Back to Secure website-authentication using GPG keys
> One of the bigger problem with this I can foresee is userA > putting userB's public key in their own account - this would > lead to duplicate keys. Although this would effectively lock > userA from his own account, allowing userB to possibly log in > as him.
The problem is that it might be overly technical for most users, so having it as an option for login could be nicer. (and having it in an option somewhere to enable, so as not to scare off illiterate users).
Another thing that could be done is bringing authentication to the client side would be to run a javascript hash on the clientside. (creating an authentication token using hashes of both username, password and a nonce sent through a hidden form value.).
This would be simple enough. Clear the password in javascript, set a new hidden field with the digest value and then on the server side use the digest to authenticate. You then know who they authenticate as using the provided username.
Talk about implementation of a poc?