Abstract: A method of obtaining digitally signed data is disclosed. The method comprises sending first data (e2)from at least one of a plurality of first participants to at least one second participant, wherein the first data is based on second data (e) accessible to at least one said first participant, and the second data is inaccessible to the or each said second participant. A digital signature (s1) of the first data is received from at least one said second participant, and the digital signature of the first data is processed, by a plurality of the first participants, to provide shares of a digital signature (s) of the second data, wherein the digital signature of said second data is accessible by means of a threshold number of said shares and is inaccessible to less than said threshold number of shares.

Abstract: A computer-implemented method for participating in a blockchain-based data record distribution process which includes multiple input addresses for input nodes and multiple output addresses for output nodes. One or more input nodes of the group of input nodes perform steps of: collaborating to determine a stealth address, forming a first transaction that pools data records to be transferred to the stealth address, and transmitting the first transaction to be validated and incorporated into the blockchain. One or more output nodes of the group of output nodes perform steps of: searching the blockchain to find the first transaction, identifying the stealth address, forming a second transaction that distributes pooled data records, collaborating via a threshold signature scheme to sign the second transaction, and transmitting the second transaction to be validated and incorporated into the blockchain. The invention may be used in conjunction with any blockchain implementation.

Abstract: Embodiments of the present disclosure provides protocols, methods and systems which provides advantages such as the resistance of centralisation of mining on a blockchain network, preferably a Proof-of-Work blockchain. A method in accordance with an embodiment may comprise generating a plurality of non-parallelisable challenges (or “puzzles”) and allocating one of said plurality of challenges to each miner on the network. The miner uses an inherently sequential (non-parallelisable) algorithm to find a solution to his allocated challenge. The challenges are generated by a committee of nodes, and a new set of challenges is generated for each block.

Abstract: A computer-implemented method of distributing a shared secret on a blockchain network. The method comprises mapping a plurality of inputs to elliptic curve points of an elliptic curve of an elliptic curve cryptography system. In a first encryption step, a plurality of the elliptic curve points are encrypted by a public key of a public-private key pair and decryptable by the corresponding private key of the public-private key pair. In a second encryption step, a plurality of parts of one input to a second encryption step are multiplied by terms of a series known to participants. In a secret sharing step, a plurality of shares of an input to a secret sharing step are distributed to a plurality of said participants, and an input is accessible to a threshold number of shares and is inaccessible to less than a threshold number of shares.

Abstract: The invention comprises a solution for securing an output (UTXO) in a single blockchain (e.g. Bitcoin) transaction (TX) so that it can only be unlocked by an authorised party at an allowed time, and in accordance with external data supplied to the transaction's locking script. The invention may comprise two steps which are implemented within a redeem script provided within the UTXO's locking script: 1) Calculation of a time-related value (which we will call Tsupplied) using the external data provided; and 2) use of the calculated Tsupplied value in a time lock technique to ensure that unlocking occurs at a time pre-determined time. The invention allows external data to be introduced into the time lock control of a transaction on the blockchain. It also includes a technique for combining absolute and relative time locks (e.g. CLTV and CSV as known in the Bitcoin protocol).

Abstract: The invention relates to the fields of tokenisation, blockchain and smart contract technologies. It provides a technical arrangement which simplifies the automated management of contracts. The invention comprises a method and system which use a computer-based repository for storage of the contract. The contract is then represented by a transaction on the blockchain. Metadata within the transaction's script includes a hash of the contract and a means of identifying its location within the repository. The transaction also includes an unspent output (UTXO) which indicates its status as an open (ie not terminated) contract. The contract is terminated by spending the output at a later point in time, for example, using nLockTime+CheckLockTimeVerify (CLTV). By combining this concept with other techniques and computing components, the invention can provide a powerful mechanism for implementing various tasks such as renewing or rolling over the contract, or dividing it into sub-contracts or conditions.

Abstract: According to a first aspect disclosed herein there is provide a device comprising: a PUF module, and one or more outer layer components providing at least part of an unsecured channel for inputting a challenge to the PUF module and receiving back a response. Internal logic of the PUF module comprises a logging mechanism arranged to automatically log a record of the challenge and/or response in a log medium, e.g. a blockchain. According to a second aspect, there is provided a method comprising: sending a first message to be recorded on a blockchain, submitting a query to check that the first message has been recorded on the blockchain without manipulation, on condition thereof, sending a second messaging transaction to be recorded on the blockchain. The first and second aspects may be used together or independently.

Abstract: According to a first aspect of the disclosure, there is provided a request-response protocol for requesting access to data from a destination transaction. According to a second aspect of the disclosure, there is provided a method of accessing data from one or more destination transactions stored on a blockchain, wherein the method comprises selecting one or more hyperlinks linking to the destination transaction(s).

Abstract: Hemofilters for in vivo filtration of blood are disclosed. The hemofilters disclosed herein provide an optimal flow of blood through the filtration channels while maintaining a pressure gradient across the filtration channel walls to enhance filtration and minimize turbulence and stagnation of blood in the hemofilter.

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: Techniques are presented for securely transmitting a output script or information associated with a payroll and a user between a first node and a second node. The method comprises: determining a symmetric-key based on a common secret, based on a first node second private key and a second node second private key, wherein the second node has the same common secret based on a first node second public key and a second node second private key; encrypting at least part of the output script or information associated with the payroll and the second node with the symmetric-key, to an encrypted output script or encrypted information associated with the payroll and the second node; and sending the encrypted output script or encrypted information associated from the first node to the second node.

Abstract: A computer-implemented method of creating different versions of a tree structure overlaid on a blockchain, wherein the method is performed by a tree creator and comprises: creating one or more target child nodes of a target parent node, each target child node comprising a respective data payload; and forming a respective edge between each target child node and the target parent node by associating each of the target child nodes with a respective link identifier, wherein the respective link identifier is based on at least one off-chain parameter.

Abstract: The invention provides methods and systems which enable additional functionality to be inserted into blockchain scripts with ease and in an effective and manner. According to one embodiment, the invention provides a blockchain-implemented method comprising the steps of arranging a plurality or selection of scripting language primitives to provide, upon execution, the functionality of a high-level scripting language primitive, wherein the scripting language is associated with a blockchain protocol; inserting the plurality of scripting language primitives at least once into a script; and inserting the script into blockchain transaction (Tx). The high-level scripting language primitive may perform, for example, an arithmetic operation such as multiplication or division. The scripting language primitives may be called op-codes, words or commands, and are native to the scripting language. The scripting language may be Script, and the blockchain protocol may be a version of the Bitcoin protocol.

Abstract: The present invention relates to a novel dice game device. The device is a modified dice game in which players roll different combinations of dice to enter into different areas of a scoresheet. Players earn points based on the combinations they roll to try and win the game. The game introduces the concept that five-of-a-kind numbers, (i.e., 2 thru 5), can be five-of-a-kind and/or a player can split the difference to achieve five-of-a-kind. The game introduces the concept that four-of-a-kind numbers (2 thru 6) with three of the same number can add the two remaining dice together to equal the same number as the three-of-a-kind number already scored to equal four-of-a kind. The game introduces the concept of wild cards that can be entered in any available score area for the maximum point available in that score area.

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: 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 system is provided for performing transaction mixing between a plurality of users on a blockchain. The system is configured to carry out the steps of: selecting an initiator node to calculate a deterministic hash function using a chosen random number; distribute the deterministic hash function to a plurality of users on the blockchain; choose an amount of time each user is given to construct a payment channel, retrieve the random number, and submit an execution transaction to a blockchain network; choose a second time for when a payment to a user is submitted to the blockchain network; and establish a one-way payment channel between every pair of users in an ordered set of the plurality of users to establish a transaction chain linking all users.

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: Techniques are presented for controlling or influencing use of and/or access to a resource. This resource may be a device, such as an IoT (Internet of Things) device or a process. Techniques include a method comprising generating a blockchain transaction (TxA) indicative of a condition on use of, or access to, the resource for a specified period of time, the blockchain transaction comprising a multi-signature script requiring a plurality of signatures for completion of the blockchain transaction; providing a first subset of the plurality of signatures to the blockchain transaction (TxA) to generate a partially signed signature script to partially complete the blockchain transaction (SI 14); and responsive to the condition on the use of, or access to, the resource being satisfied, providing a second subset of the plurality of signatures (S204) to the blockchain transaction to fully complete the blockchain transaction.

Abstract: A computer-implemented access method is provided. The method comprises the steps of: (i) providing a verification data item of a one-way function chain of data items; (ii) submitting, to a blockchain (such as the Bitcoin blockchain), an access blockchain transaction comprising a data item of the chain; (iii) applying the one-way function to the data item to provide an output; (iv) comparing the output of step (iii) to the verification item to provide an outcome; and (v) based on the outcome of step (iv): (a) allocating the output as a further verification data item for verifying a further data item of the chain; and (b) granting access to a resource associated with the data item.