Please refer to following URL.
The Best Free Encryption Software for 2020 [Complete Guide]
https://medium.com/@stewofkc/the-best-free-encryption-software-for-2019-complete-guide-4ba986fd3fb0
Full Disk Encryption
File Encryption Software
1. Encrypto
https://sourceforge.net/projects/encrypt/
2. Cryptomator
https://cryptomator.org/
3. Boxcryptor
https://www.boxcryptor.com/en/
4. AES Crypt
https://www.aescrypt.com/
5. EncFS
https://github.com/vgough/encfs
6. AxCrypt
https://www.axcrypt.net/
Encrypted Internet Traffic
Email Encryption
Encrypted Messaging Systems
Other Encryption Tools