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.

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.

A method of enforcing a locking script to be propagated throughout a chain of blockchain transactions. The method comprises generating a primary transaction comprising a primary locking script configured to, when executed by an unlocking script of an auxiliary transaction, verify that the unlocking script comprises a message generated based on the auxiliary transaction, and verify, based on the message, that an output of the auxiliary transaction comprises an auxiliary locking script. The auxiliary locking script is configured to verify that an unlocking script of a second primary transaction comprises a message generated based on the second primary transaction, verify that the unlocking script of the second primary transaction comprises a data item comprising one or more locking scripts of the primary transaction, and verify, based on the message and the data item, that an output of the second primary transaction comprises the primary locking script.

A computer-implemented method of generating a respective signature share of a digital signature for signing a message, wherein the method is performed by a first participant of the group and comprises: obtaining at least the threshold number of respective participant indexes, wherein the obtained respective participant indexes comprises a first participant index associated with the first participant; generating a private key index, wherein the private key index is generated based on a hash of a combination of the obtained respective participant indexes; generating a second common private key of the first hierarchical key structure; and generating a first signature share of the digital signature.

A solution for controlling access to a resource such as a digital wallet implemented using a blockchain. Use of the invention during set-up of the wallet can enable subsequent operations to be handled in a secure manner over an insecure channel. An example method comprises splitting a verification element into multiple shares; determining a common secret at multiple nodes in a network; and using the common secret to transmit a share of the verification element between nodes. The shares can be split such that no share is sufficient to determine the verification element and can be stored at separate locations. Upon share unavailability, the share can be retrieved a location accessibility. For safe transmission of the share(s), the common secret is generated at two different nodes independently and used to generate an encryption key for encrypting at least one share of the verification element to be transmitted securely.

Techniques are presented relating to steps after a congress pool has accepted a request from a requester to activate a script. The steps include preparing, by a node, a blockchain transaction cryptographically locked with a public key associated with the congress pool, the blockchain transaction configured to permit a plurality of information providing systems to add inputs to the blockchain transaction; determining a centre point for data received from the plurality of information providing systems; and activating, by the node in cooperation with other nodes of the congress pool, the script based on the centre point.

Systems and methods described herein relate to techniques in which multiple parties each generate and exchange quantities that are based on a shared secret (e.g., powers of the shared secret) without exposing the shared secret. According to a protocol, two or more parties may exchange sets of elliptic curve points generated over polynomials that can be used, by each of the two or more parties, to determine a power of a shared secret. The protocol may be utilized as part of determining parameters for a smart contract that is broadcast to a blockchain network (e.g., Bitcoin). Based on the protocol, an additional party (e.g., a third party different from the two or more parties) may perform a computational task such as execution of the smart contract.

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 computer-implemented method of generating shares of a shared secret, wherein each of a group of participants has a respective first secret share of the shared secret, wherein the method is performed by a first participant of the group and comprises: generating a respective blinding share of a shared blinding secret, obtaining at least a threshold number of respective intermediary shares from each of the first group of participants, wherein each respective intermediary share is generated based on a respective blinding share and a respective first secret share; generating an intermediary value based on each of the obtained intermediary shares; and generating a respective second secret share of the shared secret, wherein the respective second secret shared is generated based on the intermediary value and the respective blinding share.