Guardian Keyhole

Prompt

Design an icon representing a "Guardian Keyhole," symbolizing access control and security. The icon should feature a stylized keyhole at the center surrounded by a protective circular outline, resembling a guardian's shield. The keyhole itself should have a modern and smooth design with a slight shadow to add depth, while the outer shield-like form should have clean, balanced lines to reinforce the concept of safety. Use a color palette of deep indigo and slate gray, conveying a sense of trust and authority, with subtle gradients for depth. The overall aesthetic should be minimal and easily recognizable, making it ideal for use in UI icons, app icons, or logos related to security and access management.