Ciphers

A coded message makes the perfect clue for an escape room: print it, hide it, and only those who can decode it will understand it. Here are classic ciphers to use in class. Each one has a tool to encode and decode on the spot, and its key table.

• Caesar cipher

  Every letter moves the same number of places along the alphabet.

  Easy · Historical

• Atbash

  The alphabet read backwards: A becomes Z, B becomes Y, and so on.

  Easy · Historical

• Substitution cipher

  Each letter becomes another, following a key you make up.

  Medium · Historical

• Morse code

  Letters, digits and signs as dots and dashes.

  Medium · Historical

• Number codes

  Letters as numbers: alphabet place, Unicode or bits.

  Easy · Modern

• Vigenère cipher

  A Caesar shift that changes from letter to letter, following a keyword.

  Hard · Historical

• Polybius square

  Each letter becomes two digits: its row and its column in a square of letters.

  Easy · Historical

• Mirror writing

  The message written back to front, to be read in a mirror.

  Easy · Historical

• Pigpen cipher

  Each letter becomes the lines around it in two grids and two X's.

  Easy · Historical

• Phone keypad

  Each letter is its key on an old mobile phone, pressed once per step.

  Easy · Modern