关于加密算法的分类
http://www.ruanyifeng.com/blog/2006/12/notes_on_cryptography.html
公钥、私钥、签名、证书
https://cloud.tencent.com/developer/news/276498
数字签名是什么？
http://www.ruanyifeng.com/blog/2011/08/what_is_a_digital_signature.html
利用 GPG 签名验证文件的完整及可靠性
https://blog.chaos.run/dreams/gpg-verify
使用 GnuPG 加密签名来验证下载文件的可靠性和完整性
https://linux.cn/article-4378-1.html
GnuPG的使用入门
https://www.cnblogs.com/buchiany/p/6665637.html
How to verify the authenticity and integrity of a downloaded file on Linux
http://xmodulo.com/verify-authenticity-integrity-downloaded-file.html
用 OpenPGP/GnuPG 对邮件签名和加密
https://www.jianshu.com/p/d9f6ddbcfa3f
GnuPG 的三个使用场景
https://www.jianshu.com/p/b6261fd143fc
GPG入门教程
http://www.ruanyifeng.com/blog/2013/07/gpg.html
GPG：从您的公共密钥环中删除密钥？
http://www.yeslib.com/detail/3584
国内可访问GPG Keyserver列表
http://blog.chinaunix.net/uid-20420254-id-2890214.html
利用Gpg4win来打造一个安全的加密文件
https://blog.51cto.com/z00w00/2070169
Gpg4win - a secure solution
https://www.gpg4win.org
Check integrity of Gpg4win packages
https://www.gpg4win.org/package-integrity.html
https://wiki.gnupg.org/Gpg4win/CheckIntegrity
