• It is recommended that you encrypt the data in order to keep the communication secure whentransferring configuration files.However, if you are using the units within a secure environment, such as within an intranet, it is notnecessary to encrypt the data.To decrypt configuration files, the unit uses the encryption key registered to it beforehand. The unitdetermines the encryption status by checking the extension of the downloaded configuration file.For details about encrypting configuration files, contact the appropriate person in your organization.Extension of ConfigurationFile Configuration File Parameters Used for Decrypting".e2c" CFG_FILE_KEY2".e3c" CFG_FILE_KEY3Other than ".e2c", and ".e3c" Processed as unencrypted configuration files.The extension ".cfg" should be used for unencrypted configuration files.Comparison of the 2 MethodsThe following table compares the characteristics for the 2 transfer methods.Transferring EncryptedConfiguration FilesTransferring Configuration FilesUsing HTTPSProvisioning server load Light Heavy(The server encrypts data for eachtransmission.)Operation load Necessary to encrypt databeforehand.Unnecessary to encrypt databeforehand.Management ofconfiguration filesFiles must be decrypted and re-encrypted for maintenance.It is easy to manage files becausethey are not encrypted on the server.Security of data on theserver when operatingHigh Low(Configuration files are readable byanyone with access to the server.)Moreover, there is another method: configuration files are not encrypted while stored on the server, andthen, using the encryption key registered to the unit beforehand, they are encrypted when they aretransferred. This method is particularly useful when several units are configured to download a commonconfiguration file using different encryption keys. However, as when downloading an unencryptedconfiguration file using HTTPS, the server will be heavily burdened when transferring configuration files.2.3 Priority of Setting MethodsThe same settings can be configured by different configuration methods: provisioning, Web user interfaceprogramming, etc. This section explains which value is applied when the same setting is specified bymultiple methods.The following table shows the priority with which settings from each method are applied (lower numbersindicate higher priority):Priority Setting Method3 The factory default settings for the unit2 Pre-provisioning with the configuration file2.3 Priority of Setting Methods38 Administrator Guide Document Version 2016-05
