Original sources for the padlock icons were
Wikimedia commons: http://commons.wikimedia.org/wiki/Category:Padlock_icons

Specifically, the Bronze padlock at
http://commons.wikimedia.org/wiki/File:Padlock.svg
by AJ Ashton at https://openclipart.org/detail/17931

And the Gold padlock at
http://commons.wikimedia.org/wiki/File:Padlock-gold.svg
which is the above padlock recolored by AzaToth.

My mods are in the attached Inkscape SVG file.
End-result PNGs had some tweaks. Biggest is applying a filter to the locks before export:
Filters->Shadows and Glows->Darken edges.

All of these icons are released to the Public Domain.

-Todd Stedl
01 October 2014.
