olemus
automaatne krüpteerimine
salvestisse (kettale, mälupulgale) kirjutamisel ja
automaatne dekrüpteerimine sealt lugemisel

täpsemalt
https://study.com/academy/lesson/what-is-on-the-fly-encryption.html

https://www.east-tec.com/kb/what-does-on-the-fly-encryption-mean/

vahendinäiteid
https://www.secureaction.com/products/onthefly/

https://www.ubuntupit.com/top-20-best-disk-and-file-encryption-software-for-linux/

https://www.slant.co/topics/1444/~best-file-encryption-tools