Abstract: A method for propagating data packets in a network of nodes is disclosed.

Abstract: A method of propagating data packets in a network of nodes is disclosed. This may be a blockchain network such as, for example, the Bitcoin network.

Abstract: A computer-implemented method to initiate a token transfer process for transferring respective first quantities of tokens between a plurality of pairs of sender nodes and respective recipient nodes using a blockchain.

Abstract: A computer-implemented method to participate in a token transfer process for transferring a first quantity of token from a sender node to a recipient node using a blockchain is disclosed. The token transfer process includes a plurality of participating nodes and execution of a set of indirect token transactions between multiple pairs of the participating nodes.

Abstract: 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.

Abstract: There may be provided a blockchain-implemented security method involving a requestor and a group of nodes, which includes generating a cryptographic key of the requestor based on a password chosen by the requestor and first quantities sent by the group of nodes (which are derived from private key shares of the group of nodes and a generator function of a digital signature scheme employing a bilinear mapping on an elliptic curve). A cryptographic signature for a requestor blockchain transaction can be generated where the signature corresponds to the requestor's cryptographic key. The signature can be based on the password and second quantities sent by the group of nodes (which are also derived from the group private key shares). The method can further include verifying the cryptographic signature of the blockchain transaction using the requestor's cryptographic key.

Abstract: 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 (rj) of the entity for submission to the blockchain; encrypting the first feedback (rj) 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.

Abstract: A computer-implemented includes sending a public key associated with a particular node in a cyclically-ordered set of nodes participating in a blockchain network to an initiator node; receiving, by the particular node from a node immediately previous to the particular node in the cyclically-ordered set, a first value based on public keys associated with each node from the particular node through to the initiator node; determining a locking value based on the first value and the public key associated with the particular node; and preparing using the locking value, a transaction arranged to transmit control of a resource from a source address associated with the particular node to a receiving address of a node immediately subsequent to the particular node. The control of the resource is to be transmitted responsive to satisfaction of an execution condition including supply of an unlocking value corresponding to the locking value.

Abstract: 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.

Abstract: Techniques described herein may be utilised to implement methods and systems for lossless compression and serialisation of arithmetic circuits to a bit stream using compression techniques such as the arithmetic coding. An arithmetic circuit representing a smart contract may be compressed using arithmetic coding, thereby generating a compressed arithmetic circuit that can be stored or broadcast to a blockchain network using less computational resources (e.g., data storage resources) than would otherwise be needed to store the arithmetic circuit. The arithmetic circuit can be efficiently compressed using entropy coding based on the frequency of elements in the data structure, such as the arithmetic operator types. Instructions for de-serialisation and de-compression can also be embedded in the bit stream, and can be used (e.g., by another computer system) to reconstruct the original circuit in a lossless manner.

Abstract: A method of propagating data packets in a network of nodes is disclosed. The method, implemented at one of the nodes, includes: collecting a set of first data packets during a first time period, the set including at least one data packet received from one or more first nodes in the network; obtaining a plurality of encoded data packets, each one of the plurality of encoded data packets being generated by combining two or more first data packets of the set using network coding; determining a mapping of the plurality of encoded data packets and the first data packets of the set to one or more neighbouring nodes connected to the node; and transmitting the plurality of encoded data packets and the first data packets of the set to the one or more neighbouring nodes according to the determined mapping.

Abstract: 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.

Abstract: 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.

Abstract: A method of propagating data packets in a network of nodes is disclosed.

Abstract: A method of propagating data packets in a network of nodes is disclosed. The method, implemented at one of the nodes, includes: generating at least one data packet of a first type; collecting a set of data packets of the first type during a first time period, the set including the at least one generated data packet and at least one data packet of the first type received from one or more first nodes in the network; and for each data packet in the set: randomly select two or more neighbouring nodes connected to said one of the nodes; transmit, to each of the two or more selected neighbouring nodes: the data packet, wherein the two or more selected neighbouring nodes are configured to relay the data packet to one or more second nodes in the network using a mode of data propagation that is arbitrarily selected for that neighbouring node. The invention is particularly suited for implementation on a blockchain network such as, for example, the Bitcoin blockchain.

Abstract: There may be provided a blockchain-implemented security method. It may be implemented using a blockchain network. Embodiments of the blockchain-implemented security method involve a first party and a second party. The blockchain-implemented security method generates a plurality of n cryptographic locks based on combinations of encrypted versions of a first plurality of n secrets generated by the first party and encrypted versions of a second plurality of n secrets generated by the second party. One secret belonging to the first plurality of n secrets generated by the first party is randomly selected. And a cryptographic key that unlocks a particular cryptographic lock of the plurality of n cryptographic locks is generated, wherein the particular cryptographic lock corresponds to the randomly selected one secret belonging to the first plurality of n secrets generated by the first party.

Abstract: A computer-implemented method of making a decision on a blockchain is provided. The method comprises providing a blockchain voting commitment transaction (2) redeemable by means of a first signature (?(Am), ?(Bm)) associated with a selection (A, B) and a second signature (?(A), ?(B)) associated with the selection, providing each of a plurality of participants (Ui) with at least one share (kA,i, KB,i) of at least one respective secret value (kA, kB) wherein a threshold number of shares is required in order to execute said second signature, and submitting the blockchain voting commitment transaction (2) to the blockchain.

Abstract: A computer implemented method and system is described which uses blockchain technology as a storage system for data acquired from a set of digital twins. The blockchain can be used to generate an immutable transaction history of data produced by the set of digital twins. In the case of an error or failure, parties of interest can then access and analyse an immutable record of data. The invention may be used in conjunction with the Bitcoin blockchain or another blockchain protocol.

Abstract: 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.

Abstract: 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 (Tc) for committing a first quantity (x) of tokens to transfer to a second node associated with the entity, the first transaction (Tc) having a first output; generating a first content for submission to the blockchain; and submitting, to the blockchain, a second transaction (Tf1) that returns a second quantity (d) of the committed first quantity (x) of tokens to an address associated with the first node, the second transaction (Tf1) having the first output of the first transaction (Tc) as an input, wherein the first content is used to unlock the first output of the first transaction (Tc).