Abstract: A computer program for generating an input and an output for a voting transaction for a blockchain for casting a vote, the computer program causes one or more processors to be configured to: receive voting instructions from a vote coordinator comprising one or more public keys and a set of voting options; render a user interface displaying the voting options; receive a user selection of one of the voting options; and generate an input-output pair for inclusion in a voting transaction; wherein a non-signature portion of the input comprises an outpoint identifying an unspent transaction output, and a signature portion of the input comprises a signature single flag and an associated signature signing at least the non-signature portion of the input-output pair and the output of the input-output pair but not any other output of the voting transaction, and the output of the input-output pair comprises one of public keys.

Abstract: A surgical robotic system includes at least one eye tracking system positioned detect the direction of at least one user's gaze. Input derived from the eye tracking system may be used to enter commands to the surgical robotic system depending on the directions of the gaze detected or other aspects of the gaze such as pupil dilation or speed of eye movement.

Abstract: A method, system and program enabling a third party to determine whether a first party and a second party agree on membership of a set of blockchain transactions transacting between the first and second party.

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: In one aspect, the present disclosure proposes methods, devices and systems for partitioning a request associated with a digital asset into an arbitrary number of transactions. The partitioning is based on knowing or obtaining a maximum number of outputs allowed for a request and an arbitrarily selection of a possible integer partition of an arbitrarily selected integer. The randomly selected integer partition then forms the basis for determining the number of transactions and UTXOs, so that a digital asset value can be arbitrarily split across the determined UTXOs before being stored on a public blockchain. In another aspect, the present disclosure proposes methods, devices and systems for arbitrarily distributing a digital asset value associated with a request across an arbitrarily determined number of transactions. This is based on an arbitrarily selected number of transactions, and a maximum number of outputs allowed for each request.

Abstract: A computer-implemented method of generating a second public key based on a first public key using blockchain transactions. The method is performed by a first party and comprises generating an output script of a first blockchain transaction. The output script comprises a public key derivation script configured to, when executed alongside an input script of a second blockchain transaction, generate the second public key based on the first public key. The input script of the second blockchain transaction comprises the first public key. The method further comprises transmitting the first blockchain transaction to one or more nodes of a blockchain network for inclusion in the blockchain.

Abstract: A computer-implemented method of generating a hash-based message authentication code, HMAC, of a message using blockchain transactions. The method is performed by a first party and comprises generating an output script of a first blockchain transaction. The output script comprises a HMAC script configured to, when executed alongside an input script of a second blockchain transaction, generate the HMAC of the message based on an input value included in the input script of the second blockchain transaction. The method further comprises causing the first blockchain transaction to be transmitted to one or more nodes of a blockchain network for inclusion in the blockchain.

Abstract: A computer-implemented method for adapting connections between nodes of a layered network. The layered network comprises a plurality of nodes arranged in an ordered set of layers. The ordered set of layers comprises, in order, a core layer comprising a set of core nodes, a second layer comprising a set of second nodes, and one or more outer layers each comprising a respective set of outer nodes. Each core node is connected to at least one other core node. The method is performed by an adapting node, the adapting node being a node of the layered network that is connected to one or more second nodes and multiple core nodes. The method comprises, based on one or more network properties of the layered network, disabling a respective connection between the adapting node and at least one but not all of the multiple core nodes.

Abstract: A computer-implemented method for connecting to a layered network. The layered network comprises a plurality of nodes arranged in an ordered set of layers. The ordered set of layers comprises, in order, a core layer comprising a set of core nodes, a second layer comprising a set of second nodes, and one or more outer layers each comprising a respective set of outer nodes. Each core node is connected to at least one other core node. The method is performed by a connecting node and comprises connecting to the network according to a connection protocol. The connection protocol requires that each node must connect to at least one node of a preceding layer, and each outer node must also connect to at least one core node.

Abstract: A method comprising, at an attesting node of a network: receiving a sequence of data items from one or more client nodes of the network, determining an order of the sequence of data items, and attesting to the order by: including an indication of a respective set of one or more of the data items in each of a series of blockchain transactions. Each successive transaction comprises a respective input pointing to an output of the respective preceding transaction, wherein the output of the respective preceding transaction comprises a locking script, and the input of the respective successive transaction includes an unlocking script comprising a respective signature based on a respective key in a series of keys. The respective signature in each successive transaction signs a portion of the respective successive transaction including at least the indication of the respective set of data items.

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 system and method allow creation of surgical annotations during surgery. A digital image of a treatment site in a region of patient anatomy is captured using a camera and is displayed on an image display. The system displays an overlay marking an anatomic region of interest in the displayed image. During the course of the surgery, panning of the image results in the anatomic region of interest being outside the displayed field of view. In response to user input, the displayed image is subsequently panned such that the anatomic region of interest and the displayed overlay return to the displayed field of view.

Abstract: A method of executing a transaction of a blockchain. The transaction comprises at least one output comprising a locking script, and the locking script comprises an instance of a first opcode and one or more instances of a second opcode. Each instance of the second opcode separates portions of the locking script. Upon calling the instance of the first opcode, a first data element is read from at least one stack, the first data element being generated during execution of the locking script with an unlocking script of a different transaction. A first part of the locking script that follows an instance of the second opcode corresponding to the first data element is output.

Abstract: Methods and devices to track proof-of-work contributions from mining devices in a mining pool. The mining pool includes a pool master computing device that stores a bloom filter. The bloom filter stores candidate block header information that meets a partial proof-of-work standard based on regular reports from the mining devices during their proof-of-work searching. On receipt of new candidate block header information form one of the mining device, the pool master constructs a candidate block header using the information and assesses whether it is already stored in the bloom filter. If not, then it stores the block header in the bloom filter. If so, then it records a bad hash in association with the mining device that reported it.

Abstract: The invention provides improved methods and corresponding systems for the sharing, storage, creation and accessing of data stored on a blockchain eg the Bitcoin blockchain. It may form part of a protocol for searching the blockchain for content/data. A method in accordance with the invention may be used for associating or linking data stored within (separate/different) blockchain transactions to enable the identification, retrieval and/or sharing of data stored therein. Additionally, or alternatively, it facilitates identification of transactions (TX) in a blockchain which store content/data that needs to be shared, transmitted, stored and/or accessed by a user. Such a method comprises the step of mapping a mnemonic to: 1) a public key (PK) associated with the transaction (TX); and 2) the transaction ID (TXID) of the transaction (TX).

Abstract: The invention provides improved methods and systems for storing, sharing retrieving, writing and accessing data (content) on a blockchain. The invention may form part of a protocol for storing, searching and accessing the data. An embodiment of the invention comprises the step of processing at least one blockchain transaction (Tx) comprising: a protocol flag; a discretionary public key (DPK); and a discretionary transaction ID (DTx ID). These are discretionary in the sense that they are not required as part of the underlying blockchain protocol but in accordance with the present invention. This combination of features enables portions of data to be identified, retrieved and shared on a blockchain, and also to be linked/associated with one another when provided in a plurality of transactions. It enables a graph or tree-like structure to be constructed, which reflects the hierarchical relationships between portions of data, facilitating their processing, searching and sharing.

Abstract: A method of executing transactions of a blockchain network. A first transaction comprises at least a first output comprising a first locking script of a stack-based scripting language, the first locking script comprising a portion of the first locking script to be executed before a first instance of an opcode is executed. A second transaction comprises a first unlocking script that references the first output in the first transaction. Upon executing the first instance of the opcode, execution of the first locking script is terminated whilst not invalidating the first transaction. A first data element is read from at least one stack, wherein the first data element is generated during execution of the first unlocking script and the portion of the first locking script. The first data element as read from the at least one stack is supplied to an off-chain function, wherein the function is configured to generate a result based on at least said first data element.

Abstract: A method of validating transactions for recordal in a blockchain comprises receiving one or more transactions at a node of a blockchain network. For each received transaction a protocol for validating the transaction is applied. The protocol is configured to allow a termination opcode to be included in an output script of the transaction. The termination opcode is configured to, upon being executed by the node, a) terminate execution of the output script, and b) not to invalidate the transaction based only on the inclusion of the termination opcode in the output script. The protocol is also configured to disallow any instance of the termination opcode from being included in an input script of the transaction, said disallowing comprising the node at least invalidating the transaction if any instance of the termination opcode is included in the input script.

Abstract: A method comprising, at a node of a blockchain network: obtaining a first transaction including runnable code specifying a reference instance of an r-part of ant ECDSA signature; receiving a second transaction including information comprising at least an s-part of the ECDSA signature, and obtaining a public key wherein the ECDSA signature signs a message based on a corresponding private key; and running the code from the first transaction, the code being configured to return a result of true, irrespective of whose private key was used as the first private key, on condition that: the ECDSA verification function, as applied to the ECDSA signature, verifies that the s-part received in the second transaction corresponds to the reference instance of the r-part specified by the first transaction, given the message received in the second transaction and the obtained first public key.

Abstract: A method comprising: a second party receiving confirmation that a first party agrees to a statement; the second party receiving a piece of information after said confirmation, and after a cryptographic signature of the first party. To attest to this, the second party generates their own cryptographic signature by signing a portion of data comprising said piece of information or a transformation thereof. A network of nodes is then sent one or more transactions comprising the first and second signatures. Transactions are propagated across the network to be recorded in a blockchain on condition of meeting a validation condition. The validation condition for one of the one or more transactions comprises: the first signature is included in one of the one or more transactions, the second signature is included in one of the one or more transactions, and the second signature was generated by signing the particular portion of data.