The CryptoTag™, a novel IoT device, has been designed, prototyped, and field-tested. It operates from renewable energy sources, and is capable of provisioning itself and securely operating with no use of externally provided security certificates and with minimal human supervision. It was designed for a first application in today’s electrical grid, which is, at best, implemented with security as an afterthought. Today’s systems cannot be easily modified to implement security—security must begin with chip-level identity in the network’s leaf nodes. Our CryptoTag creates and autonomously authenticates its unique identity and also creates and manages any secrets necessary for secure communication. The CryptoTag, which can be incrementally introduced compatibly with today’s systems, works with a complementary secure communications protocol to ensure transaction security. The first versions of a CryptoTag-based system monitor the electrical grid. The current pipeline of systems in design will result in an integrated CryptoTag suitable for fielding in a wide range of vertical market segments.