<machineKey validationKey="<SOME_VALUE>" decryptionKey="<SOME_VALUE>" validation="SHA1" decryption="AES"/>

var machineConfigMachineKey = (MachineKeySection)WebConfigurationManager.OpenMachineConfiguration().SectionGroups["system.web"].Sections["machineKey"];
var webConfigMachineKey = (MachineKeySection)WebConfigurationManager.OpenWebConfiguration("").SectionGroups["system.web"].Sections["machineKey"];
Response.Write("<pre>");
Response.Write("<b>machine.config decrypt:  </b>" + machineConfigMachineKey.DecryptionKey + "<br />");
Response.Write("<b>web.config decrypt:      </b>" + webConfigMachineKey.DecryptionKey + "<br />");
Response.Write("<br />");
Response.Write("<b>machine.config validate: </b>" + machineConfigMachineKey.ValidationKey + "<br />");
Response.Write("<b>web.config validate:     </b>" + webConfigMachineKey.ValidationKey + "<br />");
Response.Write("</pre>");
Response.End();

machine.config decrypt:  AutoGenerate,IsolateApps
web.config decrypt:      AutoGenerate,IsolateApps

machine.config validate: AutoGenerate,IsolateApps
web.config validate:     AutoGenerate,IsolateApps