Stego Lab

Hide and find data in images — real LSB steganography & steganalysis

SY0-701 1.4 · obfuscation: steganography
Missions 0 / 4
Security+ Hub

Mission 1 — LSB Embed

A cover image is generated in-browser. You type a secret message, click Embed, and the lab writes your message into the least-significant bits of the pixel RGB values via getImageData / putImageData. The cover and stego images are displayed side-by-side; they look identical to the eye.

Objective: embed a secret message into the cover image and confirm the two images are visually indistinguishable — then advance to Mission 2 to prove the data is really in there.

LSB principle: each RGB byte is 8 bits; changing only bit-0 moves the colour value by at most 1 in 255 — below the threshold of human perception. The image hash, however, will differ (proven in Mission 3).

Mission 2 — LSB Extract

The stego image you created in Mission 1 is still in memory. Now read the least-significant bits back out and reconstruct the original message. If the round-trip is perfect (extracted text equals what you embedded), the mission passes.

Objective: extract the hidden message from the stego-object and confirm it matches the embedded text exactly. A wrong message or an empty carrier cannot pass.
Embed a message in Mission 1 first
nothing extracted yet
embed in Mission 1 to populate

Round-trip integrity is the ground truth: the extracted string must be byte-identical to what was embedded. Any bit error in the carrier or off-by-one in the framing protocol fails the decode.

Mission 3 — Steganalysis & Hash Proof

A defender needs to detect hidden payloads without already knowing the message. Two techniques: (1) LSB bit-plane amplification — stretch the LSB plane so 0 = black, 1 = white; a natural image looks like random noise, but one with a sequential payload shows a structured band. (2) SHA-256 hash — the cover and stego images have identical visual appearance but different hashes, proving the change is invisible to the eye yet detectable by integrity tools.

Objective: (a) decide which of the two mystery images carries a payload; (b) observe the hash difference. Both gates must pass to complete the mission.

Amplification: each pixel's R value is replaced with 255 * (R & 1) — pure white if LSB=1, black if LSB=0. A payload written sequentially produces a structured band at the top; an unmodified image produces random salt-and-pepper.

Image A Image B
Cover image SHA-256
embed in Mission 1 first
Stego-object SHA-256
embed in Mission 1 first

SY0-701 1.4 notes steganography as an obfuscation technique alongside tokenization and data masking. Unlike encryption, a stego image produces no obvious ciphertext — but the hash still betrays modification to any integrity system.

Mission 4 — Technique Vocabulary

You've embedded, extracted, and detected hidden data. Now map the exact terminology to its definition. These terms appear verbatim in SY0-701 domain 1.4 (Cryptographic Solutions) under the obfuscation sub-heading. Every row must be correct; picking even one wrong option fails the review.

Objective: match all six terms to their definitions. Confusing steganography with cryptography, or carrier with payload, fails the mission.

Stego Lab certified

You embedded a secret into real pixel data, recovered it bit-perfect, detected a payload via LSB bit-plane amplification, proved integrity divergence with SHA-256, and mapped the SY0-701 1.4 obfuscation vocabulary. That is the full steganography discipline in one engine.

Steganography · obfuscation LSB embed / extract Steganalysis · bit-plane SHA-256 integrity proof SY0-701 1.4