webcrypt - Instructions

1. Download either the zip version or that tar-ball version of webcrypt and un-zip/tar into a Java-installed system (you need Java 1.4 or higher).
2. In the top-level of your newly created directory you'll see the class-file Browse.class (and java source Browse.java). To start the program use the command java Browse from the top-level of the new directory.
3. Browser features:
   1. You may go directly to any URL by typing it into the text-field and hitting ENTER
   2. "BACK"/"FORWARD" buttons work as in most browser
   3. "RELOAD" button reloads the page -as html- even if you are viewing its source
   4. "HOME" takes you to our course homepage
   5. "ASSIGNMENTS" takes you to our homework directory
   6. "SOURCE" lets you view the source of any page (this may be useful for understanding how the mark-up symbols get transformed under a particular ciphers)
   7. "CRYPTO" pops up a window which lets you apply an encryption or decryption algorithm to the web-page's source.
   8. "ANALYZE" pops up a window containing some statistical tools for attempting to cryptanalyze an encrypted page
   9. "FILE" - allows you to open a local file or save a web-page locally. NOTE: there is some confusing behavior in the way this works, which I will now explain:
      • At first, you may not see the files/directories that you are looking for. FIX:
        1. Be sure to select "File of Type: All Files" (otherwise it anly lists HTML files)
        2. Go up higher in the file system by clicking on the "Up One Level" icon
      • When you encrypt or decrypt a file, nothing destructive happens. To make permanent changes you need to SAVE the file.
      • When you save a file, you do not actually point your browser to that file. You are still viewing the original source before the encryption/decryption. (This allows multiple encryption attemps of the same file).
      • If you want to view your encrypted/decrypted file, you should OPEN the file that you just saved.
   10. Some cryptanalyses may be eased by using fixed-width fonts. Choose "THEMES" and then "FIXED WIDTH"
4. Specific details about how to use webcrypt will be available in the cryptanalysis lecture

Note on the source-code for Webcrypt

The Webcrypt browser is a modification of an open-source Java web browser created by David Flanagan and described in his book Java Examples in a Nutshell (actually the code was taken from the 2nd edition). I took Flanagan's code and added functionality for encrypting/decrypting web-pages, as well as some statistical tools for cryptanalyzing the included ciphers.