyber laws.
Malware: Virus (attaches to files, needs host, spreads on execution), Worm (self-replicating over network, no host needed), Trojan (disguised as legitimate software), Ransomware (encrypts files, demands ransom), Spyware (secretly monitors activity), Adware (unwanted ads). Attacks: Phishing (fake emails/websites stealing credentials), Denial of Service — DoS/DDoS (flood server with traffic), Man-in-the-Middle (intercept communication), Brute force (try all password combinations). Social engineering: manipulating humans rather than systems.
Encryption: Symmetric (same key for encrypt/decrypt — AES, DES; fast, key distribution problem), Asymmetric (public key encrypt, private key decrypt — RSA; slower, solves key distribution). Digital signature: verifies sender identity and message integrity. Firewall: monitors network traffic, blocks unauthorised access; types: packet filtering, stateful inspection, proxy. Antivirus/anti-malware: detect and remove malicious software. Safe practices: strong passwords, 2FA, regular updates, avoid suspicious links, backup data. Cookies: small data files stored by websites — first-party (same site) vs third-party (tracking). Indian IT Act 2000: Sections 43 (damage), 66 (hacking), 66C (identity theft), 66D (cheating), 67 (obscene content). DPDP Act 2023: consent-based data protection.
Download: https://ncert.nic.in/textbook/pdf/lecs112.pdf | Complete Book: https://ncert.nic.in/textbook/pdf/lecs1ps.zip
Virus: needs a host file (attaches to .exe, .doc etc.), spreads when infected file is executed/shared, user action required. Example: opening an infected email attachment. Worm: independent, self-replicating program, spreads over networks automatically, no user action needed. Example: exploiting a network vulnerability to copy itself to connected computers. Worms are generally more dangerous because they spread faster and autonomously. Both damage: data corruption, system slowdown, network congestion. Protection: updated antivirus, regular patches, don't open unknown attachments.
Book a Trial + Diagnostic session. Get a personalized Learning Path with clear milestones, tutor match, and a plan recommendation — all within 24 hours.
Book Trial + Diagnostic →