Your unencrypted text is sent to the digitalocean letsencrypt secured server over https. That text is then scrambled using
standard open source encryption algorithms, in memory. The result is then passed back in the https REST response and
presented on this web page. Your raw text is not copied and stored anywhere.
If you don't know me, then it is not best practices to trust the prior statement, so a safer thing for you to do
would be to download the application, and run it on your PC. The absolute safest thing to do would be to build the application
from source, so you could verify that your unencrypted text is not stored anywhere.