Following are the two key differences found between these two configuration settings.
Unsecure Configuration of
Plugin Registration tool in CRM 2011
Secure Configuration of Plugin
Registration tool in CRM 2011
Unsecure configuration information could be read by any user in CRM. Remember its public information (Eg: Parameter strings to be used in plugin could be supplied here)
The Secure Configuration information could be read only by CRM Administrators.(Eg: Restricted data from normal user could be supplied here)
Imagine that you include a plugin, plugin steps and activate them in a solution. Later solution was exported as Managed Solution to another environment. In this scenario, the supplied Unsecure configuration values would be available in the new environment.
Imagine that you include a plugin, plugin steps and activate them in a solution. Later solution was exported as Managed Solution to another environment. In this scenario, the supplied Secure configuration information would NOT be available in the new environment. The simple reason behind this is to provide more security to the contents of Secure Configuration.
Consider a scenario that you have developed a plugin and certain parameter strings are designed to supply to the plugin in such a way that it is required to run the plugin smoothly.If you supply these parameter strings under secure configuration then the plugin will work fine only for the CRM Administrators. The simple reason is secure configuration can only be read by a CRM Administrator. So if the user is not a CRM administrator then the plugin would try to read but it would fail just because its under the secure configuration.All public information should be supplied via Unsecure configuration section. So please remember these tips when you supply the secure and unsecure configuration via Plugin Registration tool.