API Security

API Security is the specialized practice within cybersecurity focused on protecting Application Programming Interfaces (APIs), the critical communication pathways that allow different software applications to connect and share data. As APIs expose application logic and sensitive data, they have become a primary attack vector for malicious actors seeking to exploit vulnerabilities such as broken authentication, excessive data exposure, injection flaws, and improper asset management. The discipline involves implementing robust policies, authentication, authorization, and traffic management controls to prevent data breaches, unauthorized access, and denial-of-service attacks, ensuring the integrity and confidentiality of the services foundational to modern web, mobile, and microservices architectures.

1. Introduction to API Security
   1. Understanding APIs
      1. API Fundamentals
         1. Definition and Core Concepts
         2. API Terminology
         3. Request-Response Model
         4. Endpoints and Resources
      2. API Types by Access Level
         1. Public APIs
         2. Private APIs
         3. Partner APIs
         4. Internal APIs
      3. API Types by Architecture
         1. Web APIs
         2. Library APIs
         3. Operating System APIs
         4. Database APIs
      4. Role in Modern Software Architecture
         1. Microservices Communication
         2. Mobile Application Backends
         3. Third-Party Integrations
         4. Cloud Service Connectivity
      5. Communication Patterns
         1. Synchronous Communication
         2. Asynchronous Communication
         3. Request-Response Patterns
         4. Event-Driven Patterns
      6. Data Exchange Formats
         1. JSON
         2. XML
         3. Protocol Buffers
         4. MessagePack
   2. API Security Landscape
      1. APIs as Attack Vectors
         1. Attack Surface Expansion
         2. Data Exposure Risks
         3. Business Logic Vulnerabilities
      2. Common Attack Scenarios
         1. Data Breaches Through APIs
         2. Unauthorized Access
         3. Service Disruption
         4. Business Logic Exploitation
      3. Impact of API Security Breaches
         1. Data Loss and Exposure
         2. Financial Consequences
         3. Reputational Damage
         4. Regulatory Penalties
         5. Operational Disruption
   3. API Architectural Styles
      1. REST Architecture
         1. REST Principles
         2. Resource-Based Design
         3. HTTP Methods and Status Codes
         4. Stateless Communication
         5. Common Implementation Patterns
      2. GraphQL
         1. Query Language Fundamentals
         2. Schema Definition
         3. Resolvers and Data Fetching
         4. Differences from REST
         5. Security Considerations
      3. gRPC
         1. Protocol Buffer Definition
         2. Service Definition
         3. Streaming Capabilities
         4. Performance Characteristics
         5. Security Features
      4. SOAP
         1. XML-Based Messaging
         2. WSDL Service Description
         3. Built-in Security Standards
         4. Enterprise Integration Patterns
      5. WebSocket APIs
         1. Full-Duplex Communication
         2. Connection Management
         3. Real-Time Data Exchange
         4. Security Challenges