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1. (a) What is a Transposition Cipher? Explain with an Example. (5 marks)
A Transposition Cipher is a method of encryption where the positions of the characters are shifted according to a regular system to form the ciphertext.
🔒 Important Note: Unlike substitution ciphers, transposition ciphers do not change the actual characters, only their positions.
Example (Columnar Transposition):
Plaintext: HELLO WORLD
Key: 4 (number of columns)
Arrange in a matrix (ignoring spaces):
H E L L
O W O R
L D X X ← X used to fill blank spaces
Read column-wise:
Column 1: H, O, L
Column 2: E, W, D
Column 3: L, O, X
Column 4: L, R, X
Ciphertext: HOL EWD LOX LRX → HOLEWDLOXLRX
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(b) What is Confidentiality and Availability of Data? How are They Ensured? (5 marks)
Confidentiality:
Ensures that only authorized users can access sensitive data.
✅ How to Maintain:
Encryption
Authentication (passwords, biometrics)
Access control policies
Secure communication (SSL/TLS)
Availability:
Ensures data and services are accessible whenever required.
✅ How to Ensure:
Redundancy (backup systems, failover servers)
Disaster recovery plans
Load balancing
Protection from DDoS attacks
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(c) Liabilities of Network Service Providers in Cyber Crimes (5 marks)
Network Service Providers (NSPs), like ISPs or hosting services, may be held liable if:
They knowingly allow their networks to be used for cybercrimes.
They fail to act even after being notified of unlawful activity.
Under the IT Act (Section 79):
NSPs are exempt from liability if they act as intermediaries without knowledge of the offense and exercise due diligence.
They must remove or disable access to illegal content once they are aware.
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(d) Trademark Infringement Related to Search Engines (5 marks)
Search engines can unintentionally promote trademark infringement through:
1. Keyword Advertising:
Using someone else’s trademark as a paid keyword (e.g., AdWords).
Competitors may show up when someone searches your brand.
2. Meta Tags:
Websites embed competitor’s trademarks in meta tags to manipulate search rankings.
3. Domain Name Abuse:
Creating domains like nike-sale-shoes.com without permission.
✅ Legal View: Courts consider if such use causes consumer confusion or dilutes brand reputation.
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2. Cyberspace Issues: (10 marks)
(a) Distributed Denial of Service (DDoS) Attack
A large number of compromised systems flood a server, causing it to crash or become unavailable.
(b) Malware
Malicious software like viruses, worms, trojans that damage systems or steal data.
(c) Cryptojacking
Unauthorized use of someone’s computer to mine cryptocurrency.
Victim’s system becomes slow and overheated.
(d) Cyber-Physical Attack
Attacks that affect physical systems through digital means.
Example: Stuxnet attack on Iranian nuclear plant.
(e) Phishing
Fake emails/websites designed to trick users into revealing credentials, banking info, etc.
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3. (a) Advantages & Disadvantages of Symmetric-Key Cryptography (5 marks)
✅ Advantages:
Faster encryption and decryption.
Efficient for large volumes of data.
Simple algorithms (e.g., AES, DES).
❌ Disadvantages:
Key distribution problem (must be shared securely).
Scalability issue (each pair of users needs a unique key).
No non-repudiation (can't prove sender's identity).
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(b) Security Measures: (2+2+1)
(i) Email Security (2 marks)
Use PGP, S/MIME for encryption.
Spam filters, virus scanning.
Two-factor authentication for login.
(ii) Anti-virus Protection (2 marks)
Detects and removes malware.
Real-time scanning and updates.
Quarantines suspicious files.
(iii) Access Security (1 mark)
Controls user access to systems.
Uses roles, permissions, multi-factor authentication.
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4. (a) Need for Regulating Cyberspace (5 marks)
Cybercrime Prevention: To punish and prevent hacking, fraud, data theft.
Protect Privacy: Ensure safe handling of personal data.
Digital Contracts: Provide legal recognition to electronic records and signatures.
International Trade: Harmonize laws for e-commerce.
National Security: Prevent cyber terrorism and espionage.
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(b) Role of Filtering Devices and Rating Systems in Legal & Self-Regulatory Frameworks (5 marks)
Filtering Devices:
Tools like firewalls, content filters block harmful or illegal content.
Used in schools, organizations to prevent access to adult or violent content.
Rating Systems:
Label websites/content (like UGC or gaming platforms) based on age or content type.
Examples: ICRA labels, PG/18+ tags.
✅ Purpose:
Help parents, ISPs, and users self-regulate access.
Aid legal enforcement and promote safe browsing.
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5. Explain the following terms (10 marks):
(i) Cyber Forensics
Process of collecting, analyzing, and preserving digital evidence.
Used in investigating cybercrimes like hacking or fraud.
(ii) Classification of Cyber Crimes
Against individuals: Cyberstalking, identity theft.
Against property: Hacking, data breaches.
Against government: Cyber terrorism.
Against society: Distribution of illegal content.
(iii) Domain Name Disputes
Conflicts over ownership/use of internet domains.
Example: Cybersquatting — registering famous brand names as domain names
to resell.
(iv) Framing
Technique of displaying content from one website within another using <frame> tags.
Used deceptively to divert traffic, steal clicks, or display ads fraudulently.
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