Hi Frieda,
With regards to security of form information:
On Mobile Devices: Survey123 currently does not do any encryption of it's own and relies on the encryption supplied by the phone. In general, modern iOS (version 3+) and Android (version 6+) phones encrypt the file systems (all files) of the device when 'at rest', i.e. when powered off. We have an enhancement request to support encryption, but it has not yet appeared as a high user priority.
On Server Storage: Survey123 data can be sent to either an ArcGIS Online organization or ArcGIS Enterprise (on premises) implementation. For additional security information about both, please refer to http://trust.arcgis.com
- ArcGIS Online: Data access control is secured via ArcGIS online's authentication. Data is not encrypted at rest.
- ArcGIS Enterprise: Hosted Feature Services (default table) do not encrypt data at rest; Survey123 can, via a ArcGIS Server Service, write to an enterprise database, whose encryption status is controlled by the System Administrator and Database Administrator.
In addition to your questions of on device and on server, let me also address data in transit (from mobile application to server) - if the destination server supports SSL, the data transmission is encrypted and sent via SSL.
Survey123 is available as a template in AppStudio; a custom version can be modified to support encryption of the data or to delete a survey once successfully submitted.
