Standard Encoding

Standard Encoding

Standard encoding is the primary method for hiding data within images using QuantHide's post-quantum cryptography.

How It Works

┌─────────────┐    ┌──────────────┐    ┌─────────────┐
│  Your Data  │ -> │  Encryption  │ -> │ Steganography│ -> Encoded Image
│ (text/file) │    │  (Kyber1024) │    │    (LSB)     │
└─────────────┘    └──────────────┘    └─────────────┘

Step-by-Step Process

1. Data Preparation

   • Text messages are UTF-8 encoded
   • Files are read as binary data
   • Metadata (filename, size) is preserved for files

2. Encryption

   • Password → Argon2id → Key derivation
   • Kyber1024 encapsulation generates session key
   • ChaCha20-Poly1305 encrypts the data
   • Random padding added for security

3. Embedding

   • Encrypted data converted to bits
   • LSB (Least Significant Bit) encoding into image pixels
   • EXIF metadata stripped from output

Usage

Encoding a Message

1. Load Cover Image

   • Drag & drop or click to select
   • Supported: PNG, JPEG, BMP, WebP
   • Larger images = more capacity

2. Enter Your Message

   • Type in the message panel
   • Or switch to "File" tab to embed a file

3. Set Password

   • Strong password recommended
   • Same password needed for decoding

4. Click Encode

   • Wait for processing
   • Save the resulting PNG image

Encoding a File

1. Load cover image (same as above)
2. Click File tab in message panel
3. Click Select File or drag & drop
4. Set password
5. Click Encode

Best Practices

Choosing a Cover Image

Image Type	Recommendation
Photos	✅ Excellent - natural noise hides data well
Screenshots	⚠️ Okay - less natural variation
Solid colors	❌ Poor - changes more visible
Small images	❌ Limited capacity

Password Guidelines

• Minimum: 12 characters
• Recommended: 16+ characters
• Include: uppercase, lowercase, numbers, symbols
• Avoid: dictionary words, personal info

Output Format

• Always PNG - lossless compression preserves hidden data
• Original dimensions - image size unchanged
• No EXIF data - metadata stripped for privacy
• Slightly larger file - due to PNG encoding

Capacity

The amount of data you can hide depends on:

Capacity = (Width × Height × 3 channels × bits_per_channel) / 8 bytes

Example for a 1920×1080 image with 2 bits per channel:

1920 × 1080 × 3 × 2 / 8 = 1,555,200 bytes ≈ 1.48 MB

Note: Actual usable capacity is lower due to encryption overhead (~500 bytes for headers and authentication).

Troubleshooting

"Image too small for data"

• Use a larger cover image
• Reduce message/file size
• Try Split Encoding for large files

"Encoding failed"

• Check image format is supported
• Ensure image isn't corrupted
• Try a different cover image

Quality concerns

• Use high-resolution photos
• Avoid already-compressed images
• PNG sources work best

See Also

• Encryption Details
• Capacity Calculator
• Split Encoding
• Best Practices