Why This Topic Is Important for ECET?
IoT is everywhere—Smart homes, sensors, automation, industry, and healthcare.
ECET frequently asks theory + application-based questions on:
- IoT architecture
- Security threats
- Authentication
- Encryption
- Vulnerabilities in IoT devices
Understanding IoT Security is essential to score easy direct questions + conceptual MCQs.
📘 Concept Notes – IoT Security
IoT Security refers to protecting IoT devices, networks, data, and users from cyber-attacks.
1. Why IoT Needs Security?
Because IoT devices:
- Have low computational power
- Use wireless communication
- Often lack strong encryption
- Are deployed in unprotected environments
This makes them easy targets for:
- Unauthorized access
- Data theft
- Device hijacking
- Distributed denial-of-service (DDoS) attacks
Example:
A hacked smart thermostat can give access to the entire home network.
2. Common IoT Security Threats
a) Device-Level Threats
- Weak passwords
- Outdated firmware
- Hardware tampering
b) Network-Level Threats
- Eavesdropping
- Man-in-the-middle attack
- Packet sniffing
- Fake node injection
c) Cloud-Level Threats
- Unsecured APIs
- Poorly configured databases
3. IoT Security Mechanisms
A) Authentication
Ensures the device/user is genuine.
Methods: Password-based, token-based, biometric, OTP, certificates.
B) Encryption
Protects data during transmission.
Example formulas:
C) Access Control
Defines who can access which resource.
Models: RBAC, ABAC, MAC.
D) Secure Communication Protocols
- HTTPS
- TLS/SSL
- MQTT with TLS
- CoAP with DTLS
E) Firmware & Software Updates
OTA (Over-the-Air) updates protect devices from newly discovered threats.
4. Lightweight Security Algorithms
IoT devices need low-power security methods:
- AES-128
- ECC (Elliptic Curve Cryptography)
ECC signature formula:
where k = private key, P = generator point.
5. Real-Life Examples
- Smart cameras hacked due to default passwords
- IoT botnets like Mirai used for DDoS attacks
- Smart meters sending unencrypted data
⚙️ Formulas (QuickLaTeX Only)
AES encryption representation:
Decryption:
Hashing (SHA algorithm):
Digital Signature:
Public key verification:
ECC key generation:
🔟 10 MCQs (ECET + GATE Mixed Level)
Q1. Which layer is MOST vulnerable in IoT networks?
a) Application
b) Perception
c) Transport
d) Session
Q2. Encryption ensures:
a) Non-repudiation
b) Integrity
c) Confidentiality
d) Availability
Q3. Lightweight cryptography is needed in IoT due to:
a) High computational power
b) High memory
c) Low-power devices
d) Fast processors
Q4. AES uses which type of encryption?
a) Asymmetric
b) Symmetric
c) Hash-based
d) Quantum
Q5. ECC public key is generated by:
a) 
b) 
c)
d) 
Q6. Best protocol for secure IoT communication using UDP:
a) HTTP
b) CoAP + DTLS
c) MQTT without TLS
d) FTP
Q7. Mirai attack is an example of:
a) SQL injection
b) DDoS using IoT botnet
c) Wireless jamming
d) Device tampering
Q8. A hash function output is always:
a) Reversible
b) Variable length
c) Fixed length
d) Random length
Q9. If plaintext is encrypted using AES key K:
What is the correct decryption?
a) 
b)
c) 
d) 
Q10. IoT device identity verification is called:
a) Authentication
b) Authorization
c) Encryption
d) Hashing
✅ Answer Key (Table Format for WordPress)
| Q No | Answer |
|---|---|
| Q1 | b |
| Q2 | c |
| Q3 | c |
| Q4 | b |
| Q5 | c |
| Q6 | b |
| Q7 | b |
| Q8 | c |
| Q9 | b |
| Q10 | a |
🧠 Explanations
Q1: Perception layer is vulnerable because sensors are exposed physically → (b).
Q2: Encryption protects data from unauthorized reading → (c).
Q3: IoT devices have limited power → lightweight crypto required → (c).
Q4: AES is a symmetric block cipher → (b).
Q5: ECC key generation: → (c).
Q6: CoAP uses UDP; DTLS adds security → (b).
Q7: Mirai is a famous IoT botnet for DDoS → (b).
Q8: Hash functions always output fixed length → (c).
Q9: AES decryption formula → → (b).
Q10: Authentication identifies the device → (a).
🎯 Motivation / Why Practice Matters
IoT is a high-scoring area in ECET 2026.
Most questions come from:
- Security concepts
- Encryption basics
- Authentication methods
- IoT layers & vulnerabilities
Practicing these concepts improves:
- Speed in identifying correct answers
- Conceptual clarity
- Confidence during competitive exams
Master IoT Security → 100% guaranteed marks in this section.
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