WordPress.org

This plugin has two main features:

• any reader on your website can comment if one has an Instant Messaging address (XMPP protocol, otherwise called Jabber. A Gmail or a LiveJournal account for instance are such standard IM identifiers as well);
• a subscribed user (whatever its role) can authenticate with one's IM address if they set their IM address.

This plugin is still in experimental state but is usable.

Detailed Process

The authentication part is something like openID, except that it uses your existing IM address: you ask for authentication on a website, and it pops-up a confirmation via IM (that you can accept, or refuse).

Considering that the IM protocol (XMPP) is very secure, all the infrastructure to securely exchange an authentication request is there. No need to make any new account, no need a special client, nor a identity third party provider, and that's really instantaneous (as instant messaging) and more secure than HTTP or SMTP protocols.

Spam Protection

It adds an additional layer to protect against Spam by verifying an identity using a very secure and modern protocol (XMPP), which also is instant, hence much more reliable in any way than email for instance.

Secure and Easy Login

Many reasons to use such a plugin for login:

• not to have to remember a new password (password-login can be disabled in your profile, on a per-user choice);
• you are in a very insecure environment (for instance a cybercafe) and consider only your IM account to be a minimum securized. Or better, you run an IM client on your smartphone (or a similar tool), so you would receive the query on this personal item while never typing any kind of password on the insecure platform where you log.
• And so on.