Nchain Licensing Ag

Nchain Holdings Limited

Thomas Trevethan

John Fletcher

Marco Bardoscia

Craig Steven Wright

Techniques are presented to instantiate an event chain with a first block, wherein the first block is timestamped with an instantiation time; monitor for an event associated with a monitoring request; signal to other nodes in a plurality of nodes based on the monitoring by providing a commitment to a plurality of nodes in the plurality of nodes, wherein based on occurrence of the event providing either a dummy signal or an indicator comprising an encryption private key share held by the node, wherein the commitment is provided to the other nodes in the plurality of nodes; monitor for commitments from the other nodes in the plurality of nodes, wherein each commitment comprises a dummy signal or an encryption key share; process the commitments received from the other nodes to obtain an encryption private key share; and identify the encryption private key based on the analysis of the commitments.

Controlled cryptographic private key release

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

The invention relates to efficient zero knowledge verification of composite statements that involve both arithmetic circuit satisfiability and dependent statements about the validity of public keys (key-statement proofs) simultaneously. A method is disclosed for a prover proving to a verifier that a statement is true, while keeping a witness (w) to the statement a secret, and a verifier using a reciprocal method to verify the proof. The prover sends, to the verifier, data including a statement represented by an implemented function circuit, individual wire commitments and/or a batched commitment for the function circuit of the statement, a given function circuit output, and a proving key. Based on the sent data, the verifier is able to determine satisfiability of the function circuit, calculate an elliptic curve point, and validate the statement, thus determining that the prover holds the witness to the statement and ensuring the data complies with the statement.

Computer-implemented system and method for enabling zero-knowledge proof

A method of digitally signing a message is disclosed. The method comprises distributing first shares of a first secret value among a plurality of participants, wherein the first secret value is a private key accessible by means of a first threshold number of the first shares, and is inaccessible to less than the first threshold number of the first shares; distributing second shares of a second secret value among the participants, wherein the second secret value is an ephemeral key, wherein said ephemeral key is inaccessible to less than said first threshold number of said second shares; and distributing third shares of a third secret value among the participants, wherein each third share is adapted to be applied to a message to generate a respective fourth share of a fourth secret value, wherein the fourth secret value is the message signed with the private key and using the ephemeral key.

Computer-implemented method and system for transferring access to a digital asset

A digital time-lock contract specifies that an agent holds an encryption private key corresponding to an encryption public key on a blockchain network and then releases the encryption private key to the blockchain network within a specified time window. An agent provides a first cryptographic asset for holding and then releasing the encryption private key to the blockchain network, the first cryptographic asset being transferrable when the encryption private key is released to the blockchain network within the specified time window. A client provides a second cryptographic asset to the agent for holding and then releasing the encryption private key to the blockchain network, the second cryptographic asset being transferrable when the encryption private key is released to the blockchain network within the specified time window. The digital time-lock contract can be broadcast to the blockchain network for mining onto the blockchain.

Computer-implemented system and method for time release encryption over a blockchain network

The invention relates to a method of enabling zero-knowledge proof or verification of a statement (S) for enabling exchange of data between a prover and a verifier, wherein the prover has access to first data on a first blockchain, and the verifier has access to second data on a second blockchain. In the method, a prover sends to a verifier a set of data including a statement, which for a given function circuit output and an elliptic curve point, the function circuit input is equal to the corresponding elliptic curve point multiplier. The statement can be that the prover knows a private key for an address on a blockchain network.

Computer-implemented system and method for exchange of data

The invention relates to distributed ledger technologies such as consensus-based blockchains. Computer-implemented methods for smart contract outcome determination are described. The invention is implemented using a blockchain network, which may be, for example, a Bitcoin blockchain. A set of conditions is determined between counterparties, with the set of conditions having a plurality of possible outcomes that includes a first possible outcome associated with a first distribution of a digital asset and a second possible outcome associated with a second distribution, different from the first distribution, of the digital asset. A counterparty transaction is created that includes, as output, the set of conditions encoded into computer-executable instructions and the digital asset. An outcome is received from a third party, with the outcome corresponding to the first possible outcome or the second possible outcome. An outcome transaction is created to transfer control of the digital asset of the counterparty transaction, the outcome transaction including the outcome as input. As a result of validating the outcome transaction at a node in a blockchain network, the digital asset is distributed, based at least in part on the outcome, to the counterparties in accordance with the first possible outcome or the second possible outcome.

Smart contract execution using distributed coordination

There may be provided a computer-implemented method. It may be implemented using a blockchain such as, for example, the Bitcoin blockchain. The computer-implemented method includes: i) joining a congress by transferring, by a node operating in a proof-of-work blockchain network, one or more digital assets to a congress pool having one or more other digital assets associated with other members of a congress; ii) detecting, by the node, a special transaction of digital assets on the proof-of-work blockchain network to an address associated with the congress pool, the special transaction satisfying determined criteria; and iii) minting, by the node, one or more digital assets on a proof-of-stake blockchain network in response to detecting the special transaction.

Secure transfer between blockchains

Rapid distributed consensus on blockchain

This specification describes a system and method that enables bitcoin signed transactions to be accepted as a payment for goods and services instantly and off-line, without the need to wait for confirmation that the transaction is included in a valid block, or even for confirmation that a transaction has been received by the network. Building on the concept of a one-time signature implemented within bitcoin script, this method involves a payer providing the payee with a special compensation key at the point-of-sale which can be used to claim a time-locked deposit output when combined with a 'revealed' private key, if (and only if) a double-spend is perpetrated by the payee. The validity of this compensation key is guaranteed via a novel type of zero-knowledge-proof, which is highly efficient: the proof can be generated in ˜5 milliseconds and can be verified in −30 milliseconds. The use of this system in a retail setting would allow vendors to accept instant cryptocurrency payments off-line for high value items without aggregated risk of loss, and without the need to trust a third party service.

Computer-implemented system and method suitable for increasing the security of instant off-line blockchain transactions

A computer-implemented method that may be implemented using a blockchain network including monitoring a computational task distribution system to detect a challenge to a proposer string provided by a proposer computer system in response to a request made by a requester computer system, and as a result of detecting the challenge, at least: resolving the challenge using a first blockchain network by at least selecting a solution from a set of solutions provided to the first blockchain network, the set of solutions at least including the proposer string; and distributing digital assets from the first digital asset and the second digital asset to one or more parties of the computational task distribution system based at least in part on the solution.

Provided herein is a computer-implemented method, a system, and a non-transitory computer-readable storage medium. The system may be implemented using a blockchain network. The computer-implemented method includes: i) attaching a digital asset of a first entity to an exchange platform; ii) computing a first shared key associated with the digital asset using a key of the first entity and a first key of the exchange platform; iii) generating and broadcasting a first blockchain transaction to a blockchain network; and iv) initiating, by the first entity, transfer of ownership of the digital asset from a first entity to a second entity; v) computing a second key and a second shared key; vi) replacing the first key associated with the exchange platform with the second key associated with the exchange platform; and vii) detaching, by the second entity, the deposit from the exchange platform using the second shared key.

Secure off-chain blockchain transactions

There may be provided a computer-implemented method that includes: broadcasting, by a node in a blockchain network, a transaction to transfer one or more digital assets to a public group address associated with a congress public key, the public group being associated with one or more other digital assets associated with other members of a congress; generating a private key share to be used in a threshold signature scheme in which at least a threshold of private key shares must be used to generate a valid signature through combination of partial signatures on behalf of the congress, wherein other holders of the private key shares are the other members of the congress who have joined the congress by transfer of respective digital assets to the public group address; and using the private key share to cooperatively generate a valid signature for a transaction from the public group address.

Secure re-use of private key for dynamic group of nodes

Embodiments of the invention provide enhanced security solutions which are enforced through the use of cryptographic techniques. It is suited for, but not limited to, use with blockchain technologies such as the Bitcoin blockchain. Methods and devices for generating an elliptic curve digital signature algorithm signature (r, w) are described. In one embodiment, a method includes: i) forming, by a node, a signing group with other nodes; ii) obtaining, by the node, based on a secure random number: a) a multiplicative inverse of the secure random number; and b) the first signature component, r, wherein the first signature component is determined based on the secure random number and an elliptic curve generator point; iii) determining, by the node, a partial signature based on a private secret share, the multiplicative inverse of the secure random number and the first signature component; iv) receiving, by the node, partial signatures from other nodes of the signing group; and v) generating, by the node, the second signature component, w, based on determined and received partial signatures.

Secure dynamic threshold signature scheme employing trusted hardware

A method is presented for secure determination of a solution (S) to a computational task by a pooled resource or group having a plurality of participants (P), the group operating in a trust-less, or dealer-free, system or manner. Access to a resource or reward is offered in exchange for the solution. Individuals generate their own key pair and use their public key to establish with the group an initial shared public key that they can all use to find a solution to the task. The resource or reward can be secured by the verified shared public key. Because the private keys of each participant were used in the determination of the initial shared public key that lead to the solution then participants must then collaborate to unlock the resource or reward because the corresponding shared private key can only be generated by all participants or a pre-agreed threshold of participants.

Growing community of inventors

London, United Kingdom

Thomas Trevethan