Blockchains (smart contracts, distributed ledgers) and rights management broadly construed are the themes of today's Spotlight Patents. Assigned to ITRI (TW), the first patent addresses techniques for digital rights management system and digital rights protection. Assigned to Blockstream, the second patent addresses techniques for cryptographically concealing amounts and asset types for independently verifiable transactions.
11,080,368, "Digital rights management system and digital rights protection method," assigned to Industrial Technology Research Institute (TW)
A digital rights management system and a digital rights management method are provided. The digital rights management system includes an authority management module, a user confirmation module and an authority blockchain. The authority management module is configured for: receiving a user authority information corresponding to a user end from a service providing; sending user authority information to the user confirmation module; receiving an identification code corresponding to the user authority information from the user confirmation module; and sending and storing the user authority information and the identification code into the authority blockchain. Therefore, the authority management module, the user confirmation module and the authority blockchain manage and protect digital rights.
11,080,665, "Cryptographically concealing amounts and asset types for independently verifiable transactions," assigned to Blockstream Corporation (CA)
Systems and methods are described for encrypting amounts and asset types of a verifiable transaction on a blockchain ledger. For each asset, an asset tag is blinded, multiplied by the amount of the asset, and the product is blinded again to create an encrypted amount of the asset. Both encrypted amount of the asset and a corresponding generated output value are within a value range, and the sum of the encrypted input value and the encrypted output value equals zero. Rangeproofs for each of the encrypted output values are associated with a different public key. Each public key is signed with a ring signature based on a public key of a recipient. A second ring signature is used to verify each asset tag, where the private key of the second ring signature for each asset is a difference between a first blinding value and an output coefficient.