Extracting Payloads

Supported Inputs

Extraction supports:

• stego images created with Stegodon
• stego WAV files created with Stegodon

Extraction Steps

1. Open the Extract tab.
2. Choose the stego file.
3. Enter the passphrase if one was used.
4. Click Extract.

What Stegodon Looks For

Stegodon begins by searching for its header.

The header starts with the magic value:

SGDN

If no valid header is found, extraction fails.

Header Discovery

For images

Stegodon tries combinations of:

• channel masks: RGB, R, G, B
• LSB depths: 1 and 2

It reads the beginning of the carrier and checks for the Stegodon magic bytes.

For WAV

Stegodon tries:

• 1-bit LSB
• 2-bit LSB

If the header is found, Stegodon parses the stored metadata.

Passphrase Requirements

A passphrase is required when the embedded payload used:

• randomized placement
• encryption
• or both

Randomized payloads

The passphrase is used to reconstruct the same shuffled position order.

Encrypted payloads

The passphrase is used to derive the AES-GCM key for decryption.

If the wrong passphrase is supplied, extraction will fail or decryption will throw an error.

Extraction Output

After extraction, Stegodon displays a result summary including:

• magic/version
• carrier type
• payload type
• whether randomization was used
• whether encryption was used
• LSB depth
• image channel mask, when relevant
• payload length
• original filename, when relevant

Text Results

If the payload was text, Stegodon attempts to decode the recovered bytes as UTF-8 and displays the result in a text area.

If text decoding is not clean, the UI may display a fallback note such as:

(binary text)

File Results

If the payload was a file, Stegodon creates a download link using the stored filename.

If no filename is present, it falls back to:

extracted.bin

Typical Extraction Errors

No Stegodon header found

The file likely was not created by Stegodon, or the embedded data was destroyed.

Passphrase required

A randomized payload was detected but no passphrase was supplied.

Decryption failure

The passphrase is wrong, or the payload was damaged.

Unsupported WAV

The file is not a supported PCM WAV input.

Why Extraction Can Fail

Extraction can fail if the stego file has been:

• resized
• recompressed
• edited
• converted to a lossy format
• partially corrupted

For example, saving a stego PNG as JPEG may destroy the hidden data.

Extraction Tips

• Use the original Stegodon output file
• Keep the original passphrase
• Do not edit the file before extraction
• Avoid format conversions
• If unsure whether the file contains a payload, run Detect first