Computer Security Overview

Computer Security Overview

• Refers to the protection of computer systems, networks, and data from unauthorized access, attacks, and damage.
• Also known as cyber security or IT security.
• Involves safeguarding hardware, software, and information from theft or damage.

Key Elements of Computer Security

• Confidentiality: Ensures information and resources remain concealed from unauthorized users.
• Integrity: Maintains the trustworthiness of data by preventing unauthorized or improper changes.
• Availability: Guarantees authorized users can access data when needed, ensuring the usefulness of the information.

Types of Attackers

• Hackers: Skilled individuals exploiting system vulnerabilities.
• Insiders: Authorized individuals who may misuse their access.
• State-sponsored Actors: Highly trained cyber spies working for governmental entities.

Security vs. Usability Trade-off

• Balancing strong security measures with user-friendliness is crucial.
• Increased security often leads to user inconvenience.

Security Attacks

• Malware: Compromises data, steals information, or disrupts operations (e.g., viruses, ransomware).
• Phishing: Tricks users into revealing personal information via counterfeit websites.
• Denial-of-Service (DoS): Overwhelms a web service to disrupt normal operations (e.g., DDoS attacks).
• Man-in-the-Middle (MitM): Eavesdrops on communication between two parties.
• SQL Injection: Targets databases by injecting malicious SQL to manipulate or access data.
• Cross-Site Scripting (XSS): Injects scripts into web applications to execute in user browsers.
• Data Breaches: Unauthorized access to sensitive data, often exposing personal information.
• Insider Threats: Misuse of authorized access by individuals within an organization.
• Social Engineering: Manipulates individuals into divulging confidential information.

Security Mechanisms

• Access Control: Limits resource access to authorized users through authentication and authorization methods.
• Encryption: Converts data into scrambled formats, making it accessible only to authorized parties with the correct decryption key.
• Firewalls: Monitor and control network traffic, protecting against unauthorized access.
• Intrusion Detection and Prevention Systems (IDPS): Monitor networks for suspicious activities to prevent breaches.
• Vulnerability Assessment: Regular scanning to identify and address system weaknesses.
• Security Policies: Guidelines outlining organizational security practices and responsibilities.
• Multi-Factor Authentication (MFA): Requires multiple verification forms to access sensitive information.
• Audit Trails: Track user activities for investigation and review of security incidents.
• Backup and Disaster Recovery: Regular data backups and plans for operational continuity post-incident.
• Application Security: Secure development practices to minimize vulnerabilities in software applications.

Symmetric Encryption

• Also known as "private key" encryption, utilizes a single key for both encryption and decryption.
• Block Algorithms: Encrypt data in fixed-size blocks using a secret key.
• Stream Algorithms: Encrypt data in a continuous stream.
• Common symmetric encryption algorithms include AES, DES, and Blowfish.

Cryptography

• The technique of encoding data to ensure that it remains confidential, integral, authentic, and non-repudiated.
• Key uses: maintaining data confidentiality, integrity, authentication, and non-repudiation.

Attacks on Encrypted Messages

• Brute Force Attack: Attempts all possible keys to decrypt messages.
• Known-Plaintext Attack: Uses known pairs of plaintext and ciphertext to determine keys.
• Chosen-Plaintext Attack: Allows attackers to choose plaintexts and analyze corresponding ciphertexts.
• Frequency Analysis: Exploits predictable patterns in natural language for deciphering codes.

Random Numbers in Encryption

• True Randomness: Generated via hardware from unpredictable physical processes.
• Non-Random Values: Keys based on predictable inputs (like current date/time) are weak.
• Pseudorandom Numbers: Generated via algorithms that seem random but are based on an initial seed.

Cryptanalysis and Its Users

• Employed by hackers, government entities, and cybersecurity companies to break encryption and analyze data security.

This quiz covers the foundational elements of computer security, including its key components such as confidentiality, integrity, and availability. You will also learn about different types of attackers and the balance between security and usability. Test your knowledge and understanding of cyber security concepts.