Access Control and Encryption Policies Quiz

Introduction to System Analysis and Design

• Course code: BIS301
• Lecture notes partly based on Ian Sommerville's work.
• Year: 2023

Software Security

• High priority for developers and users.
• Malicious attacks lead to losses, potentially business closure.
• Unavailability or data breaches can cause user cancellations.
• Recovery takes time and effort, better spent on software.

Types of Security Threats

• Availability threats: Prevent authorized users from accessing the system (e.g., Distributed Denial of Service attacks).
• Integrity threats: Damage the system or its data (e.g., viruses, ransomware).
• Confidentiality threats: Gain access to private information (e.g., data theft).

System Infrastructure Stack

• Operational environment
• Application
• Frameworks and application libraries
• Browsers and messaging system libraries
• Database
• Operating system
• Software infrastructure
• Network

Security Management

• Authentication and authorization: Strong authentication standards and proper permissions minimize unauthorized access.
• System infrastructure management: Configure infrastructure software and apply security updates promptly.
• Attack monitoring: Regularly check for unauthorized access and implement resistance strategies.
• Backup: Implement policies to maintain undamaged copies of program and data files.

Operational Security

• Focuses on user security.
• User attacks trick users into revealing credentials or accessing malware (e.g., key-logging).
• Procedures include automatic logouts in shared spaces, user command logging and multi-factor authentication.

Injection Attacks

• Malicious users insert malicious code or commands through valid input fields.
• Execution of these instructions causes damage to the system (e.g., buffer overflow and SQL poisoning attacks).

SQL Poisoning Attacks

• Attacks on SQL database systems.
• Malicious users input SQL fragments into form fields.
• These fragments modify queries to access unauthorized data.

Cross-Site Scripting Attacks

• Another form of injection attack.
• Attacker injects malicious Javascript code into web pages.
• Code executes in user's browser, potentially stealing information or redirecting to malicious websites.
• Stolen cookies allow session hijacking.
• Input validation can prevent these attacks.

Session Hijacking Attacks

• Attackers gain session cookie to impersonate a legitimate user.
• Multiple methods exist (e.g., cross-site scripting, traffic monitoring).
• Malicious code can steal session cookies from victims.
• Traffic monitoring intercepts client-server communication.

Actions to Reduce Hacking

• Traffic encryption: Use HTTPS to encrypt data transmission.
• Multi-factor authentication: Require multiple authentication factors to reduce risk from stolen credentials.
• Short timeouts: Set short session timeouts to prevent prolonged unauthorized access.

Denial of Service Attacks

• Attacks to make a software system unavailable for normal use.
• Distributed Denial of Service (DDoS) attacks use multiple computers or systems to overwhelm the server.
• Other types target application users (e.g., user lockout attacks, brute-force attacks using email addresses).

Brute Force Attacks

• Attackers repeatedly try different passwords until one works.
• Some use password lists and generators.
• Using strong, unguessable passwords reduces this risk.

Authentication

• Process to verify a user's identity.
• Essential in software that stores user information.
• Enables personalization of user experiences.

Authentication Approaches

• Knowledge-based: User provides personal information.
• Possession-based: Physical device authentication.
• Attribute-based: Biometric attributes (e.g., fingerprints).
• Multi-factor: Combines multiple authentication methods.

Password-Based Authentication Weaknesses

• Insecure passwords: Easy-to-guess or -remember passwords are vulnerable.
• Phishing attacks: Users clicking on fake links to collect credentials.
• Password reuse: Using same password across different sites increases vulnerability.
• Forgotten passwords: Issues with recovery mechanisms for stolen credentials.

Federated Identity

• Authentication approach using external authentication services.
• Example: Login with Google/Facebook.
• Single set of credentials stored by trusted identity service.
• Reduced risk of security breaches due to fewer storage locations.

Authorization

• Complementary process to authentication; controls access to system resources.
• Access based on user identity and defined policy.
• Example: Shared folder access permissions.

Access Control Policies

• Define access rights to resources.
• Ensure compliance with data protection rules.
• Starting point for system access control scheme.
• Define access rights for new users (e.g., students in a system).

Access Control Lists (ACLs)

• Tables that link users to resources, defining permissions.
• Defined permissions on files or databases.
• Access can be granular, based on individual or group permissions.

Encryption

• Process of making data unreadable to unauthorized users.
• Uses transformations with a secret key.
• Modern techniques are effective but technology advancements can make apparent security vulnerable.

Symmetric Encryption

• Same key for encryption and decryption.
• Securely sharing the key is problematic.
• Potential for interception compromising all future communications.

Asymmetric Encryption

• Different Keys for encryption and decryption. (Public/Private).
• Public keys can be distributed freely. Private keys are used to decrypt received messages containing a Public Key.
• Asymmetric keys can also verify a user's identity.

Encryption and Authentication

• Asymmetric encryption to verify sender identity.
• Bob uses private key to encrypt message.
• Alice decrypts it with Bob's public key, verifying correct identification.

TLS and Digital Certificates

• Standard for secure web communication.
• Verifies server identity.
• Uses digital certificates, issued by Certificate Authorities (CAs).
• Digital certificates are signed using the CA's private key and include the CA's public key to verify.

Data Encryption

• Encryption helps protect data from unauthorized access (in-transit, at rest and in-use).
• Important in cloud products.
• Prevents theft or use of sensitive data.
• Encrypting data at rest.
• Using HTTPS protocol for encrypting data in-transit.

Key Management

• Ensures that encryption keys are securely generated, stored and accessed.
• Automation is needed for large numbers of keys.
• Key Management System (KMS): Specialized database for storing and managing keys.

Long-Term Key Storage

• Regulations require data retention for several years.
• Using archival data with a different key reduces risks.
• Key Management Systems provide timestamped keys for backups and archives.

Privacy

• Social concept relating to how personal information is collected, shared, and used.
• Importance varies across cultures and individuals.
• User preferences should be reflected in privacy policies.

Business Reasons for Privacy

• Compliance with data protection regulations is essential.
• Privacy safeguards reduce legal risks for business users.
• Reputational damage can result from privacy leaks/misuse.

Data Protection Laws

• Laws in many countries define acceptable data collection, use, and handling. (e.g., GDPR).
• Example of restrictions on information usage is given in the slide which specifies that use of health information is only allowed to the extent user gave permission for advertising).
• Rules for data storage, use and subject access.

Privacy Policy

• Defines how personal and sensitive user data is managed.
• Should be clear, consistent and user-friendly (terms and conditions are generally not user-friendly).