PNG ICO ICNS MORE
Network & communications
Smooth
Oxygen
Lock, Unlock, password
LightGray
48x48
UI
Function icons
Lock, Unlock, open
WhiteSmoke
Shopping & e-commerce
Siena
Blue, Unlock
Black
256x256
Unlock, green
Unlock, red
Unlock, security
Desktop apps
KDE Crystal Diamond
Unlock
22x22
Mixed
Vista Inspirate
Silver
32x32