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: The computer implemented invention provides a method, corresponding systems and arrangement within a network for detecting changes in the topology, ordering those changes by occurrence and constructing a new topology reflecting the changes. The invention addresses problems with keeping the knowledge of the network topology at each network node current, particularly when the network topology is dynamic, i.e. when links fail and recover at arbitrary times. The topology updating is event driven, as it is activated when some change in the network, particularly with nodes and links occurs. Events cause topology changes to be reported to other nodes in the network. Timestamping of messages allows the messages to be correctly applied as the most recent update or discarded. An algorithm is provided that allows each merchant node to maintain a correct view of the network topology despite link and node failures.

Abstract: A computer-implemented access method is provided. The method comprises the steps of: (i) submitting, to a blockchain (such as the Bitcoin blockchain), an access blockchain transaction addressed to a derived public key derived at least in part from a secret value and a public key; (ii) generating a verification public key based at least in part on the secret value and the public key; (iii) comparing the derived public key and the verification public key; and (iv) based on the comparison of step (iii): (a) allocating the at least one of the derived and verification public key as a further public key for verifying a further derived public key; and (b) granting access to a resource associated with at least one of the secret value and the derived public key.

Abstract: This invention relates generally to blockchain implementations and is suited for, but not limited to, use with the Bitcoin blockchain. It can be used for the implementation of automated processes such as device/system control, process control, distributed computing and storage and others. The invention provides an event detecting, monitoring and/or counting mechanism. The event may be, for example, a vote, decision or selection which is made by a given entity. The invention provides a counting solution in which a computing resource, running simultaneously and in parallel to the blockchain, manages a loop-based operation. The computing resource continuously monitors the state of the blockchain as well as any other off-blockchain input data or source. The execution of the loop is influenced by the state of the blockchain. Each iteration of the loop that is executed by the computing resource is recorded in a transaction that is written to the blockchain. It is stored as a hash within the transaction's metadata.

Abstract: A computer-implemented method of validating a blockchain transaction is disclosed. The method comprises requesting at least one UTXO referenced by at least one respective input of the transaction from a member node of at least one shard comprising at least one UTXO, obtaining validity data of at least one UTXO from at least one node, and performing a validation check on at least one input using the validity data.

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: The invention relates generally to cryptographic techniques for secure processing, transmission and exchange of data. It also relates to peer-to-peer distributed ledgers such as (but not limited to) the Bitcoin blockchain. In particular, it relates to control solutions for identifying, protecting, extracting, transmitting and updating data in a cryptographically controlled and secure manner. It also relates to system inter-operability and the ability to communicate data between different and distinct computing systems.

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 determining the validity of a token (T) associated with a quantity of cryptocurrency is provided. In some embodiments, the method comprises: a second user (B) receiving, over a communications network, a first transaction comprising a transfer of the token (T) from a first user (A) to the second user (B), querying a peer-to-peer distributed ledger to determine whether an authenticated transaction associated with the token (T) can be identified, wherein the authenticated transaction comprises a previous transaction associated with the token (T) and wherein the token (T) has been authorised and responsive to identifying an authenticated transaction, determining that the token (T) is valid.

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

Abstract: The invention presents a solution in which blockchain Transactions are created to implement the functionality of a logic gate. The invention may be implemented on the Bitcoin platform or an alternative blockchain platform. The transaction includes a locking script which comprises instructions selected so as to implement the functionality of a logic gate, such as the XOR gate. When the script is executed (because a second transaction is attempting to spend the output associated with the locking script) the inputs will be processed by the conditional instructions to provide an output of TRUE or FALSE. The inputs are pre-processed by one or more computing agents so that they are evaluated to TRUE or FASLE prior to being used as inputs to the script. The second transaction is transmitted to the blockchain network for validation and, if determined to be valid, it will be written to the blockchain. Validation of the second transaction can be interpreted as a TRUE output.

Abstract: Computer-implemented methods for locking a blockchain transaction based on undetermined data are described. The invention is implemented using a blockchain network. This may, for example, be the Bitcoin blockchain. A locking node may include a locking script in a blockchain transaction Node to lock a digital asset. The locking script includes a public key for a determined data source and instructions to cause a validating node executing the locking script to verify the source of data provided in an unlocking script by: a) generating a modified public key based on the public key for the determined data source and based on data defined in the unlocking script; and b) evaluating a cryptographic signature in the unlocking script based on the modified public key. The blockchain transaction containing the locking script is sent by the locking node to the blockchain network. The lock may be removed using a cryptographic signature generated from a private key modified based on the data.

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 provides a method and corresponding system for controlling the generation of a blockchain transaction, and/or the recipient of a transaction output. It can also be used to control and record the ownership of an asset represented on the blockchain without the need for a separate registry of ownership. The ownership and transfers thereof can be handled and recorded without the need for knowledge of the parties involved or their identities. According to one embodiment, the method comprises the steps of identifying at least one transaction (Tx) on a blockchain which comprises: an unspent transaction output (UTXO) relating to a tokenised asset associated with an asset controller; and an input which spends an output from a previous transaction that is locked by a redeem script hash.

Abstract: A method in accordance with the invention includes: providing to a hub, from an enclave associated with a TEE at a node, an enclave public key; establishing a channel with the hub by broadcasting to a blockchain network a funding transaction which encumbers a digital asset with a first public key, a second public key and a third public key such that the encumbrance of the digital asset may be removed by: 1) both a first signature generated from a first private key corresponding to the first public key and a second signature generated from a second private key corresponding to the second public key; or 2) a third signature, valid for the third public key, the third public key associated with a group; receiving a commitment transaction encrypted with the enclave public key; detecting a failure; and issuing a failsafe activation request to the group using data from the enclave.

Abstract: 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 utilised 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.

Abstract: A method of sharing a secret value is disclosed. The method comprises distributing respective first shares of a first secret value, known to a first participant (Pi), to a plurality of second participants (Pj?i), wherein said first shares are encrypted by means of at least one private-public key pair comprising a private key and a public key being an elliptic curve generator point multiplied by the private key and wherein a first threshold number of first shares is required in order to enable a second participant to determine the first secret value.

Abstract: The invention provides a blockchain-implemented control method and corresponding system(s). The invention may control access to an internet-enabled resource such as an IoT device that is provided with computing capabilities enabling it to communicate with other computer-based resources and interact with a distributed ledger. In one embodiment, the invention provides a method for controlling the use of an internet-enabled resource comprising providing a first blockchain transaction comprising at least one output which is redeemable only by provision of at least: i) a secret value selected by a user; and ii) a signature associated with a resource provider; sending use-related information to the resource; generating a second blockchain transaction requesting at least the secret value; and modifying the second blockchain transaction to include the secret value.

Abstract: The invention relates to blockchain technologies such as the Bitcoin blockchain. The invention uses a novel technique to decompose the functionality of a blockchain transaction script into several chunks or functional parts, and to use the output of a chunk as the input of the next chunk. Advantageously, this allows the blockchain to be used for ever complex tasks and computations while minimising script size, and also provides a novel architecture for the distributed execution of computational processes.

Abstract: The invention relates to distributed ledger technologies such as consensus-based blockchains. A blockchain transaction may include digital resources that are encumbered by a locking script that encodes a set of conditions that must be fulfilled before the encumbered resources may be used (e.g., transferring ownership/control of encumbered resources). A worker (e.g., a computer system) performs one or more computations to generate a proof, which is encoded as part of an unlocking script. A verification algorithm may utilize the proof, a verification key, and additional data such as a cryptographic material associated with the worker (e.g., a digital signature) to verify that digital assets of the transaction should be transferred. As a result of the validation of this transaction, any third party is able to check the contract was executed corrected rather than re-executing the contract, thus saving computational power.