LSPRO can encrypt and decrypt the xml content on the fly
If the url contains $$LSProEncKey=....$$ then it will assume that the data is encoded (LSProEncKey part of the url will not be sent to the server). It expect that the url to return base64 data using AES with ECB encryption, 128 bit. To create that data, go to http://aesencryption.net/ and enter the plain text (xml) there, enter any key (not more than 16 chars) and make sure to select 128 bit option and click encrypt (you can do this same thing in any free utility or python program/php code to encrypt the data).
After that if you enter the url in the lspro or via external link and use LSProEncKey then it will do the decryption on the fly.
Example:
<item>
<title>enc test</title>
<link>ignore</link>
<externallink>http://pastebin.com/raw/1fhhhRiM$$LSProEncKey=thisismytest$$</externallink>
</item>
