JScript.Encode

JScript.Encode is a method created by Microsoft used to obfuscate both server and Client-side JavaScript or VB Script source code in order to protect the source code from copying.^[1] JavaScript code is used for creating dynamic web content on many websites, with the source code easily viewable, so this was meant to protect the code.

The encoding is a simple polyalphabetic substitution using three alphabets.^[2]

How to use

A command line script encoder can be used to encode scripts.^[1][3] To encode a HTML web-page file called default.htm, use the following command:

screnc.exe default.htm defaultenc.htm

It would output to a file called defaultenc.htm.

Weaknesses

It has been reverse engineered^[2] and many websites provide an on-the-fly decoder.^[4]