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: 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. The method is implemented at a participating node that performs steps of: obtaining a subset of the set of indirect token transactions including only those transactions for which the participating node is either an input node or an output node; for each indirect token transaction in the subset, collaborating with a respective second participating node included in the indirect token transaction to generate a commitment channel between the participating node and the second participating node; and collaborating with all other participating nodes in executing the indirect token transactions using the generated commitment channels.

Abstract: A first blockchain transaction is generated where the first blockchain transaction comprises a redeem script, which comprises a cryptographic public key associated with an initiating party and metadata which includes a hash of an exchange-related document, a redeem address, and an amount of digital currency. A second blockchain transaction to spend the digital currency to the redeem address is generated. A response associated with a responding party and comprising a reference to the exchange-related document is generated. The response is stored in a computer-based repository. A further blockchain transaction is generated, the further blockchain transaction comprising a redeem script, which comprises a cryptographic public key associated with the responding party and metadata which includes a hash of the response and a reference to its location in the repository, and an amount of digital currency.

Abstract: The invention provides a secure method for exchanging entities via a blockchain. The invention incorporates tokenisation techniques, and also techniques for embedding metadata in a redeem script of a blockchain transaction.

Abstract: A method of encrypting data at an electronic device where the electronic device is associated with a key device. Each device is associated with an asymmetric cryptography pair, each pair including a first private key and a first public key. Respective second private and public keys may be determined based on the first private key, first public key and a deterministic key. A secret may be determined based on the second private and public keys. The data at the electronic device may be encrypted using the determined secret or an encryption key that is based on the secret. Information indicative of the deterministic key may be sent to the key device where the information may be stored.

Abstract: 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.

Abstract: The disclosure relates to a blockchain-implemented system and method of controlling the transmission and/or distribution of digital content. A first user transfers a deposit quantity of cryptocurrency to a common address. A first node associated with the first user: sends a request to the second node to provide an episode of digital content from a series of digital content; determines a payment transaction to transfer a payment quantity of cryptocurrency to the second user based on a quantity of episodes of digital content in the series; and signs and sends the payment transaction to a second node. The second node associated with the second user: receives the request and the payment transaction; verifies the payment transaction; and based on a result of verifying: provides access to the episode of digital content to the first node; and co-signs and sends the payment transaction to a distributed ledger.

Abstract: A method (300) and system (1) of determining a common secret for two nodes (3, 7). Each node (3, 7) has a respective asymmetric cryptography pair, each pair including a master private key and a master public key. Respective second private and public keys may be determined based on the master private key, master public key and a deterministic key. A common secret may be determined at each of the nodes based on the second private and public keys. In one example, a node (3, 7) may determine the common secret based on (i) a second private key based on the node's own master private key and the deterministic key; and (ii) a second public key based on the other node's master public key and the deterministic key. The invention may be suited for use with, but not limited to, digital wallets, blockchain (e.g. Bitcoin) technologies and personal device security.

Abstract: A computer-implemented method (and corresponding system) is provided, that enables or facilitates the execution of a portion of source code, written in a high-level language (HLL), on a blockchain platform. The method and system can include a blockchain compiler, arranged to convert a portion of high-level source code into a form that can be used with a blockchain platform. This may be the Bitcoin blockchain or an alternative. The method can include: receiving the portion of source code as input; and generating an output script comprising a plurality of op_codes. The op_codes are a subset of op_codes that are native to a functionally-restricted, blockchain scripting language. The outputted script is arranged and/or generated such that, when executed, the script provides, at least in part, the functionality specified in the source code.

Abstract: A computer-implemented method (900) and system (1) for verifying the integrity of a computer software for installation using a distributed hash table (13) and a peer-to-peer distributed ledger (14). This may be the Bitcoin blockchain or an alternative implementation. The method includes determining (910) a metadata associated with a transaction record stored on the peer-to-peer distributed ledger (14). An indication of an entry stored on the distributed hash table (13) may be determined (920) from the metadata. The method further includes determining (930) a third hash value based on the computer software and determining (940) a fourth hash value from the entry on the distributed hash table (13). The method further includes comparing (950) the third hash value and the fourth hash value and verifying (960) the integrity of the computer software based on the comparing of the third hash value and the fourth hash value.

Abstract: The invention provides a secure method for exchanging entities via a blockchain. The invention incorporates tokenisation techniques, and also techniques for embedding metadata in a redeem script of a blockchain transaction. Embodiment(s) provide a method of: generating a first script, the first script comprising: a first set of metadata associated with a first invitation for the exchange of a first entity by a first user, the first set of metadata comprising an indication of the first entity to be offered for exchange and a first location condition for the exchange, a first user public key (P1A) associated with the first user, wherein the first user public key (P1A) is part of an asymmetric cryptographic pair comprising the first user public key (P1A) and a first user private key (V1A).

Abstract: A computer-implemented method (600) and system (1) for verifying ownership of a computer software after installation and prior to execution using a distributed hash table (13) and a peer-to-peer distributed ledger (14). This may be the Bitcoin blockchain or an alternative implementation. The method includes determining (610) a second user public key associated with a second user (24) from a transaction record stored on the peer-to-peer distributed ledger (14). A second public key associated with the second user may be determined (620) from an entry on the distributed hash table (13). The method further includes comparing (630) the second user public key and the second public key, and verifying (640) the ownership of the computer software based on the comparing of the second user public key and the second public key.

Abstract: A computer-implemented method (600) and system (1) for verifying ownership of a computer software for installation using a distributed hash table (13) and a peer-to-peer distributed ledger (14). This may be the Bitcoin blockchain or an alternative blockchain implementation. The method includes determining (610) a second user public key associated with a second user (24) from a transaction record stored on the peer-to-peer distributed ledger (14). A second public key associated with the second user may be determined (620) from an entry on the distributed hash table (13). The method further includes comparing (630) the second user public key and the second public key, and verifying (640) the ownership of the computer software based on the comparing of the second user public key and the second public key.

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 OR, AND, XOR, NOT and so on. In some examples, the instructions may be provided in a hashed form. 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 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. Thus, the locking script of the first transaction provides the functionality of the desired logic gate.

Abstract: A method and system for generating a transaction for a blockchain protocol are disclosed. The method comprises using a software resource to receive, generate, or derive at least one data item, insert, at least once, a portion of code into a script associated with the transaction, where the script is written in a language that is functionally restricted. Upon execution of the script, the portion of code provides functionality of a control flow mechanism controlled or influenced by the at least one data item. The method further comprises using the software resource to generate the blockchain transaction comprising the script and submit the blockchain transaction to a blockchain network.

Abstract: The invention relates to blockchain technologies such as the Bitcoin ledger, and for the control and performance of secure, efficient exchanges conducted via the blockchain. It comprises tokenisation techniques and methods for embedding metadata in a blockchain transaction.

Abstract: The invention comprises a computer-implemented method and system for controlling an exchange process, such as a loan, conducted between at least two parties via a blockchain such as the Bitcoin blockchain. A method according to the invention may comprise the step of generating a first blockchain transaction which includes a redeem script. The redeem script comprises a cryptographic public key associated with an initiating party and metadata which includes a hash of an exchange-related document; a redeem address; and an amount of digital currency. A second blockchain transaction is generated and published to the blockchain so as to spend the digital currency to the redeem address. This provides the advantage that the further transaction will be publically available and thus detectable by other parties once it has been published. The further transaction can provide the information necessary to trigger a response e.g. an offer from another (responding) party who publishes their response on the blockchain.

Abstract: A computer-implemented method (100) and system (1) for determining a metadata M for securing a controlled digital resource such as computer software using a distributed hash table (13) and a peer-to-peer distributed ledger (14). This is a blockchain such as the Bitcoin blockchain. The method includes determining (110) a data associated with the computer software and determining (120) a first hash value based on the computer software. A second hash value based on the data and the computer software may be determined (130). The method further includes sending 140, over a communications network (5), the data, the first hash value and the second hash value to an entry for storage in a distributed hash table (13). The second hash value may be a key of a key-value pair. The data and the first hash value may be a value in the key-value pair. A metadata (M) that is based on the second hash value may be determined (150) for storage on the peer-to-peer distributed ledger (14).

Abstract: A method of creating, redeeming, and transferring tokens on a peer-to-peer distributed ledger including generating a blockchain transaction having an output related to a quantity of cryptocurrency, and a hash of a redeem script usable for spending the output. The redeem script comprises metadata, which in turn comprises a token representing a tokenised entity. The redeem script additionally comprises at least one public cryptographic key. The metadata is provided in the redeem script at a location designated in the underlying blockchain protocol as a location for a cryptographic key.

Abstract: A computer-implemented method (and corresponding system) is provided that enables or facilitates the execution of a portion of source code, written in a high-level language (HLL), on a blockchain platform. The method and system can include a blockchain compiler, arranged to convert a portion of high-level source code into a form that can be used with a blockchain platform. This may be the Bitcoin blockchain or an alternative. The method can include: receiving the portion of source code as input; and generating an output script comprising a plurality of op codes. The op codes are a subset of op codes that are native to a functionally-restricted, blockchain scripting language. The outputted script is arranged and/or generated such that, when executed, the script provides, at least in part, the functionality specified in the source code.