You can use this property with the WebBrowser.EncryptionLevelChanged event to implement an indicator in the user interface of your application similar to the lock icon in Internet Explorer. When the current document is not encrypted, the value of this property is WebBrowserEncryptionLevel.Insecure. When the System.Windows.Forms.WebBrowser control displays a Web page containing multiple frames with content of different encryption levels, the value of this property is WebBrowserEncryptionLevel.Mixed. When the encryption level is unknown, the value of this property is WebBrowserEncryptionLevel.Unknown. Other values indicate the type of encryption present. To mimic the behavior of the lock icon in Internet Explorer, display the encryption type in a ToolTip that appears when the mouse pointer hovers over the indicator.