US Patent 10298395 Interoperability of zero-knowledge proof enabled blockchains

For shielded cryptographic data exchange interoperation, an interoperability node is in communication with a furnisher participant node of a furnisher distributed ledger technology (DLT) network and a receiver participant node of a receiver DLT network. The interoperability node may obtain a shielded exchange instruction. The shielded exchange instruction may include a zero-knowledge proof, a selected token nullifier, a new token nullifier, and a new token digest. The zero-knowledge proof may be indicative of the furnisher participant having access to the selected token identifier. When the interoperability node determines that the new token nullifier is not present on a receiver blockchain, the interoperability node may submit the shielded exchange instruction to a furnisher smart contract and a receiver smart contract. The furnisher smart contract may retire the selected token nullifier on the furnisher blockchain. The receiver smart contract may insert the new token nullifier and the new token digest to the receiver blockchain.