Personalized Graphics for Password Fields

Referring to a paper describing a scheme for using 'dynamic security skins' as a defense against phishing attacks, Ben Hyde writes "This is a perfect opportunity for a grease monkey script!"

The following simple script demonstrates the principle of using user-specific graphics to simplify server authentication (while in no way implementing the full system outlined in the paper Ben references).

For trusted sites (mock ones listed below under '@include'), a user-chosen graphic (here my Flikr logo), is used as the background image for the password field. The effect is shown in the graphic above, it's a capture of the password interface for one of my trusted sites with a visual cue to that effect (the alternating purple-bands are an artifact of the dimensions of my logo).

//
// ==UserScript==
// @name Personalized Password Fields
// @description Displays user-chosen graphic in trusted password fields
// @include https://*.bank-a.com/*
// @include https://*.bank-b.com/*
// ==/UserScript==

function addStyle(css) {
var head, style;
head = document.getElementsByTagName('head')[0];
if (!head) { return; }
style = document.createElement('style');
style.type = 'text/css';
style.innerHTML = css;
head.appendChild(style);
}

var backg = "input[type='password'] { background: url(http://photos6.flickr.com/buddyicons/25436942@N00.jpg?1110378496) }";

addStyle(backg);