Playfair Breaker

Quinapalus Home :: Things Cruciverbal :: Playfair Breaker

Playfair Breaker is a simple web page that helps you break Playfair codes.

The Playfair code is a simple encryption scheme frequently used in advanced crosswords. Here is an example, which includes an explanation of how the code works.

Playfair Breaker will search for Playfair keywords that take a given plaintext to a given ciphertext. Wildcards are allowed in the plaintext, and it is possible to break a code from ciphertext alone. A surprisingly short amount of ciphertext is required!

If you get stuck at any point, click on ‘Reset’: this will reset the options to their default settings.

How to use it

Simply enter the plaintext and ciphertext in the boxes provided and click on ‘Search’. If you don’t know the plaintext, leave it blank; if you know some letters of the plaintext, enter them and insert dots in the relevant positions to stand for the letters you don’t know.

Examples

For example, enter koeqlhaeospo in the ciphertext box and click on ‘Search’. See the results: the correct keyword, promise, appears as the fourth choice (using UKACD), with corresponding plaintext giantdespair.

Enter pb in the plaintext box and au in the ciphertext box to find keywords (which include doublespacing and tricephalous) that will transmute lead into gold. See the results.

Dictionaries

There is a choice of dictionaries to search; more information about them is available here. The default, UKACD, is suitable for most UK crosswords and similar puzzles. If the ‘with repeated letters disregarded’ box is unchecked, only words in the dictionaries that have no repeated letters are considered; otherwise, all words are considered with any repeated letters dropped. The ‘Multi-word’ dictionary contains some sequences of common words that have no repeated letters.

Presentation of results

Results are shown in decreasing order of the program’s evaluation of the resulting plaintext.


This page most recently updated Sat 22 May 10:34:33 BST 2021
Word Matcher

Options...
Type a pattern, e.g.
h???o
into the box and click ‘Go!’ to see a list of matching words. More...


Qxw screen
Qxw is a free (GPL) crossword construction program. New! Release 20200708 for both Linux and Windows. Non-Roman alphabets, batch mode, multiplex lights, answer treatments, circular and hex grids, jumbled entries, lots more besides. More...

You can order my book, ‘Practical Signal Processing’, directly from CUP or via Hive, Amazon UK or Amazon US.
Practical Signal Processing front cover
“Probably the best book on signal processing ever written” — review at Goodreads.
Wydanie polskie.

If you find this site useful or diverting, please consider a donation to NASS (a UK registered charity), to KickAS (in the US), or to a similar body in your own country.

Copyright ©2004–2021.
All trademarks used are hereby acknowledged.