Demo hill-climber

Here's a demo program that uses PH hill-climbing to attempt to solve Playfair ciphers. The program is written in javascript and uses HTML 5 "web workers". Unfortunately it is not compatible with the Internet Explorer web browser. But it will run on any of these web browsers: Chrome, Firefox, Safari, Opera.

Notes:

(1) The program is set to use 3 hill-climbers. If your computer does not have a multi-core CPU it may be more efficient to choose just 1 or 2 hill-climbers.

(2) You can change the fudge factor settings. Many solutions occur when the percentage of accepted keys is between 3 and 4. If your % accepted is a lot different than this you might want to change the fudge factor settings.

(3) You can change the number of trial decrypts per hill-climber. For difficult ciphers you may want to increase this number so the program will generate more trial decrypts before it halts.

(4) The program assumes that the plaintext is in English. For other languages you may want to use a custom tetragraph table. The program has an option to load a book in the language in question.

(click here for direct link)