使用bouncy castle 的jar包实现的ElGamal加密模块，以及测试用例，需要导入bouncy castle包（内附），并且你需要在JDK的JRE环境中，或者是JRE环境中配置上local_policy.jar和US_export_policy.jar（压缩包内已有jdk6和7的）。

切换到 JDK_Home \jre\lib\security目录下，对应覆盖local_policy.jar和US_export_policy.jar两个文件。同时，你可能有必要在 JRE_Home \lib\security目录下，也需要对应覆盖这两个文件。

配置权限文件的最终目的是为了使应用在运行环境中获得相应的权限，可以加强应用的安全性。

通常，我们在应用服务器上安装的是JRE，而不是JDK。因此，这就很有必要在应用服务器的 JRE_Home \lib\security目录下，对应覆盖这两个权限文件。-Use bouncy castle jar package implements the ElGamal encryption module, as well as the test case, you need to import a bouncy castle pack (included), and you need the JDK JRE environment, or the JRE the configuration on local_policy.jar and US_export_policy.jar (compression packages of existing jdk6 and 7). Switch to　JDK_Home　\ jre \ lib \ security directory, the corresponding coverage local_policy.jar, and US_export_policy.jar two files. At the same time, you may need in the　JRE_Home　\ lib \ security directory also needs corresponding to the coverage of these two documents. Configuration permissions files ultimate goal is to make application to obtain the appropriate permissions in the operating environment, can strengthen the security of the application. Typically, it is installed on the application server JRE, instead of JDK. This is necessary in the application server　JRE_Home　\ lib \ security directory corresponding to the coverage of these two permissions file.