https://www.linode.com/docs/security/use-public-key-authentication-with-ssh

1.使用ssh-keygen產生
2.家目錄底下的.ssh權限為600 , authorized_keys權限為700
3.拷貝id_rsa.pub內文至authorized_keys
4.利用puttygen對id_rsa產生.ppk的金鑰
5.將金鑰套用在putty與winscp上

附加一篇：增加Server的安全性
https://www.linode.com/docs/security/securing-your-server