Systems and methods build blockchains and verify assets for smart contracts. A system includes a memory, a blockchain, a set of nodes, a set of verifiers, a set of miners, and a consensus protocol. The memory can have a block data structure representing a transaction for an asset having an identifier and at least one verifiable characteristic. The consensus protocol can include rules for: receiving the stake at risk from the verifiers, providing the reputational score to the verifiers, verifying the verifiable characteristic of the asset by the verifiers, cryptographic verification by the miners, adding the new block to the blockchain by the miners, providing the reward to the miners, and distributing the copy of the blockchain to each node.