Abstract: A computer-implemented method of generating shares of private keys, wherein the method is performed by a first participant of a group of participants and comprises: obtaining a first seed share, wherein each other participant has a respective seed share; generating a first master private key share of a shared master private key, wherein the first master private key share is generated based on the first seed share and the respective seed share of each other participant, and wherein each other participant has a respective master private key share; and generating one or more first private key shares based on the first master private key share, wherein each first private key share is a share of a respective shared private key.

Abstract: The invention provides a novel and advantageous method and corresponding system. The invention is implemented via a distributed electronic ledge (blockchain). This may or may not be the Bitcoin blockchain. The invention is suited for the exchange or transfer of an asset, e.g. a digital asset, such as tickets and the like (but not limited in this regard).

Abstract: A method performed in a layered network. The layered network comprises a core layer comprising one or more core nodes, one or more intermediate layers each comprising one or more intermediate layer nodes, and one or more outer layers each comprising one or more outer layer nodes. Each of the core nodes is a node of a blockchain network. One or more intermediate layer nodes are smart contracts nodes providing a smart contract service for maintaining the state of a smart contract. One or more outer layer nodes are client nodes of the smart contract service. The method included, by a smart contract node: recording a state of the smart contract in a record of the state maintained at the first smart contract node. In addition, at least a first transaction also recording the state is recorded on a blockchain of the blockchain network.

Abstract: The invention relates to distributed ledge technologies such as consensus-based blockchains. Computer-implemented methods for a secure random number generation within blockchain scripts are described. The invention is implemented using a blockchain network, which may be, for example, a Bitcoin blockchain. A third transaction is validated. The third transaction is associated with a third digital asset and includes a first and second puzzle in a locking script. The first puzzle is included, in a first transaction, in a first locking script that encumbers transfer of control of a first digital. The second puzzle is included, in a second transaction, in a second locking script that encumbers transfer of control of a second digital asset. A pseudorandom number is generated based at least in part on solutions to the first and second puzzles. Control of the third digital asset is transferred based at least in part on the pseudorandom number.

Abstract: A computer-implemented method is disclosed. The method includes providing a blockchain transaction comprising a public key combination verification function. The blockchain transaction is configured to be redeemable to permit access to, or transfer control of, a resource by providing to the blockchain transaction an input comprising: a plurality of public keys; a gradient value (?) related to two of the plurality of public keys; and a group public key derived from a combination of the public keys and the gradient value (?). The blockchain transaction is configured to apply the public key verification function to the input to verify, upon successful redemption of the transaction, that the group public key is derived from the combination of the plurality of public keys.

Abstract: Systems and methods described herein relate to the execution of locking transactions in a blockchain system. In the context of smart contracts, it may be advantageous to have a public record (e.g., recorded on a blockchain) of a proof of correct execution of a circuit published by a worker and the verification key, thereby allowing anyone (e.g., nodes of the blockchain) to verify validity of the computation and proof. However, there are challenges to recording large blocks of data (e.g., large keys that may comprise multiple elliptic curve points) on the blockchain. For example, in a Bitcoin-based blockchain network, a protocol that utilizes standard transactions may be constrained to locking scripts and unlocking scripts that are collectively no t larger than a first predetermined size limit, and the size of a redeem script (if utilized) may be limited to being no more than a second predetermined size limit.

Abstract: A computer-implemented method of representing a first set of data items, wherein the method is performed by a first tree generator and comprises: allocating the first set of data items into a plurality of respective subsets; for each respective subset of data items, generating a respective hash tree based on the respective subset of data items, wherein the respective hash tree comprises a respective root node; and generating a respective first hash set representing the first set of data items, wherein the first hash set comprises each of the respective root nodes.

Abstract: A computer-implemented method of generating blockchain transactions, wherein the method is performed by a first party and comprises: generating a first blockchain transaction, wherein the first blockchain transaction comprises a first compact script (CS), wherein the first CS is at least partly written in a high-level (HL) scripting language and comprises one or more HL functions, wherein when executed, each HL function is configured to perform an operation equivalent to a respective operation performed by one or more low-level (LL) functions of a LL scripting language, wherein the first CS is configured to perform an operation equivalent to a first expanded script (ES) written in the LL scripting language and comprising a plurality of LL functions, and wherein the first CS is smaller in storage size than the first ES; and making the first blockchain transaction available to one or more nodes of a blockchain network and/or a second party.

Abstract: A computer-implemented method and system is provided which enables interaction between a device and an asset transfer platform. The method may be implemented by a processing resource through the cloud or through a collection of localised hardware or software resources. A message is received from a client device associated with a user. The message may comprise at least one identifier of a message type associated with the message. This may be implemented using a parameter in an API call. This may also be implemented using a parameter in a message transmitted using a data communications network. The message may also comprise at least one identifier associated with a profile registered on the asset transfer processing platform, wherein the profile relates to at least one event stream provided by the asset transfer processing platform, wherein the at least one event stream is associated with at least one asset type.

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: A computer-implemented method includes encrypting a plaintext message to a cryptographic public key in accordance with an identity-based encryption scheme using at least a congress public key to generate an encrypted message, wherein the congress public key is associated with members of a congress, respective members of the congress having access to private key shares usable in a threshold decryption scheme in which at least a threshold of private key shares are sufficient to derive a decryption key through the combination of partial contributions to the decryption key on behalf of the congress, generating, using at least a cryptographic private key corresponding to the cryptographic public key, a digital signature over a first set of instructions to perform cryptographic operations upon an occurrence of an event; and broadcasting one or more transactions to a proof-of-work blockchain network, the one or more transactions comprising the encrypted message, the cryptographic public key.

Abstract: Presented herein are one or more embodiments with novel techniques of: defining an asset comprising at least one private cryptographic key, each private cryptographic key being associated with an owner of the asset; generating a registry comprising at least one public cryptographic key; generating a smart contract comprising at least one rule relating to an automated generation of one or more blockchain transactions to enable a transfer to be made in respect of the asset; and using a computing agent to evaluate and/or execute the at least one rule of the smart contract. Thus, one benefit provided by the invention is that it allows the secure distribution of costs and income for an asset registered and maintained on the Blockchain, which, in turn increases the capability of such assets to meet the real-world needs of various entities such as the asset itself and investing parties.

Abstract: Computer-implemented methods and systems suitable for implementation in nodes of a blockchain network are provided. Modified blockchain node structures, network architectures, and protocols for handling large numbers of transactions and large transaction blocks are described. A computer-implemented method for a node of a blockchain network is described which includes: receiving mined data from the blockchain network corresponding to a plurality of validated transactions; assembling blocks based on said mined data; and sending assembled blocks to a storage entity for storing on a blockchain.

Abstract: The computer-implemented invention provides a method and corresponding system for controlling access to and/or use of an internet-enabled resource. The invention uses a distributed electronic ledger such as, for example, the Bitcoin blockchain. The resource may be an IoT device or system. Access to the resource is permitted or enabled upon provision of a cryptographic key e.g. a private key which corresponds to a public key which has been stored in memory. In one embodiment, the public key is stored in a DHT. Access to the resource is prevented or disabled by removing the public key from memory, and using a redeem script of a blockchain Transaction to spend a tokenised output of a further blockchain Transaction. The process of communicating the requisite cryptographic keys and transferring funds is performed via the blockchain. The keys are communicated as tokens in the metadata of transactions scripts. In use, when access is requested by the user, an encrypted message is sent to the resource.

Abstract: A method for blocking sensitive data in a message, the method performed on a computing device and comprising: creating a copy of said message; generating at least one zero knowledge proof, the generating of each of said at least one zero knowledge proof comprising: obtaining a mask bit string which identifies locations of at least one sensitive bit in bits of said copy; computing a public bit string by modifying said bits of said copy by assigning the at least one sensitive bit with a predetermined value; determining a secret bit string which includes said at least one sensitive bit and satisfies a requirement that said bits of said copy are equal to an output of a bitwise logical calculation using the public bit string, the mask bit string and the secret bit string; hashing the copy of said message or a portion thereof to generate an output hash value; and generating a zero knowledge proof using the public bit string, the mask bit string, the output hash value, the secret bit string; removing each of said at

Abstract: The present disclosure relates to methods, devices and/or systems associated with a transaction for a distributed ledger, such as the Bitcoin blockchain. In some embodiments, the present disclosure relates to a method for performing payer entity validation, based on the request. In other embodiments the present disclosure relates to a method for implementing asynchronous processing of a request sent by a payer entity, when a payee entity is non-responsive.

Abstract: A method for enabling a verifying party to verify an identity of a target party or device. The method comprises, in a set-up phase: storing, in a data store, a respective piece of response data for each of a set of one or more responses resulting from a setting-up party inputting a respective set of one or more challenges into a PUF module comprising a physically unclonable function, PUF, to generate the one or more responses based on the PUF; and storing an indication of the set of challenges in the data store. The indication does not comprise a value of each of the challenges in the set, but rather a master challenge from which the set of challenges is derivable by applying a derivation function to the master challenge.

Abstract: Validator nodes and methods of operating a validator node to process blockchain transactions. The validator node provides a plurality of mining nodes with access to a set of unconfirmed transactions, typically by providing a hash of those transactions, in exchange for a token from each of the mining nodes. If one of the plurality of mining nodes successfully mines a block containing the set of unconfirmed transactions, the validator node refunds the token to that mining node and retains the remaining tokens. If a miner other than one of the plurality of mining nodes successfully mines a block before any of the plurality of mining nodes is able to mine a block containing the set of unconfirmed transactions, then the validator node transfers to each of the plurality of mining nodes a modified token.

Abstract: The invention provides a computer-implemented method for performing an exchange via a blockchain, comprising the step of submitting a funding transaction to the blockchain network, wherein the funding transaction i) comprises a tokenised contract relating to an asset to be transferred from a second user to a first user; and ii) is signed by the first user. It also comprises the step of sending, from the first user to the second user, one or more subsequent transactions wherein each said subsequent transaction spends an output of the funding transaction and is signed by the first user. It includes the step of submitting one of the subsequent transactions to the blockchain network, the submitted transaction having been signed by the second user.

Abstract: 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.