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Glossary

Shadowforge Terminology and Concepts

Core Concepts

Steganography

  • Practice of hiding data within non-secret data in such a way that the very existence of the hidden data is concealed
  • Different from cryptography (which obscures data) - steganography hides data
  • Goal: Covert communication with minimal detectability

Stego (Stego Media)

  • The output file containing both the original carrier and the hidden payload
  • Appears to be innocent media (image, audio, text) to observers
  • Contains encrypted payload + Reed-Solomon parity data

Carrier / Cover Media

  • The original innocuous media file used to hide data
  • Can be image (PNG, JPEG, GIF), audio (WAV), or text (TXT)
  • Selected to have sufficient capacity for the payload

Payload

  • The secret data being hidden
  • Encrypted using Kyber-1024 KEM before embedding
  • Encoded with Reed-Solomon error correction before steganographic embedding

Cryptography

Post-Quantum Cryptography (PQC)

  • Cryptographic algorithms believed to be resistant to quantum computer attacks
  • Kyber-1024 and Dilithium3 are NIST-approved post-quantum standards
  • Shadowforge uses these for quantum-resistant security

Kyber-1024

  • Post-quantum key encapsulation mechanism (KEM)
  • Generates ephemeral shared secrets for AES-256 encryption
  • Equivalent to 3072-bit RSA in classical security strength
  • NIST standard for public-key encryption

Dilithium3

  • Post-quantum digital signature algorithm
  • Used for payload signing and integrity verification
  • NIST standard for digital signatures
  • Resistant to future quantum attacks

Key Pair

  • Public key: Can be shared openly, used for encryption
  • Private key: Must be kept secret, used for decryption and signing

Encapsulation

  • Process of generating a shared secret using a public key
  • Used in Kyber to establish encryption key for AES-256
  • Different encapsulation produces different ciphertext from same message

Error Correction

Reed-Solomon (RS) Encoding

  • Forward error correction code used for data resilience
  • Creates parity shards allowing recovery from missing or corrupted data
  • Shadowforge uses RS to enable multi-carrier distributions

Shard

  • One piece of Reed-Solomon encoded data
  • Multiple shards can reconstruct original data if K shards are available
  • Total shards = data shards + parity shards

K-of-N Threshold

  • Recovery requires K (minimum) of N (total) shards
  • Example: 10-of-15 means any 10 of 15 shards can recover data
  • Redundancy = (N-K) / N

Redundancy Level

  • Percentage of additional shards for error correction
  • 30% redundancy = 3 parity shards per 10 data shards
  • Higher redundancy = better loss tolerance, larger data overhead

Steganography Techniques

LSB (Least Significant Bit)

  • Modifies the least significant bit of pixel/sample values
  • Imperceptible changes to human perception
  • Works with: Images (PNG, JPEG, BMP, GIF), Audio (WAV)
  • Capacity: High, Security: Medium

DCT (Discrete Cosine Transform)

  • Modifies coefficients in DCT-transformed JPEG blocks
  • Middle-frequency coefficients for imperceptibility
  • Works with: JPEG images
  • Capacity: Medium, Security: High

Phase Encoding

  • Modifies phase spectrum of audio using FFT
  • Preserves magnitude while encoding in phase differences
  • Works with: Audio (WAV)
  • Capacity: Medium, Security: Excellent

Echo Hiding

  • Encodes data using different echo delays
  • Binary 0 = short delay, Binary 1 = long delay
  • Works with: Audio (WAV)
  • Capacity: Low, Security: Excellent

Zero-Width Characters

  • Uses invisible Unicode characters (ZWSP, ZWJ) to encode data
  • Completely invisible to human reading
  • Works with: Text (TXT, documents)
  • Capacity: Very Low, Security: Perfect for metadata

Palette-Based

  • Reorders color palette or modifies palette entries
  • Works with: GIF, PNG (with indexed color)
  • Capacity: Medium, Security: Good

Distribution Patterns

One-to-One (1:1)

  • Single payload embedded in single carrier
  • Basic distribution pattern
  • Simplest to use, good for small data

One-to-Many (1:N)

  • Single payload split across multiple carriers using Reed-Solomon
  • Data shards + parity shards distributed
  • Enables resilience: loss of parity shards is acceptable
  • Good for distribution resilience

Many-to-One (N:1)

  • Multiple payloads aggregated into single carrier
  • Creates payload index for selective extraction
  • Good for multiple small files

Many-to-Many (N:M)

  • Multiple payloads distributed across multiple carriers
  • Complex distribution requiring sophisticated coordination
  • Good for scenarios requiring both redundancy and scalability

Advanced Concepts

Technique Chaining

  • Combining multiple steganography techniques
  • Sequential: Apply one technique, then another
  • Layered: Different portions with different techniques
  • Split: Distribute across multiple carriers with different techniques

Detectability Score

  • Numerical measure (0.0-1.0) of how detectable an embedding is
  • < 0.30: Very secure (excellent stealth)
  • 0.30-0.70: Acceptable security

  • 0.70: Risky (high detectability)

  • Calculated using statistical analysis

Chi-Square Analysis

  • Statistical test for detecting anomalies in data distribution
  • Compares observed distribution to expected distribution
  • High chi-square value indicates possible steganography

Capacity (Embedding Capacity)

  • Amount of data that can be hidden in a carrier
  • Depends on: technique, carrier type, carrier size, quality requirements
  • Measured in bytes or percentage of carrier size
  • Safe capacity = calculated capacity × 0.7

Entropy

  • Measure of randomness/disorder in data
  • High entropy: Data looks random, harder to analyze
  • Low entropy: Data has patterns, easier to detect
  • Steganography attempts to preserve entropy to avoid detection

File Formats

PNG (Portable Network Graphics)

  • Lossless image compression
  • Suitable for LSB steganography (preserves exact pixels)
  • Large file sizes for same resolution
  • Ideal for high-capacity hiding

JPEG

  • Lossy image compression
  • Suitable for DCT steganography (works with DCT coefficients)
  • Smaller file sizes
  • Trade-off: Some loss tolerance in DCT modification

GIF (Graphics Interchange Format)

  • Indexed color format (256 colors max)
  • Suitable for palette-based steganography
  • Good for animation sequences
  • Limited to 256-color palette

WAV (Waveform Audio)

  • Uncompressed audio format
  • Suitable for LSB, Phase, and Echo steganography
  • Large file sizes (176 KB/second at 44.1kHz stereo)
  • Good capacity for audio steganography

TXT (Text)

  • Plain text format
  • Suitable for zero-width character steganography
  • Very limited capacity
  • Useful for metadata and side-channel communication

Security Terms

Detectability

  • Likelihood that hidden data presence can be detected
  • Steganalysis: Attempting to detect steganography
  • Shadowforge minimizes detectability through technique choice

Steganalysis

  • Science of detecting steganography
  • Uses statistical analysis to find anomalies
  • Chi-square test, RS analysis, histogram analysis
  • Shadowforge designs techniques resistant to steganalysis

OPSEC (Operational Security)

  • Practices preventing information disclosure
  • Never share passwords on command line
  • Secure key storage and management
  • Proper file deletion and access control

Manifest

  • Metadata file describing shard distribution
  • Lists which shards are in which carriers
  • HMAC-protected against tampering
  • Keep separately from carriers

Deniability / Plausibility

  • Ability to deny hidden data exists
  • Unencrypted stego carrier can contain plausible content only
  • Not the same as encryption (encryption admits data exists)

Operations

Embedding

  • Process of hiding payload in carrier
  • Steps: Encrypt payload → Encode with RS → Apply steganography
  • Output: Stego file (innocent-looking carrier with hidden data)

Extraction

  • Process of recovering payload from stego file
  • Steps: Apply steganography extraction → Decode RS shards → Decrypt
  • Output: Original payload (if no corruption beyond parity capacity)

Analysis (Capacity)

  • Calculate how much data can hide in carrier
  • Depends on technique and quality requirements
  • Helps plan distribution patterns

Analysis (Detectability)

  • Calculate detectability score
  • Helps choose appropriate techniques
  • Guides capacity usage (use less than max capacity)

Distribution

  • Spreading data across multiple carriers
  • Uses Reed-Solomon for resilience
  • Enables one-to-many, many-to-one, many-to-many patterns

Reconstruction

  • Recovering original data from distributed shards
  • Uses Reed-Solomon decoding
  • Tolerates loss up to (N-K) shards

Abbreviations

Abbreviation Meaning Context
PQC Post-Quantum Cryptography Security algorithms
KEM Key Encapsulation Mechanism Kyber operation
RSA Rivest-Shamir-Adleman Classical (vulnerable) encryption
AES Advanced Encryption Standard Symmetric encryption used by Kyber
LSB Least Significant Bit Image/audio steganography
DCT Discrete Cosine Transform JPEG steganography
FFT Fast Fourier Transform Used in phase encoding
RS Reed-Solomon Error correction coding
GIF Graphics Interchange Format Image format
PNG Portable Network Graphics Image format
JPEG Joint Photographic Experts Group Image format
WAV Waveform Audio Format Audio format
ZWSP Zero-Width Space Unicode character U+200B
ZWJ Zero-Width Joiner Unicode character U+200D
HMAC Hash-based Message Authentication Code Integrity protection

Measurement Units

  • Byte: 8 bits of data
  • KB: Kilobyte (1,024 bytes)
  • MB: Megabyte (1,024 KB)
  • Capacity percentage: Percentage of carrier size usable for data
  • Detectability score: 0.0 (undetectable) to 1.0 (highly detectable)

Glossary for Shadowforge v1.0+ Last Updated: December 2025