Plugin has mechanism to dynamically install extensions for applet.
However, for this mechanism to work, the extension has to have at least some VERSION information and also provide installer if more sophiscated installation is needed. Currently, JSSE is distributed with JDK. However, due to import restriction imposed by different countries, only the weak-crypto version of JSSE is included in JDK. For applets which require strong crypto, plugin need to download strong crypto JSSE at runtime.
In order for plugin to retrieve strong crypto JSSE, JSSE needs to provide its own installer for this purpose as well as provide version info for Plugin.