2022
https://habr.com/ru/post/659905/
2021
https://itsfoss.com/gpg-encrypt-files-basic/
2016
https://www.fpcomplete.com/blog/2016/05/stack-security-gnupg-keys
https://help.riseup.net/en/security/message-security/openpgp/best-practices
2013
https://chrisjjohnson.wordpress.com/2013/07/01/approaching-openpgp/