From: DeskNow Knowledge Base
http://www.desknow.com/kb/

How to install the unlimited-strength encryption policy files
http://www.desknow.com/kb/idx/12/152/article/

These files allow DeskNow and java to use strong encryption algorithms for mail encryption and signing. These algorithms are normally not included in the standard Java SDK due to export restriction policies.

These policy files are already included in the Windows installer, so normally they're only required on Linux/Unix systems.

If you're using Java 1.4.2

download the 'Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files' from http://java.sun.com/j2se/1.4/download.html and follow the instructions. Then restart DeskNow.

If you're using Java 1.5 or later

download the 'Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files' from http://java.sun.com/javase/downloads/index.jsp and follow the instructions. Then restart DeskNow.