A locked padlock with a keyhole or a security icon.

Padlock

Security Icon

A locked padlock or a security icon inside a circle.

A padlock inside a circle, representing a security icon. 

A line chart below a security shield icon.

A locked padlock or a security icon and a pointy decorative star.

A security icon with a keyhole icon inside a hexagon within another hexagon made from lines connected by circles or dots.

A security icon featuring a shield outline with a check mark in the center.