Whether the file transfer is a homework assignment, a submission, or a document moving repeatedly among a group of collaborators, file security is important, and probably the last thing on a teacher's mind.
Miguel Guhlin at TCEA has jumped into the fray, and prepared a great article addressing file security and the G suite, especially for Chromebook users. It's good reading, as it focuses on free and open source software that allows people to encrypt their emails and documents from sender to receiver.
Here are some solutions. They are web-based, except as noted:
- Paranoia Text Encryption Tool, or PTE
- Secret Space Encrypter (Android app)
- Fourmilab's Browser Tool
You may read the article here.