Every time you synchronize or upload code to the code base on githun, you need to enter your username and password every time. In this case, we can save these by setting an SSH key. Trouble. If you use TortoiseGit as the local github management tool, TortoiseGit uses the secret key with the extension ppk instead of the rsa key generated by ssh-keygen. In other words, the key generated by using ssh-keygen -C "username@email.com" -t rsa cannot be used in TortoiseGit. Development based on github must use rsa keys, so TortoiseGit's putty key generator tool needs to be used to generate both rsa keys suitable for github and ppk keys suitable for TortoiseGit.