Have you ever wondered how file sharing in Wickr works?
When a users receives a file, If they select 'Open', the file is decrypted into a temporary file which is stored within the app directory and opened in the appropriate application.
Our app cleans these temp files up regularly by constantly scanning that directory and deleting files there. After that, our anti-forensic routines work to clean up the deleted data.
On the other hand when a user receives a file and they select 'Export/Save' they are decrypting the file out of the Wickr container and storing it in plaintext on their device.
There are options to consider should you have concerns where/how files are shared & stored. These include:
1. A customer "use policy" that requires transfer of 'already encrypted' files (so that they are still encrypted after export) or
2. Device-based encryption to ensure that everything stored on the device (even after export from Wickr) is encrypted at rest - in essence implementing a second layer of data-at-rest file encryption.
3. We are also considering a read-only file transfer option for PDFs only that have no export function and are opened completely in memory. This is something we would consider adding it to our roadmap based on high customer demand.
Please email us at firstname.lastname@example.org if you have any questions on file sharing.