If you are sharing passwords or other sensitive data over IM, email etc. you should take a look at this free web application. The application is called cryptgeon and is developed by a guy called Nicco. The application will only keep the shared secrets/files in memory and not write the data to disk. You can have a look at his GitHub repo here or see the screenshot below for the UI.
If you are using docker engine and docker-compose here’s the compose file I’m using to run the application.
version: '3.7' services: memcached: image: memcached:1-alpine entrypoint: memcached -m 128M -I 4M # Limit to 128 MB Ram, 4M per entry, customize at free will. app: image: cupcakearmy/cryptgeon:latest depends_on: - memcached environment: SIZE_LIMIT: 4M ports: - 82:5000 restart: unless-stopped