NCHAIN LICENSING AG

A computer-implemented method of generating a share of a digital signature of a message, wherein a threshold number of different signature shares from respective participants of a group of participants are required to generate the digital signature, wherein each participant has a respective private key share, the method being performed by a first one of the participants and comprising: generating a first message-independent component and a first message-dependent component, wherein the message-independent component is generated based on a first private key share and wherein the message-dependent component is generated based on the message; causing the first message-independent component to be made available to a coordinator; and causing a first signature share to be made available to the coordinator for generating the signature based on at least the threshold number of signature shares, wherein the first signature share comprises at least the message-dependent component.

A server of media content makes a first transaction available to users that includes a first output specifying an amount of a digital asset to transfer to a second party, and a total of zero or more inputs wherein a total input amount of the digital asset specified in any outputs of any source transactions pointed to by the zero or more inputs is less than a total output amount of the digital asset specified by the one or more outputs. Inputs are received from users of a side channel. Once a target is reached, the first transaction and a second transaction are recorded in a blockchain, wherein the second transaction comprises an input pointing to the first output of the first transaction and an unlocking script meeting a condition that requires the unlocking script to include a media key enabling the users to access the item of media content.

The present disclosure provides a method of implementing a payment service for one or more clients for transactions associated with a distributed ledger, such as the Bitcoin blockchain. The method comprises providing an alias for a client, associating the alias with a network in a directory and providing a location for a host computing resource responsible for the payment service, wherein the host computing resource is configured to facilitate identification of the client associated with the alias. The present disclosure also provides a method comprising creating a machine readable resource in a location associated with the payment service, wherein the machine readable resource comprises an endpoint identifier for the payment service, an entry associated with at least one capability supported by the payment service, and instructions and/or a specification for accessing a public address for facilitating transactions associated with the alias. The present disclosure also discusses a method of implementing a simplified payment protocol for clients associated with the payment service.

A method of providing proof that a statement is true keeping a secret input to the statement a secret, comprising: generating a proof using a public input, the secret input, and a proving key linked to an augmented verification circuit which comprises (i) a verification circuit arranged to receive the inputs, supply the secret input to a function circuit representing the statement to generate a function circuit output, and determine whether the public input corresponds to the function circuit output; and (ii) a multiplicative gate arranged to receive the secret input and a dummy value. The proof comprises a commitment to inputs of multiplicative gates of the augmented verification circuit, the commitment generated using a first vector comprising n components from a finite group of data elements. The secret input is a discrete logarithm of a public element of said finite group. The proof is transmitted to a verifying device.

A computer-implemented method for generating a zero-knowledge proof for proving each data block of a plurality of data blocks corresponding to a Merkle tree satisfies a predefined criterion. Leaf nodes are mapped to leaf hash values of the Merkle tree and inner nodes are mapped to inner hash values of the Merkle tree. The leaf nodes are executed, with each leaf node: receiving a respective data block and a corresponding data block proof for proving the data block satisfies the predefined criterion; verifying the respective data block proof; computing and outputting a data block hash. The inner nodes are executed, with each inner node: receiving, from each of two previous nodes, a respective hash value; computing and outputting an output hash value. The output hash value computed by a final inner node in a final layer of the Merkle tree is a Merkle root corresponding to the Merkle tree.

The present disclosure proposes methods, devices, systems, and computer programs for creating a permit. In more details, the method comprising the steps of receiving a request comprising a first permit identifier, wherein the first permit identifier identifies a first permit, and obtaining a first permit data based on the first permit identifier wherein the first permit data comprises data indicative of at least one permission and wherein the at least one permission provides an indication of one or more actions a holder of the first permit can take and/or what the holder of the first permit is allowed to do, wherein the request is a request to create a further permit and the request comprises data indicative of a further permit.

A computer implemented method of using a blockchain to coordinate data transfer over a P2P network. The method comprises obtaining a second hash value, wherein the second hash value is generated by hashing at least a data request with a first hash function to generate a first hash value and then hashing at least the first hash value with a second hash function to obtain the second hash value. The data request is associated with the target data item. A primary request transaction is submitted to a blockchain network, wherein the primary request transaction comprises the second hash value and one or more first outputs, each first output being locked to a respective public key associated with a respective P2P node connected to the requesting P2P node. The target data item is obtained from the target P2P node.

The invention provides a secure method for exchanging entities via a blockchain. The invention incorporates tokenisation techniques, and also techniques for embedding metadata in a redeem script of a blockchain transaction. Embodiment(s) provide a computer implemented method of performing a transfer, the method comprising: generating a first exchange transaction, and broadcasting, over a first network, the first exchange transaction for inclusion on a P2P distributed ledger, wherein the first exchange transaction comprises: an indication of a first quantity of a cryptocurrency to be transferred; a first input provided from an output of a first invitation transaction from a first user, the first invitation transaction previously included on the P2P distributed ledger, a first script, a first user private key associated with the first user, a first third-party private key associated with a first third-party, and a first output indicating a transfer of a first entity from the first user to a second user; and wherein the first script comprises: a first set of metadata providing an indication of the first entity to be transferred and a first set of conditions for the transfer, a first user public key associated with the first user, the first user public key being a cryptographic pair with the first user private key, and a first third-party public key associated with the first third-party, the first third-party public key being a cryptographic pair with the first third-party private key.

A method of generating a blockchain transaction comprising: generating a transaction comprising a locking script comprising a first shared hash value (HV) generated by applying a hash function (HF) to a second shared HV, wherein the second shared HV is generated by applying a HF to a combination of the respective public keys, and wherein the locking script is configured to require an unlocking script to comprise a target public key, a target signature, and an intermediate HV generated based on all but one of the respective public keys, apply the HF to the target public key to generate a target HV, combine the target HV and the intermediate HV to generate a target second shared HV, apply the HF to the target second shared HV to generate a target first shared HV, an verify that the target first HV matches the first shared HV, and verify the target signature.

A computer-implemented method of using a multi-level (ML) data chain protocol to embed a data chain on a core blockchain, comprising: obtaining one or more ML transactions, wherein each ML transaction comprises one or more carrier pairs, each carrier pair comprising an input and an output, wherein each output comprises data associated with the data chain, and wherein each input comprises a signature that signs the carrier pair; generating a first ML block of the ML data chain, wherein the first ML block is a core blockchain transaction and comprises the respective carrier pairs of the obtained one or more ML transactions, wherein for each carrier pair, a respective position index of the respective input corresponds to a respective position index of the respective output, and a first chain output that is for being spent by a respective chain input of a subsequent ML block.