We need an icon to represent our new product Smartcrypt. The icon and various iterations will be used in Mac menu bar and Windows system tray, as well on the App Store and Google Play, and therefore on mobile devices.
Our product imagery is typically key-based because that's the industry standard and is pretty immediately recognizable. While we're open to riffs on the key idea, we're also excited about the prospect of reviewing designs that take a different approach to client-side encryption.
There's very little required, other than metaphors that are recognizable and accepted by the industry. We typically go for defensive weaponry as metaphor for protection, rather than offensive. Shields rather than swords, etc.
That said, our product armors data whether it's at rest or in motion. That's a key difference from other products, which build walls and protect the data before hackers get to it. Because ours is protected/encrypted/armored, it doesn't matter whether someone gets past the wall - they'll still only be stealing useless information without the ability to unlock the data, which they won't have. So, the shield/wall/vault metaphor still isn't exactly correct.