Steganography
Hide and extract secret messages inside images using LSB (Least Significant Bit) encoding.
Choose an image, enter your text, then click Encode. Larger messages require bigger images.
Upload a stego-image and click Decode to reveal any hidden message.
How it works
LSB steganography hides data in the least significant bit of each color channel (R, G, B) of every pixel. The change in color is imperceptible to the human eye (1 bit out of 8 per channel = 0.39% change).
Capacity: the image can hide up to ((width × height × 3) / 8) - 8 UTF-8 bytes. A 100×100 pixel image holds ~3,742 bytes. Encoded output is saved as PNG (lossless - JPEG would destroy the LSB data).
For CTF: tools like StegSolve, zsteg, and stegseek can analyze and crack password-protected LSB steganography.
Note: LSB steganography without encryption is easily detected. Always encrypt the message before hiding it if confidentiality matters.