Blockchain enthusiasts and evangelists have often stated that supply chain management, identity, and payments would be some of the biggest use cases in blockchain. But smart contracts are currently unable to get trusted data from the physical world, and must rely on fragile oracles and web APIs. Blocktag has the physical technology that can make this secure link. Although Blocktag was started in mid 2018, it utilizes nano optical tech that some of the cofounders invented – proven physically secure over decades, and now with the additional data security of blockchain.