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.

Abstract: The present disclosure provides a method of implementing a payment service for one or more clients for transactions associated with a distributed ledger, such as the Bitcoin blockchain. The method comprises providing an alias for a client, associating the alias with a network in a directory and providing a location for a host computing resource responsible for the payment service, wherein the host computing resource is configured to facilitate identification of the client associated with the alias. The present disclosure also provides a method comprising creating a machine readable resource in a location associated with the payment service, wherein the machine readable resource comprises an endpoint identifier for the payment service, an entry associated with at least one capability supported by the payment service, and instructions and/or a specification for accessing a public address for facilitating transactions associated with the alias.

Abstract: A server of media content makes a first transaction available to users that includes a first output specifying an amount of a digital asset to transfer to a second party, and a total of zero or more inputs wherein a total input amount of the digital asset specified in any outputs of any source transactions pointed to by the zero or more inputs is less than a total output amount of the digital asset specified by the one or more outputs. Inputs are received from users of a side channel. Once a target is reached, the first transaction and a second transaction are recorded in a blockchain, wherein the second transaction comprises an input pointing to the first output of the first transaction and an unlocking script meeting a condition that requires the unlocking script to include a media key enabling the users to access the item of media content.

Abstract: The present disclosure proposes methods, devices, systems, and computer programs for creating a permit. In more details, the method comprising the steps of receiving a request comprising a first permit identifier, wherein the first permit identifier identifies a first permit, and obtaining a first permit data based on the first permit identifier wherein the first permit data comprises data indicative of at least one permission and wherein the at least one permission provides an indication of one or more actions a holder of the first permit can take and/or what the holder of the first permit is allowed to do, wherein the request is a request to create a further permit and the request comprises data indicative of a further permit.

Abstract: A computer implemented method of using a blockchain to coordinate data transfer over a P2P network. The method comprises obtaining a second hash value, wherein the second hash value is generated by hashing at least a data request with a first hash function to generate a first hash value and then hashing at least the first hash value with a second hash function to obtain the second hash value. The data request is associated with the target data item. A primary request transaction is submitted to a blockchain network, wherein the primary request transaction comprises the second hash value and one or more first outputs, each first output being locked to a respective public key associated with a respective P2P node connected to the requesting P2P node. The target data item is obtained from the target P2P node.

Abstract: A method of generating a blockchain transaction comprising: generating a transaction comprising a locking script comprising a first shared hash value (HV) generated by applying a hash function (HF) to a second shared HV, wherein the second shared HV is generated by applying a HF to a combination of the respective public keys, and wherein the locking script is configured to require an unlocking script to comprise a target public key, a target signature, and an intermediate HV generated based on all but one of the respective public keys, apply the HF to the target public key to generate a target HV, combine the target HV and the intermediate HV to generate a target second shared HV, apply the HF to the target second shared HV to generate a target first shared HV, an verify that the target first HV matches the first shared HV, and verify the target signature.

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 computer-implemented method of generating a respective signature share of a digital signature for signing a message, wherein the method is performed by a first participant of the group and comprises: obtaining at least the threshold number of respective participant indexes, wherein the obtained respective participant indexes comprises a first participant index associated with the first participant; generating a private key index, wherein the private key index is generated based on a hash of a combination of the obtained respective participant indexes; generating a second common private key of the first hierarchical key structure; and generating a first signature share of the digital signature.

Abstract: A method of communicating a secret between a sender and a recipient is disclosed. The method comprises sending information identifying secrets selectable by the recipient and receiving a first public key of an elliptic curve cryptography system, corresponding to a first secret selected for access by the recipient and for which a first private key is accessible to the recipient. A second public key is received, corresponding to a second secret not selected for access by the recipient, wherein a corresponding second private key is not available to the recipient. First and second secrets encrypted by means of the respective first and second public keys are sent to the recipient, wherein the first secret is accessible to the recipient by means of the first private key, the second secret is inaccessible to the recipient, and the sender is unable to distinguish between the first and second secrets.

Abstract: A computer-implemented method for enabling non-native blockchain signatures to be verified in-script, wherein the method is performed by a first party and comprises: obtaining a second blockchain transaction, wherein the second blockchain transaction references a first blockchain transaction; generating a first signature based on at least the second blockchain transaction, wherein a first private key used to generate the first signature is set equal to one; generating a second signature based on the first signature, wherein the first signature is a native blockchain signature and the second signature is a non-native blockchain signature; including the first signature and the second signature in an unlocking script of the second blockchain transaction for verification when the unlocking script is executed together with a locking script of the first blockchain transaction; and causing the second blockchain transaction to be submitted to a blockchain network.

Abstract: A method performed by a node of a blockchain network, comprising: accessing the locking script from a first transaction on the blockchain; receiving a second transaction not yet on-chain, the second transaction comprising an unlocking script; extracting from the first transaction or another transaction on the blockchain, a portion of code formulated in a second language other than a first language used for the locking and unlocking scripts; running the extracted portion of code in the second language, wherein as a result thereof the code generates at least one value; writing this value to a storage location readable by the locking script; and running the locking script together with the unlocking script in order to validate the second transaction, wherein the unlocking script is configured to read the first value from said storage location, and a condition for validation according to the locking script is dependent on the first value.

Abstract: A computer-implemented method for generating an identity-based cryptographic key, the method comprising: obtaining a set of private key shares and a set of corresponding public key shares, wherein each private key share is generated based on the personal identifier, and wherein at least one of the set of private key shares is generated by a respective one of a set of key-generating parties; generating an identity-based private key based on each of the one or more private key shares; and generating a partial identity-based public key, wherein the partial identity-based public key is generated based on each of the set of corresponding public key shares; transmitting the partial identity-based public key to at least one of the set of key-generating parties for generating the identity-based public key; and/or generating the identity-based public key, wherein the identity-based public key comprises the personal identifier and the partial identity-based public key.

Abstract: Techniques are presented relating to steps after a congress pool has accepted a request from a requester to activate a script. The steps include preparing, by a node, a blockchain transaction cryptographically locked with a public key associated with the congress pool, the blockchain transaction configured to permit a plurality of information providing systems to add inputs to the blockchain transaction; determining a centre point for data received from the plurality of information providing systems; and activating, by the node in cooperation with other nodes of the congress pool, the script based on the centre point.