Should I use Google Accounts or my own hashed password system?

Question

I have a relatively critical control-panel online. If someone with malicious intent were to log in, there would be a significant risk to property. I will be hosting said site on Google App Engine, everything will be through SSL, and have a proper password system with random hashes.

Now, looking through app-engine questions on SO.SE, I found this answer that indicates that it would be best not to deal with passwords at all, and instead use Google Accounts login.

What are the pros and cons of using Google accounts v. managing my own password database?

Answer 1

Google offers 2 factor authentication, but because the account can be used for many sites there can be more likelihood of someone gaining access to an already authenticated client. As you are trusting google anyway (with Google App Engine) its not much more attack surface to have them manage authentication as well. Hosting on your own server with 2 factor authentication and Public keys would be the most secure option if you have the time and know how.