Abstract: A method of managing an overlay network overlaid on data-storage transactions of a blockchain, whereby data content of the overlay network is stored in payloads of the data-storage transactions and overlay-layer links are defined between the data-storage transactions. The method comprises identifying a graph structure of the overlay network, wherein nodes corresponds to different ones of the data-storage transactions and edges correspond to the links. Each node is associated with a respective first key for signing an input of a child data-storage transaction to authorise writing the child to the blockchain. The method further comprises using a child key derivation, CKD, function to determine a hierarchical set of second keys having the same graph structure as the overlay network, wherein the second keys enable an additional function other than signing inputs of the data-storage transactions.

Abstract: The invention provides a method and corresponding system for controlling a blockchain transaction output and/or specifying the recipient of the output. It also provides a method of controlling and/or generating an electronic communication. The invention is a blockchain-implemented solution, which may or may not be the Bitcoin blockchain. In a preferred embodiment of the invention, the method may comprise the step of sending an electronic notification to a notification address which is provided as metadata within an unlocking script of an input of a transaction (Txi) on a blockchain. The unlocking script is provided in order to spend an output from a further transaction (Tx2) on the blockchain. The input of the transaction (Txi) and/or the output of the further transaction (Tx2) may be associated with a tokenised asset represented on, or referenced via, the blockchain.

Abstract: A computer-implemented method of using blockchain transactions to issue one or more single-uses tokens for use by one or more respective token redeemers, wherein the method is performed by a token issuer and comprises: generating a token transaction, wherein the token transaction comprises: one or more token outputs, wherein each token output comprises token data representing a respective single-use token, wherein each single-use token is associated with a respective spendable output of the token transaction, and wherein a respective validity of each single-use token is conditional on the respective spendable output being present in an unspent transaction output set of a blockchain; and one or more inputs, wherein at least a first one of the inputs comprises a signature linked to a first public key of the token issuer; and transmitting the token transaction to one or more nodes of a blockchain network to be recorded in the blockchain.

Abstract: A computer-implemented method of pseudo-randomly selecting game elements for use in playing a game. An oracle obtains: a set of seed data items, the set of seed data items comprises one or more user seed data items generated by a respective user; a sequence of public keys; and a list of game elements. A total number of public keys corresponds to a total number of game elements. The oracle generates a first output of a game transaction. The first output comprises the sequence of public keys and a script configured to generate at least one pseudorandom number based on the set of seed data items. The script is configured to generate a list of the public keys based on the at least one pseudorandom number. An order of public keys in the list of public keys differs compared to an order of public keys in the sequence of public keys.

Abstract: A data structure embodied in one or more blockchain transactions has a plurality of nodes, each node embodied as a hash value contained in a blockchain transaction of the one or more blockchain transactions; and a plurality of directional edges plurality of nodes comprises leaf nodes and non-leaf nodes. In a first aspect, at least one of the non-leaf nodes has at least one child leaf node and at least one child non-leaf node, the hash value of the at least one non-leaf node being a hash of a concatenation of the respective hash values of the child leaf node and the child non-leaf node. In a second aspect, a first of the non-leaf nodes has a different number of child nodes than a second of the non-leaf nodes. In a third aspect, a first of the leaf nodes has a different level than a second of the leaf nodes.

Abstract: A method and devices for securely and privately generating a threshold vault address and distributed individual key shares reliant upon individually selected polynomial functions, without revealing the key shares and without ever reconstructing the private key. A digital asset stored at the threshold vault address may be used as an input to a transaction through generating a digital signature corresponding to the threshold vault address. Methods and devices are described for collaboratively generating the digital signature without reconstructing the private key or revealing individual key shares. Methods and devices are described for refreshing the distributed private key shares.

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 public key may be recorded on the blockchain by a certificate authority in such a manner that any third party may quickly and easily verify that the public key is certified by the certificate authority and that the certification has not been revoked. The certificate authority may be able to revoke the certification nearly instantaneously, and/or may be able to simultaneously certify a new key for the same entity while revoking the old key. The verification may be incorporated into a new transaction so that there is no gap between reliance on the certificate and the verification of its validity. In some cases, each transaction in which the certificate is used may also serve as linked certificate transaction that renews the certificate to enable a subsequent use.

Abstract: A blockchain payment channel is effected based on a series of spending transactions exchanged between parties, in which each transaction of the series of spending transactions has a future lock time, before which it cannot be committed to the blockchain, and comprises at least two spendable transaction outputs having respective digital asset values. At computer equipment of the party, a previous transaction of the series of spending transactions is received, and a function is applied to one or more function variables contained in the previous transaction to at least partially determine the current transaction. A portion of the current transaction is cryptographically signed, the signed portion comprising the at least two spendable transaction outputs, using a private key counterpart to the public key of the party, thereby computing a transaction signature for inclusion in the transaction input of the current transaction.

Abstract: A computer-implemented method of pseudo-randomly generating winning game elements for use in playing a game. An oracle obtains: a set of seed data items, the set of seed data items comprising one or more user seed data items; and a sequence of first public keys, each first public key representing a respective one of the set of first game elements. The oracle generates an output of a game transaction that comprises an output script. The script comprises the sequence of at least some of the first public keys, and wherein the output script is configured to, when executed, generate at least one pseudorandom number, the pseudorandom number being based on the set of seed data items, and to select a winning key, the winning public key being the public key at a position in the sequence of first public keys corresponding to the pseudorandom number.

Abstract: A computer-implemented method of generating a transaction associated with a blockchain, the transaction being for distributing amounts of an allocation of a digital asset, wherein the allocating party is associated with an allocating public key linked with the allocation, and wherein each recipient party is associated with a respective ownership public key. The method comprises obtaining a respective ownership public key of each of the one or more recipient parties. For each of the one or more recipient parties, a respective payment public key is generated based on (i) the ownership public key associated with that recipient user, and (ii) the allocating public key. The transaction comprises one or more output scripts, each output script configured to transfer a respective amount of the allocation to a respective payment address, the respective payment address being based on the respective payment public key.

Abstract: A blockchain payment channel based on a series of spending transactions exchanged between parties, in which: a funding transaction, committed to a blockchain, comprises at least one spendable transaction output locked to at least two public keys of the parties, wherein the funding transaction contains or otherwise evidences a function for at least partially computing the series of spending transactions. A previous transaction of the series is received at computer equipment of one of the parties. The function contained or otherwise evidenced in the funding transaction is used to at least partially compute the current transaction. A portion of the current transaction is cryptographically signed by the party, the signed portion comprising the at least two spendable transaction outputs, using a private key counterpart to the public key of the party, thereby computing a transaction signature for inclusion in the transaction input of the current transaction.

Abstract: Contributions to a work by contributors having respective levels in a defined hierarchy are recorded in one or more blockchain transactions. One or more lower-level contributors provide, to a higher-level contributor, one or more lower-level contributions respectively, and the higher-level contributor provides a higher-level contribution responsive to the one or more lower-level contributions. A higher-level contributor transaction comprises one or more inputs, which in turn comprise: one or more pointers to one or more spendable outputs of one or more lower-level contributor transactions and one or more transaction signatures. The transactions contain contributions commitments which, together with the one or more pointers, represent the relationship between the higher-level contributor and the lower-level contributors within the defined hierarchy. The one or more transaction signatures prove that relationship.

Abstract: The present disclosure relates to highly secure, high speed encryption methodologies suitable for applications such as media streaming, streamed virtual private network (VPN) services, large file transfers and the like. For example, encryption methodologies as described herein can provide stream ciphers for streaming data from, for example, a media service provider to a plurality of users. Certain configurations provide wire speed single use encryption. The methodologies as described herein are suited for use with blockchain (e.g. Bitcoin) technologies.

Abstract: A method of providing credentials to enable a second party to verify an identity of a first party. The first party is associated with a first public key which is registered with a third party. One or more first credentials are provided to the second party. A request transaction is obtained, which comprises a) an input comprising a signature generated based on a respective private key of the third party, and b) an output locked to a second public key of the first party. The second public key is based on the first public key. A confirmation transaction is generated. The confirmation transaction comprises an input that references the output of the request transaction, and a signature generated based on a private key corresponding to the second public key of the first party. The confirmation transaction is transmitted to nodes of a blockchain network for inclusion in a blockchain.

Abstract: A computer-implemented method for granting permission to a requestor to join a first network. The first network comprises a set of bridging nodes and a set of devices controllable by one or more of the set of bridging nodes. Each bridging node is also a respective node of a blockchain network. The method is performed by a registration authority and comprises generating a first blockchain transaction. The first blockchain transaction comprises an input comprising a signature linked to a first public key of the registration authority. The first blockchain transaction also comprises a first output comprising a first certificate, the first certificate comprising an identifier assigned to the requestor. The method further comprises transmitting the first blockchain transaction to the blockchain network for inclusion in the blockchain.

Abstract: A computer-implemented method for controlling one or more devices of a first network. The first network comprises a set of bridging nodes and a set of devices controllable by one or more of the set of bridging nodes. Each bridging node is also a node of a blockchain network, and each device has a respective device identifier. The method is performed by a first one of the bridging nodes and comprises generating a first blockchain transaction. The first blockchain transaction comprises a first input comprising a signature linked to a first public key of the first node, and a first output comprising command data. The command data comprises a respective identifier of a first one of the devices controlled by a second one of the bridging nodes, and a command message for controlling the first device.

Abstract: There may be provided a computer-implemented method. It may be implemented using a blockchain network such as, for example, the Bitcoin network.

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.