Steganography

Steganography is the art and science of hiding a secret message, file, or data within an ordinary, non-secret file or message, known as the carrier or covertext. Unlike cryptography, which scrambles a message to make it unreadable but does not hide its existence, steganography's primary goal is to conceal the very fact that a secret communication is occurring. This is often achieved by subtly altering the data of a carrier file, such as an image, audio, or video file, in ways that are imperceptible to human senses, for instance, by modifying the least significant bits of pixel data in a picture. In cybersecurity, this technique can be used by malicious actors to exfiltrate data or deliver malware undetected, or by legitimate parties to protect sensitive communications from surveillance.

1. Introduction to Steganography
   1. Defining Steganography
      1. Etymology and Historical Context
      2. Distinction from Related Fields
         1. Cryptography
         2. Watermarking
         3. Data Hiding
         4. Information Security
   2. Core Principles
      1. Secrecy of Communication
         1. Concealment vs. Encryption
         2. Covert Communication Channels
      2. Imperceptibility
         1. Human Perception Limitations
            1. Visual Perception Thresholds
            2. Auditory Perception Limits
            3. Cognitive Processing Constraints
         2. Statistical Indistinguishability
            1. First-Order Statistics
            2. Higher-Order Statistics
            3. Distribution Preservation
      3. Capacity
         1. Trade-offs with Imperceptibility
         2. Measuring Payload Size
            1. Absolute Capacity
            2. Relative Capacity
            3. Effective Capacity
         3. Capacity Bounds
      4. Robustness
         1. Resistance to Modification
            1. Intentional Attacks
            2. Unintentional Modifications
         2. Resilience to Compression and Noise
            1. Lossy Compression Effects
            2. Channel Noise Impact
            3. Signal Processing Operations
   3. Steganography vs. Cryptography
      1. Goals and Objectives
         1. Confidentiality
         2. Concealment of Existence
         3. Authentication
         4. Integrity
      2. Visibility of Communication
         1. Detectability of Encrypted vs. Hidden Data
         2. Suspicion Avoidance
      3. Combined Usage
         1. Crypto-Steganography Concepts
         2. Layered Security Approaches
         3. Defense in Depth
   4. Key Terminology
      1. Cover Medium
         1. Covertext
         2. Cover File
         3. Cover Object Properties
      2. Stego-Medium
         1. Stegotext
         2. Stego File
         3. Stego Object Characteristics
      3. Payload
         1. Secret Message Types
            1. Text Messages
            2. Binary Data
            3. Executable Code
            4. Multimedia Content
         2. Payload Size Considerations
            1. Maximum Capacity
            2. Optimal Payload Size
      4. Steganographic Key
         1. Key Generation
            1. Random Key Generation
            2. Deterministic Key Derivation
         2. Key Distribution
            1. Secure Key Exchange
            2. Key Management Protocols
      5. Embedding Algorithm
         1. Embedding Process Overview
         2. Embedding Strategies
         3. Error Correction Integration
      6. Extraction Algorithm
         1. Extraction Process Overview
         2. Blind vs. Non-blind Extraction
         3. Error Detection and Correction