Email users rarely use end-to-end encryption. It takes effort and requires explicit action. Users may not see the need for this, have access to the technology, possess the know-how, or may be faced with complex interfaces. To enable effortless exchange of encrypted emails we propose KeyRing, a design for a wearable device that builds on in-person trust establishment through device pairing. This pairing can be used to make the exchange of secure emails between the wearers easier. We discuss how the corresponding interactions of handshake, seal, and unseal can be implemented, and find that the most promising approaches are a ring communicating over infrared and a wristband communicating over Bluetooth. Issues around the human-device interface, user acceptance, feasibility, and deployment are discussed, but need further work.