Idea of Lock Icon
The image is the basic rounded outline of a padlock. The padlock has a U-shaped part sticking out the top where you would loop it through the thing your are locking. Currently it is in the locked position. In the middle of the main, round, body of the lock is a keyhole where the pins of the key would go in pointing down.
This Lock icon has Android KitKat style
. If you use the icons for Android apps, we recommend using our latest Material Icons icon pack (please check our sidebar on the right). Otherwise, it's a solid icon pack that looks good in small resolutions, either on the web or in print. It's characterized by thick lines, smooth corners, and is optimized for 24x24 pixels.