Old Tricks · Family 5 · Secret Writing
The Cipher Room
Twenty real codes, cracked by real codebreakers. Now it's your turn.
Your rank
Clerk
Flags 0 / 20
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Ancient
Sparta, Greece
The Spartan Stick
Wrap the strip round the right rod. The words line up.
Scytale
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2nd century BC
Greece
Polybius's Torches
Read a night message sent by torches on a wall.
Polybius square
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about 50 BC
Rome
Caesar's Dispatch
Spin a cipher wheel, or let a computer try every key.
Brute force
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1467
Italy
Alberti's Disk
Turn the disk whenever a capital letter appears.
Cipher disk
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1500s
Italy
The Grille
Lay a mask with holes over a grid. Turn it. Read.
Turning grille
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1586
Chartley Hall, England
The Queen's Letter
A letter in symbols. Count them and the language breaks.
Frequency analysis
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1700s
Trinity Churchyard, New York
The Graveyard Stone
Two words on an old gravestone, carved in a secret alphabet.
Pigpen
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1790s
USA
Jefferson's Wheel
Spin ten disks, then scan the rows for English.
Wheel cipher
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1843
Edgar Allan Poe
The Gold-Bug
A pirate's cipher with no spaces. Find the hidden words.
Frequency analysis
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1868
Lewis Carroll
The Alphabet Cipher
Find the repeats. They reveal the length of the key.
Kasiski test
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1885
Virginia
The Beale Treasure
Numbers point to words. The first letters spell the secret.
Book cipher
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1903
Arthur Conan Doyle
The Dancing Men
Stick figures that dance. Each pose is a letter.
Figure code
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1912
North Atlantic
The Last Signal
Lights and beeps from a ship in trouble. Read the Morse.
Morse code
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1917
Room 40, London
The Zimmermann Telegram
Numbers on a telegram. Find the words in the codebook.
Codebook
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1918
France
Painvin's Breakthrough
Put the columns in order and the pairs become letters.
ADFGVX
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1940s
Bletchley Park
The Weather Report
Slide a guessed word along Enigma code, then run the Bombe.
Crib and Bombe
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1940s
Venona project
The Reused Pad
Two secrets, one key. Slide a guess and both leak.
Reused pad
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2010
Your pocket
The Smudged Phone
Finger grease on a screen gives away the unlock pattern.
Smudge attack
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2012
LinkedIn
The Leaked Passwords
Test common passwords against a stolen list. Then add salt.
Hash cracking
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Today
Social media
The Hidden Pixel
A normal photo hides a message and a place.
Steganography
