Introduction to IT Security: The CIA Triad

Concept of Security
- Security entails protecting secret information from unauthorized access.
- Examples of secret information include:
- Credit card information
- Health care information
- Passwords for various online accounts

Overview of the CIA Triad
- The CIA triad represents three main goals of IT security:
- Confidentiality
- Integrity
- Availability
- Note: CIA is an acronym and not related to the Central Intelligence Agency.

Definition of Confidentiality
- Measures taken to ensure that sensitive information is not disclosed to unauthorized individuals, entities, or processes.
- Involves preserving authorized restrictions on access and disclosure to maintain personal privacy and proprietary information security.
Importance of Confidentiality
- Essential to keep secret data secure and accessible only to authorized individuals.
- Controls used to maintain confidentiality include:
- Access Control
  - Limits access to data based on the security credentials of users (subjects) to the information (objects).
  - Examples include:
  - Passwords: Users need correct passwords for system access.
  - Biometric measures: Fingerprints or facial recognition for authentication.
- Access Control Lists (ACL)
  - Specifies who has permission to access certain files or resources.
  - Example: A user may receive an "access denied" message if they attempt to access restricted files.
- Encryption
  - Protects data being transmitted (e.g., using SSL or TLS) to ensure only authorized parties can read it.
  - Important during online transactions (e.g., purchasing products online).

Definition of Integrity
- Ensures that only authorized individuals can make changes to information, maintaining its reliability and accuracy.
- Emphasizes data accuracy and preventing unauthorized modifications.
Importance of Integrity
- Essential for maintaining accurate and consistent information within systems.
Mechanisms to Ensure Integrity
- Digital Signatures
- Used to verify the authenticity of the information and ensure it hasn't been altered or modified.
- Example: CEO's digital signature on memos guarantees that data is authentic and unchanged.
- Access Control
- Limits edit permissions based on user roles, ensuring only specific users can change critical information.
Differentiation between Confidentiality and Integrity
- Confidentiality relates to viewing data, while integrity relates to the alteration and manipulation of data.

Definition of Availability
- Ensures that data, systems, and services are accessible to authorized users when needed.
- An example of threats to availability includes:
- DDoS Attack (Distributed Denial of Service)
  - A malicious attack that floods traffic to a website, causing it to go offline and hindering business operations.
Importance of Availability
- Allows authorized users to access necessary information without downtime.
Strategies to Maintain Availability
- Building resilient systems that can continue functioning during failures:
- Use of dual power supplies for servers.
- Implement RAID systems for hard drives to ensure data redundancy.
- Regular backups to restore data in case of system failures.

Confidentiality
- Keep secret data secure and accessible only by authorized individuals.
Integrity
- Ensure only authorized changes are made to information, maintaining its accuracy and reliability.
Availability
- Guarantee that systems are online and accessible when needed, preventing unauthorized downtime.

All IT security measures studied in the course will focus on protecting these three key aspects:
- Preventing unauthorized access, manipulation, and maintaining high availability of systems.