Here is a list of terms relating to puzzles and cryptography.


  • acrostic
  • A secret message spelled out with the first, last, or consistently numbered letters in a series of words. Taking the first letters of "sometimes evil cats ruin Eddie's toys" spells secret, while taking the third letters of "happy Ashley's purse flagrantly destroyed. Predictable!" spells phrase.

  • anagram
  • A word or phrase with its letters mixed up. To "anagram" something means to decode it by putting the letters in the proper order.

  • algorithm
  • A list of step-by-step instructions to accomplish a goal. For example, an encryption algorithm might look like this:

    1. remove all the spaces and punctuation
    2. remove all the e's
    3. reverse the letters in each word
    4. replace all the letters with numbers

    The corresponding decryption algorithm would be these same steps performed in reverse.

  • atbash cipher
  • A simple substitution cipher that swaps A for Z, B for Y, and so on. Try it!


  • backsolving
  • Usually an indication of a flawed puzzle, backsolving occurs when solvers determine the answer to a puzzle, and then work backwards to determine the solve method. Metapuzzles are often held in secret until their input puzzles have been completed, in order to prevent people from backsolving those input puzzles.

  • Beale ciphers
  • A set of three ciphers, described in an 1885 pamphlet, purporting to lead to a buried treasure that may or may not be a hoax. The second of these texts is a book cipher that uses a modified version of the American Declaration of Independence.

  • bigram/digram analysis
  • A method of letter frequency analysis.

  • binary
  • A base-2 numbering system that uses the digits 0 and 1. Binary is the mother tongue of modern computers, and occasionally appears as a code in puzzles.

  • Braille
  • A tactile code for blind and vision impaired people where a set of bumps represent letters and numbers. Braille characters are constructed from a 2x3 matrix of dots. Braille is commonly used in beginner puzzles.

  • brute force
  • A method of decrypting a message or solving a puzzle by inferring information, skipping over intended steps, or blindly trying every possible combination or input with the hope of stumbling upon the answer.

  • book cipher
  • This encryption method uses "addresses" or reference points to sections of a separate, usually well-known text. For example, "2:4:11:6," when applied to the Bible, might refer to the 6th word of the 11th verse of the 4th chapter of the 2nd book, Exodus, which is the word "him." The Bible is a common text used in book ciphers, as are plays by Shakespeare and various famous poems. The second page in the Beale ciphers uses the American Declaration of Independence.


  • Caesar cipher
  • Also called a "Caesar shift." An encryption method that shifts letters a certain number of places along the alphabet. For example, with a Caesar shift of 5, the letter A becomes F, B becomes G, and Z becomes E.

  • cipher/cypher
  • See code.

  • code
  • A method of representing information in a different format than it originally appears, often to hide or obfuscate the original message. Codes use algorithms to encrypt and decrypt the information reliably.

  • cracking
  • Solving/decrpyting a code.

  • cryptanalyst
  • Someone who studies the integrity of an information system for the purpose of defeating its security (perhaps in order to recommend further safeguards). Puzzle solvers and hackers are cryptanalysts.

  • cruciverbalist
  • A person who designs crossword puzzles.




  • flavour text
  • The written copy that accompanies a puzzle. Flavour text might flesh out a puzzle's story, or explain the the puzzle's rules. Hints are often hidden in flavour text.


  • game control
  • A puzzle hunt's team of organizers/event managers.

  • grille cipher
  • An encryption method that uses a perforated sheet or screen (the "grille") through which the intended message can be read.


  • hacker
  • A computer cryptanalyst.

  • hexadecimal
  • A base-16 numbering system that uses the digits 0-9, and the letters A-F to represent the values 10-16. Hexadecimal numbering most commonly appears in computer colour values (eg #00FF33).


  • indexing
  • A method of using numbers to select certain letters from a group. For example, the number 5 may be used to index the 5th letter in the alphabet. Or given the word "message" and the numbers 6-7-1, you might index the 6th, 7th, and 1st letters to spell gem.



  • key
  • A piece of information that is needed to decode a message. The use of keys in cryptography keeps the solve method (algorithm) safer, because even if the algorithm is discovered, the solver must still apply the correct key in order to decode the message. See Vigenère cipher for an example.


  • letter frequency analysis
  • A method of brute forcing a code by comparing the occurrence of certain symbols with commonly used letters. For example in English, the letter e occurs most commonly, so letter frequency analysis might determine that the most frequently used symbol in a code might represent e. This type of analysis can also be performed with common words in mind: a symbol on its own might represent the word "a," while three symbols frequently occurring together might represent the common words "the" or "and."


  • meta puzzle
  • A puzzle that requires information or solutions from one or more preceding puzzles before it can be solved. Because they employ information from other puzzles, they are wisely held back to prevent backsolving.

  • Morse code
  • A cipher that replaces letters and numbers with a series of dots and dashes that can be communicated in variety of ways: in written form, with audio, using flashing lights or eye blinks, or with electrical pulses, as in telegraphy.


  • NATO phonetic alphabet
  • A method of representing alphabet letters with words to avoid confusion while communicating, since many letters rhyme with one another (ie cee, zee, tee).

  • null cipher
  • A code in which a message is buried within a number of red herring, or "garbage," characters.



  • pigpen cipher
  • A code where letters are represented by their placements on grids reminiscent of tic-tac-toe boards. Also known as the masonic cipher, or the Freemason cipher.

  • prime numbers
  • Natural numbers greater than 1, the factors of which are only 1 and themselves. For example, no two natural numbers except 1 and 17 can be multiplied to form the prime number 17. Very larger prime numbers are a crucial component of cryptography, and form the basis of modern day online banking security. They appear in puzzles fairly regularly.

  • puzzle hunt
  • A live event where groups of solvers work in teams and compete to solve puzzles, which are usually acquired in different physical locations. Discovering the answer to one puzzle reveals the location of the next.



  • red herring
  • A puzzle element that has no bearing on the solution, and is included to confuse or mislead the solver.


  • semaphore
  • A maritime code that translates letters and numbers into the positions of two flags held at different points in an 8-point circle. Semaphore is frequently found in puzzles, and can be obfuscated as clock hands or cardinal directions.

  • steganography
  • A method of hiding a message "in plain sight" within another message, without raising the suspicion that a hidden message even exists.

  • substitution cipher
  • A simple code where one thing stands in for another. For example, numbers may stand in for letters. Braille and Morse code are well-known substitution ciphers.