CacheHackCacheHack
Back to Tutorials
Puzzle CreationIntermediate10 min read

How to Create a Puzzle Using Steganography

Steganography hides messages in plain sight—within normal-looking text, images, or other media. Unlike encryption, the goal is to conceal that a message exists at all.

Types of Text Steganography

  • Acrostics — First letters of lines/words spell a message
  • Null cipher — Read every Nth word or certain words only
  • Formatting tricks — Bold, italic, capitalised letters
  • Whitespace — Spaces, tabs, or invisible characters
  • Word patterns — Word lengths, syllable counts

1. Acrostic Messages

The classic approach: first letters of each line (or sentence, or word) spell a message.

Example (first letters of lines):

Never give up on your search
Often the answer is closer than you think
Remember to look around carefully
Take your time with each clue
Happiness comes to those who persevere

Hidden message: NORTH

Acrostic Variations

  • First letter of each word: "Notice Old Rocks Toward Hill"
  • Last letters: ReaN OilO CaR BiT HopeH
  • First letter of sentences: Longer text with hidden message
  • Middle letters: Much harder to spot

2. Null Cipher

Only certain words carry the message—the rest is padding to make it look natural.

Example (every 3rd word):

"The journey NORTH was exciting. Everyone arrived FIFTY minutes early. They discovered ONE hidden path."

Hidden message: NORTH FIFTY ONE

Null Cipher Patterns

  • Every Nth word: Regular intervals
  • Words after punctuation: After commas, periods, etc.
  • Pattern sequence: 1st, 3rd, 6th, 10th... (triangular numbers)
  • Keyword trigger: Word after specific words like "the" or "and"

3. Formatting-Based Steganography

Use text formatting to mark significant letters:

Bold/Italic Letters

"The curious traveller found the cluehidden in plain view."

= CACHE

Capitalisation

"some Outdoor activities Need To Have proper Equipment."

Capitalised letters: S O N T H E = SOUTH (rearranged)

Different Fonts/Colours

Use in digital puzzles where font changes are possible.

4. Whitespace Steganography

Invisible characters can encode binary data:

Space/Tab Binary

Space = 0, Tab = 1 (at end of lines or between words)

Zero-Width Characters

Unicode has invisible characters that can encode data

Line Spacing

Single vs double spacing to encode binary

Note: Whitespace methods can be disrupted by copy/paste or platform formatting. Test thoroughly before using.

Difficulty Variations

Easy (D1.5-D2)

  • • Obvious acrostic with title hint ("First Things First")
  • • Clearly formatted letters (bold/colour)
  • • Regular pattern (every Nth word)

Medium (D2.5-D3)

  • • Acrostic without hints
  • • Subtle formatting (slight font variation)
  • • Irregular but deducible pattern

Hard (D3.5+)

  • • Multiple steganography layers
  • • Whitespace encoding
  • • Complex patterns (Fibonacci, prime positions)
  • • Hidden in images using digital tools

Complete Example Puzzle

Cache Title: "A Letter to My Future Self"

Cache description:

"Dear future me,

Life has been an incredible journey so far.
Often I wonder where the path will lead.
Our adventures have only just begun.
Keep exploring, keep discovering.

Under the stars, I found peace.
Perhaps you'll find it too.

With hope,
Past Me"

Solution:

Title hints at "letter" = first letters
First letters of lines: L-O-O-K-U-P
Message: LOOK UP

Pro Tips

  • Make the cover text believable. If the visible text seems forced or awkward, solvers will spot the steganography faster.
  • Hint at the method. Even subtle hints help—"first things first," "read between the lines," "look closer."
  • Test on multiple platforms. Formatting can change when text is copied, viewed on mobile, or printed.
  • Don't make it too long. Long steganographic puzzles become tedious. Keep the hidden message short.