An organization has a system in AWS that allows a large number of remote workers to submit data files. File sizes vary from a few kilobytes to several megabytes...

An organization has a system in AWS that allows a large number of remote workers to submit data files. File sizes vary from a few kilobytes to several megabytes.
A recent audit highlighted a concern that data files are not encrypted while in transit over untrusted networks.
Which solution would remediate the audit finding while minimizing the effort required?