Answer by Jay Allen for ssh password authentication: use a graphical prompt?

In lieu of the information I mentioned in my comment above, here are some other possibilities:

• You can set the GIT_ASKPASS environment variable (either in your shell or, better, when launching your git client) to the path of a helper app which will pop up a graphical password dialog (e.g. ssh-askpass, ksshaskpass, gnome-askpass, ssh-askpass for Mac, Cocoa dialog, etc)
• You can use the gitcredentials feature to store your password temporarily in memory, in a private but unencrypted file on the filesystem or—using a platform-specific, third-party helper such as KDEWallet, GNOME Keyring, Mac OS X keychain or Windows Credential Store.
• Or, you can use an encrypted .netrc file

I haven't done the latter but apparently that sounds like the most secure way to go about it, assuming you're running the requisite Git version.