Firefox has made a really cool tool to send files over the internet encrypted.
Simply go to https://send.firefox.com/ and try it out.
You can send a file up to 1GB without signing up. If you signup you get more options and can send a file as large as 2.5GB. Pretty neat if you ask me.
You can set a limit to how many times the file can be downloaded before it is deleted from the servers: one, two, three, four, five, 20, 50, or 100 times. You can also set a time limit before deletion—seven days, one day, one hour, or five minutes. Finally, you can set a password of your choice for access to the file. After you go through this brief process, you'll get a link to send to the recipient to download the file.