Nchain Licensing Ag

Nchain Holdings Limited

Pauline Bernat

Silvia Bartolucci

Daniel Joseph

Craig Steven Wright

A computer-implemented method of making a decision on a blockchain is provided. The method comprises providing a blockchain voting commitment transaction () redeemable by means of a first signature (σ(A), σ(B)) associated with a selection (A, B) and a second signature (σ(A), σ(B)) associated with the selection, providing each of a plurality of participants (U) with at least one share (k, k) of at least one respective secret value (k, k) wherein a threshold number of shares is required in order to execute said second signature, and submitting the blockchain voting commitment transaction () to the blockchain.

Systems and methods for communication, storage and processing of data provided by an entity over a blockchain network

A computer-implemented method for submitting feedback for an entity to a blockchain is disclosed. The method, which is implemented at one of a plurality of participating nodes, includes: obtaining a first key, the first key being one of a fixed set of keys distributed to participating nodes that are eligible to submit feedback for the entity; generating first feedback (r) of the entity for submission to the blockchain; encrypting the first feedback (r) using at least the first key; and submitting the encrypted first feedback to a mixing service, the mixing service being configured to generate a mixed transaction based on the encrypted first feedback and at least one other encrypted feedback submission from one or more eligible participating nodes.

A method for decision-making on a blockchain includes receiving first public keys from participants, where the first public keys are related to first private keys. The first public keys are combined to generate second public keys, where the second public keys are decisions based on selections among the participants. Third public keys, which correspond to the second public keys, are communicated to the participants. A voting blockchain transaction is generated, where an input script is executed by using a digital signature that corresponds to each participant's first private key, which corresponds to a participant's selection. Output of the voting transaction is a script that represents a decision based on the participants' selections. A payment blockchain transaction is generated, where execution of an output of the payment transaction requires a digital signature that corresponds to a third public key, which corresponds to the decision of the voting transaction.

Computer-implemented decision making system and method

A method of controlling and coordinating of processing steps in a distributed system is disclosed. The method may be implemented by a node in a cyclically ordered set of nodes in a blockchain network. The method includes receiving, from an immediately subsequent node, values corresponding to combinations of possible outcomes of processing steps associated with nodes from that node to a node preceding a supervisor node. The values are based on public keys associated with the nodes corresponding to possible outputs and the supervisor's public key. State values are generated based on the values and public keys corresponding to the possible outcomes further to a processing step of the node shared with the supervisor and a previous node. A blockchain transaction is prepared to transmit control of a resource from the node to the subsequent node upon supply of unlocking values corresponding to the received values.

Computer-implemented methods and systems for controlling tasks implemented by a cyclically-ordered set of nodes participating in a blockchain network

An implementation of the present application provides a computer-implemented method to increase the security of a blockchain-implemented transaction, the transaction including participation from a plurality of participating nodes, each participating node participating as a message originator, selector, and propagator. The method, implemented at a participating node, includes: receiving ciphertext from a prior node and determining whether the participating node is a selector node for said ciphertext received from the prior node. When the participating node is the selector node for said ciphertext, the method includes selecting a subset of said ciphertext, decrypting the selected subset of said ciphertext to provide opted ciphertext and transmitting said opted ciphertext to the next node. When the participating node is other than the selector node for said ciphertext, the method includes decrypting said ciphertext received from the prior node and transmitting the decrypted ciphertext to the next node.

Methods and devices for increasing entropy of a blockchain using blinded outcome diversification

Disclosed herein are a process, an apparatus, and an article of manufacture for storing encrypted documents using a plurality of participating nodes that submit transactions to and/or retrieve transactions from a blockchain network. Functionality disclosed herein includes, but is not limited to, generating a collaborative public key with each of the participating nodes having a share of a corresponding collaborative private key, submitting, based on the collaborative public key and one or more shares of corresponding collaborative public keys, a respective encrypted document to a document repository, submitting a commitment transaction and a subsequent transaction associated with the encrypted document, and, at a future time, retrieving, based on a share of the collaborative public key, a set of subsequent transactions to generate a collective private key and decrypt the encrypted document. In some implementations, hashing operations are involved document encryption, document integrity verification, and document decryption.

Methods and systems for controlling access to, and integrity of, resources on a blockchain

A computer-implemented method for transmitting and/or submitting digital content such as feedback for an entity to a blockchain is disclosed. This may be, for example, the Bitcoin blockchain. The method, which is implemented at a first node, includes: submitting, to the blockchain, a first transaction for committing a first quantity of tokens to transfer to a second node associated with the entity, the first transaction having a first output; generating a first content for submission to the blockchain; and submitting, to the blockchain, a second transaction that returns a second quantity of the committed first quantity of tokens to an address associated with the first node, the second transaction having the first output of the first transaction as an input, wherein the first content is used to unlock the first output of the first transaction.

Blockchain-based systems and methods for communicating, storing and processing data over a blockchain network

This specification describes a system and method that enables multiple blockchain users to exchange their transactions before diffusion over the blockchain network in order to blur the link between the IP address of the transaction generated by a user and the user's blockchain address in the transaction. The system and method provides a technical solution to exchange transactions directly off-chain. Participants in the method agree to make deposits and alter their transaction in such a way that a refund and compensation scheme put in place automatically relies on the confirmations in the blockchain of the transactions exchanged among participants thus providing increased security as well as anonymity. The method scales for an arbitrary number (n>2) of participants.

Computer-implemented system and methods for off-chain exchange of transactions pertaining to a distributed ledger

The invention relates to a method of enabling conditional access to resource. The condition is the performance of a task. The task can be performed by one party or entity on behalf of another party or entity. The person, device or system controlling access to the resource creates a task that includes the broadcast of a transaction on the blockchain. In particular the transaction (part of the task) has a plurality of outputs, including a locking-output. Additional transactions or mechanism are created that enable access to the resource only when the task has been completed. Access to the resource is achieved by (i) the initial broadcast of the resource that makes it conditionally available and (ii) the subsequent broadcast of the transaction, which fulfils or satisfies the condition that enables access to the resource. Multi-signatures and a refund mechanism are used by the parties to lock access to the resource. These multi-signatures are spread between the stages and transactions. The initial deposit broadcast makes the resource available, but access is prohibited because it is locked by a first multi-signature and allocated to a refund mechanism. The task, and transaction to be broadcast, are created wherein the transaction has a locking-output secured by a second multi-signature and also allocated to the refund mechanism. Access to the resource, however, requires both multi-signatures of the refund mechanism to have been signed and the broadcast of the main transaction.

Blockchain-implemented systems and methods for secure access control

A blockchain-implemented transaction from an originator node is to be broadcast. The originator node is communicatively coupled to proxy nodes. The method, implemented by a proxy node, includes: receiving a transaction including an input taking x+r units of computing resources, an output providing x units to the output address and another output providing d+r units to a 1-of-n multi-signature address unlockable by any one of a set of private keys associated the proxy nodes. The proxy node selects a quantity of computing resources, t units, to be allocated to the proxy node for broadcasting the transaction and having it included in the blockchain and generates a further transaction taking d+r units sourced from the multi-signature address and an output providing t units to the proxy node. The proxy node broadcasts both transactions timed to permit their inclusion in the same block of the blockchain.

Security-enhanced origination of blockchain transactions

A method of making a decision on a blockchain is disclosed. First public keys are received from each of a plurality of participants (A, B, C), wherein each first public key represents a possible selection by a participant and is related to a corresponding first private key by a cryptographic operation having a homomorphic property. The first public keys are combined to generate second public keys, wherein each second public key represents a possible decision based on a combination of possible selections. Third public keys, corresponding to the second public keys, are communicated to the participants. A voting blockchain transaction is generated (Tvoting), wherein an input of the voting transaction is a script executable by means of a digital signature corresponding to a first private key of each of a plurality of the participants, wherein each first private key represents a selection made by the participant. An output of the voting transaction is a script representing a decision based on the selections made by the participants. A payment blockchain transaction (Tpayment) is generated for transferring a first digital asset, wherein execution of an output of the payment transaction requires a digital signature corresponding to a third public key corresponding to the decision of the voting transaction.

A method and devices for verifying a digital resource by a plurality of node devices in a blockchain network. The plurality of nodes have respective private key shares, where a collective private key of a collective private-public key pair is based on a set of the respective private key shares, and where each node has a nodal private-public key pair. The digital resource may be encrypted using a digital resource crypto public key, the digital resource crypto public key including combination of a nodal public key and a collective public key. The digital resource may be submitted to a repository system by broadcasting a commitment transaction and a subsequent reveal or rescind transaction of a commitment channel, the commitment channel formed between a respective node and a principal node. Decrypting the encrypted digital resource is based on retrieving private key share contributions from the plurality of nodes participating in verifying the digital resource.

A method of controlling and coordinating of processing steps in a distributed system is disclosed. The method may be implemented by a node in a cyclically-ordered set of nodes participating in a blockchain network. The method includes receiving, from an immediately subsequent node, values corresponding to combinations of possible outcomes of processing steps associated with nodes from that node through to a node immediately preceding a supervisor node. The values are based on public keys associated with the nodes corresponding to possible outputs and the supervisor's public key. State values are generated based on the values and public keys corresponding to the possible outcomes further to a processing step of the node and are shared with the supervisor and an immediately previous node. A blockchain transaction is prepared to transmit control of a resource from the node to the immediately subsequent node upon supply of one of a set of unlocking values corresponding to the received values.

Techniques described herein can be utilized to implement a protocol for performing an unbiased selection of a particular worker node among a plurality of worker nodes to execute a computational task. Nodes of a distributed network may register to join a group membership by generating quantities derived at least in part from a hierarchical data structure, such as an accumulation tree, whose parameters are defined by a manager node. The manager node may utilise the quantities provided by the plurality of worker nodes to perform an unbiased selection of a worker node from among the plurality of worker nodes to perform a computational task. The invention is particularly suited, but not limited to, for use in a blockchain network such as Bitcoin. In at least some cases, the manager node cannot determine, based on quantities supplied by the worker nodes, whether a particular worker node was selected to perform the computational task.

Computer-implemented systems and methods for an accumulator-based protocol for the distribution of tasks across a computer network

The invention relates to distributed ledger technologies such as consensus-based blockchains. Computer-implemented methods for locking and unlocking transaction inputs and outputs are described. The invention is implemented using a blockchain network, which may be, for example, a Bitcoin blockchain. A group of entities form a group in with membership may be proven using an accumulation tree. A variety of methods are described for generating the accumulation tree, including methods that use a central authority and methods that use a decentralized protocol in place of the central authority. In various implementations, parties are able to unlock transaction outputs that are based on group membership without revealing their identity generally.

Growing community of inventors

London, United Kingdom

Pauline Bernat