use QR code to login to website
<p>I am thinking of using a QR code to login to a website. This way a user doesn't have to enter a user id/password.</p>

<ol>
<li>users goes to a website.</li>
<li>the website need autorisation.</li>
<li>the website present a QR code.</li>
<li>the user scans the QR code with his/her phone.</li>
</ol>

<p>Somehow the originating website gets confirmation that the QR code was scanned by a known phone.</p>

<p>Now the website knows the user and the user is logged in.
This is safe because the phone is known to the site.
If needed the user can protect the phone with a PIN code or other locking system.</p>

<p>Does anybody know if somebody has already build such a system?
Some code would be nice :-)</p>
