Nchain Licensing Ag

Nchain Holdings Limited

Craig Steven Wright

Stephane Savanah

Jack Owen Davies

Wei Zhang

Stephane Vincent

Owen Vaughan

Chloe Ceren Tartan

Daniel Joseph

Patrick Motylinski

Brock Doiron

Simone Madeo

Giuseppe Destefanis

Jad Wahab

Alexander Tennyson Mackay

Silvia Bartolucci

Bassem Ammar

Thomas Trevethan

Pauline Bernat

Martin Sewell

Alexander MacKay

Gavin Allen

Alexandra Covaci

Steven Patrick Coughlan

Andrew James Mee

Pedro Jimenez-Delgado

Vera Vsevolozhsky

Dean Kramer

Ying Chan

Antoaneta Serguieva

Alex Mackay

John Fletcher

Michaella Pettit

Alessio Pagani

Katharine Molloy

A secure method for exchanging entities via a blockchain is presented. The method comprises receiving, from a user over a communications network, an invitation to perform an exchange of entities; generating a redeem script comprising metadata; hashing the redeem script to generate a redeem script hash; sending the first script and the first script hash on a distributed hash table (DHT); and generating an invitation transaction comprising an output associated with an encrypted digital asset, and a hash of a script comprising an indication of entities to be exchanged, conditions for the exchange, and a public cryptographic key associated with the user.

Blockchain-based exchange with tokenisation

Techniques are presented for a blockchain-implemented method and system of controlling use of or access to a parking space. The method comprises generating a blockchain transaction indicative of a condition on use of, or access to, the parking space, 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 to generate a partially signed signature script to partially complete the blockchain transaction; and responsive to the condition on use of or access to the parking space being satisfied, providing a second subset of the plurality of signatures to the blockchain transaction to fully complete the blockchain transaction.

Blockchain-implemented method and system

The invention provides methods and systems by which an agreed set of conditions governing transfers on a blockchain (e.g. the Bitcoin blockchain) can be generated and enforced. Advantageously, the conditions can be used to specify and influence the behaviour of another party who will be receiving the asset, by enforcing their fulfilment of an agreed set of rules. In one embodiment, a computer-implemented method comprises the step of providing, to a recipient, a representation of at least one rule (r) relating to a transfer to be conducted over a blockchain network. It also comprises the step of receiving, from a sender: a redeem script (R) which comprises the representation (r); and a script address comprising a hash (HR) of the redeem script (R). It also comprises the step of generating a hash (H) of the redeem script (R) and comparing it with the script address. If the hash (H) matches the script address, the sender can use the script address in a locking script associated with an output of a blockchain transaction (TX) safe in the knowledge that the rules (r) will be enforced in order to unlock the asset.

Computer-implemented systems and methods for controlling or enforcing performance of transfers conducted over a blockchain

A protocol is described which: (i) allows storage nodes to be rewarded for maintaining a public blockchain; and (ii) verifies the integrity of the blockchain with the help of a Proof-of-Blockchain Storage (PoBS) scheme. The protocol provides a way to cryptographically check if a data file stored on a remote server is intact using a challenge-response method. The protocol is secured against a man-in-the-middle attack. A malicious peer cannot pass the challenge to a third party which is storing the data and give back the response. The scheme is also publicly verifiable.

Computer-implemented system and method enabling secure storage of a large blockchain over a plurality of storage nodes

A challenge is input to a PUF device comprising a physically unclonable function, PUF. The device generates a corresponding response. A wallet application is instantiated to use a seed determined from the response, the instantiating comprising storing a transform of the seed or response in association with the wallet application. At a later time, a user supplies the wallet application with information demonstrating a right to use the seed, wherein the wallet application is configured so as in response to verify this information based on the transform as stored in association with the wallet application, and on condition that the information is thereby verified, to derive at least one child key from the seed. A blockchain transaction is then signed using the child key as derived by the wallet application in response to the verification.

Wallet application instantiation, keys derivation for signing blockchain transactions using a PUF device

A method () and system () of determining a common secret for two nodes (). Each node () 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 () 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.

Determining a common secret for the secure exchange of information and hierarchical, deterministic cryptographic keys

Methods and systems for registering identity of a mining node on a blockchain in a blockchain network. The methods may include creating a validity-check transaction having a first output controlled by the mining node and containing a miner identifier and propagating the validity-check transaction on the blockchain network. The methods may further include mining, by the mining node, a new block containing a generation transaction, wherein the generation transaction includes an information field that contains the miner identifier and a reference to the validity-check transaction. Another node may validate identity by receiving the miner identifier and the reference to the validity-check transaction, retrieving the validity-check transaction to confirm it contains the miner identifier, and determining that the first output is an unspent transaction output.

Methods and devices for registering and authenticating miner identity in a blockchain network

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.

Secure multiparty loss resistant storage and transfer of cryptographic keys for blockchain based systems in conjunction with a wallet management system

A method of using a tree structure overlaid on a blockchain, wherein each node of the tree is a different transaction. The method comprises: inspecting the blockchain to identify at least part of the tree structure, including identifying a target child node which includes a record of a file in the respective payload of that node, and identifying a path comprising one or more edges back through the tree structure from the target child node to the root node. The method then comprises: A) for each edge along the identified path from target child node back to root node, checking that the respective child node is signed by a key associated with the respective parent node, and B) checking that a current instance of the file matches the record included in the target child node. The current instance of the file is verified at least on condition of these checks.

File verification system and method

Techniques are presented for a computer-implemented method that may be implemented using a blockchain network. The computer-implemented method includes: monitoring a system to detect a challenge to a proposer string in response to a request, and as a result of detecting the challenge: placing a first digital asset and a second digital asset under exclusive control of a group of nodes via a public key associated with a group of nodes, wherein the first and second digital assets are configured to be released when a threshold number of members of the group of nodes generate a valid signature for the public key associated with the group of nodes; resolving the challenge using a blockchain network; and distributing, by the group of nodes, digital assets from the first digital asset and the second digital asset to one or more parties of the system based at least in part on the solution.

Blockchain for general computation

A computer-implemented method of encoding a digital contract between first and second parties of a blockchain network, the digital contract being for transferring an amount of a digital asset from the first to the second party based on a condition being fulfilled; the method comprising: obtaining a plurality of data elements, each representing a different contract condition, wherein at least one of the conditions is linked to the second party; generating a hash tree based on the data elements, wherein the hash tree comprises: i) first leaf hashes generated by hashing a respective data element, and second leaf hashes comprising at least one hash key generated by hashing a secret value known only to the trusted third party, ii) internal hashes, and iii) a root hash; and making the root hash available to the first party for inclusion in a transaction of the blockchain.

Digital contracts using blockchain transactions

A method of enabling knowledge proof in a blockchain transaction is disclosed. The method comprises sending, from a verifier to a prover, a blockchain transaction redeemable by means of data including (i) first data (y) based on a combination of an ephemeral key (r), second data (c) and a private key of a public-private key pair of a cryptography system, wherein the public key (v) is based on an integer generator raised to a first power, wherein the first power is based on the private key, and wherein knowledge of the private key is required in order to determine the ephemeral key from the first data, and (ii) third data (x) based on the integer generator raised to a second power, wherein the second power is based on the ephemeral key.

Computer implemented method and system for knowledge proof in blockchain transactions

A method of storing data on a blockchain, such as the Bitcoin blockchain, is disclosed. The method comprises generating a plurality of blockchain transactions, wherein a plurality of the blockchain transactions each store therein a respective part (<Content chunk 1>, <Content chunk 2>) of first data to be stored on the blockchain and second data (<Metanet Flag>) indicating that the parts of the first data are related to each other.

Computer implemented system and method for storing data on a blockchain

A computer implemented system and a method for providing user related data, such as reputational information, on users of a blockchain involved in transactions is detailed. The method includes an approach for evaluating fulfilment of transactions, particularly in the context of contracts, and then providing a record of that on the blockchain through reputational information. As a result, at a late time, this reputational information can be retrieved. Similar reputational information for other transactions can be retrieved and linked to the same user, for instance based on the use of a hash of the master public key for a user. Aggregate reputational information can be computed from the pieces of reputational information retrieved.

Computer-implemented system and method for generating and extracting user related data stored on a blockchain

A method of storing certified data on a blockchain is disclosed. The method comprises generating a first blockchain transaction (Tx) having a first output (Output 3) containing a first public key of a first private/public key pair, comprising a first private key and a first public key, of a cryptography system, first data related to the first public key, and a first digital signature applied, by means of a second private key of a second private/public key pair, comprising a second private key and a second public key, of a cryptography system, to the first data and to the first public key. The first blockchain transaction is broadcast to the blockchain.

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London, United Kingdom

Craig Steven Wright