PNG ICO ICNS MORE
Computer & hardware
Pixel
ASP.NET icons
Lock, password, secure
SaddleBrown
16x16
UI
Smooth
Function icons
48, Lock
Gainsboro
48x48
Lock, Unlock, open
WhiteSmoke
Shopping & e-commerce
Siena
green, Lock
Black
256x256
Lock
Lock, red
yellow, Lock
Mixed
DRF
security, safety, secure
32x32
Fugue Icons
DarkGoldenrod
Arrow, Lock
Lock, Minus
Lock, exclamation
pencil, Lock
Lock, plus
Lock, disable
DarkGray
Unlock, Lock
Carpelinx
password, secure, Lock
128x128
File, Lock
64x64
Desktop apps
KDE Crystal Diamond
File, locked, secure
Snow
22x22