Information Security Notes
Subject Overview
Information Security covers core security concepts and principles, security threats/
Subject at a glance
4
Units
32
Topics
5
Credits
4
Infographics
Unit-wise Syllabus
4 units — open any unit for detailed topic-wise notes, diagrams and important exam questions
- Security overview and background
- principles of security
- information classification
- policy framework
- role-based security
- components of information systems
- balancing security and access
- security implementation approaches
- security systems development life cycle
Confidentiality
Only authorised people can see data
Integrity
Data is not altered improperly
Availability
Data and systems are there when needed
Study guide
This unit introduces security: its principles, information classification, policy framework, role-based security, components of information systems, balancing security and access, implementation approaches and the security systems development life cycle. Learn the CIA triad: confidentiality, integrity and availability.
- Intruders
- malicious software
- viruses and related threats
- desktop security
- email security (PGP and S/MIME)
- web security (authentication, SSL, SET)
- database security
- firewall overview/design principles/types
Virus
Attaches to files and spreads
Worm
Spreads by itself over networks
Trojan
Hides inside useful-looking software
Ransomware
Encrypts data and demands payment
Phishing
Fake messages to steal credentials
Study guide
You study threats and vulnerabilities: intruders, malicious software, viruses, desktop security, email security (PGP, S/MIME), web security (authentication, SSL, SET), database security and firewalls (design principles and types). Match each threat with the control that counters it.
- Access control and intrusion detection
- identification and authorization
- intrusion detection and prevention systems
- security procedures and best practices
- security laws
- IPR
- international security standards
- security audit
- SSE-CMM/COBIT
Full form
Intrusion detection system
Intrusion prevention system
Action
Detects and alerts
Detects and blocks
Placement
Monitors a copy of traffic
Inline with traffic
Risk
Attack may get through
False positives may block good traffic
Study guide
You study access control, intrusion detection and prevention systems, security procedures and best practices, security laws, intellectual property rights, international standards, security audit and SSE-CMM and COBIT. Know the main provisions of India's IT Act relevant to cybercrime.
- Cryptography concepts and techniques
- symmetric and asymmetric key cryptography
- steganography
- symmetric key ciphers (DES, AES structure and analysis)
- asymmetric key ciphers (public key cryptosystem principles, RSA algorithm)
- digital signatures
DES
Symmetric block cipher
56 bits: now insecure
AES
Symmetric block cipher
128, 192 or 256 bits
RSA
Asymmetric, public key
Typically 2048 bits or more
Study guide
You study cryptography: techniques, symmetric and asymmetric key cryptography, steganography, DES and AES, public key principles, the RSA algorithm and digital signatures. Work through a small RSA example by hand.
Why Information Security Matters
Cybersecurity is one of the fastest-growing and best-paid IT fields, with a global shortage of professionals. These fundamentals are the starting point for careers and certifications such as Security+ and CEH.
How to Prepare for Information Security
- Practise RSA key generation and encryption with small numbers.
- Learn the CIA triad and the types of attack with real examples.
- Follow cybersecurity news to see concepts in real incidents.
Information Security: Frequently Asked Questions
What is the CIA triad?
Confidentiality, integrity and availability, the three core goals of information security.
What is the difference between symmetric and asymmetric cryptography?
Symmetric cryptography uses one shared key for encryption and decryption, while asymmetric cryptography uses a public and private key pair.