Abstract: Embodiments of the present disclosure provides protocols, methods and systems which provides advantages such as the resistance of centralisation of mining on a blockchain network, preferably a Proof-of-Work blockchain. A method in accordance with an embodiment may comprise generating a plurality of non-parallelisable challenges (or “puzzles”) and allocating one of said plurality of challenges to each miner on the network. The miner uses an inherently sequential (non-parallelisable) algorithm to find a solution to his allocated challenge. The challenges are generated by a committee of nodes, and a new set of challenges is generated for each block.

Abstract: A method of storing certified data on a blockchain is disclosed. The method comprises generating a first blockchain transaction (Tx1) 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.

Abstract: 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.

Abstract: Embodiments of the present disclosure provides protocols, methods and systems which provides advantages such as the resistance of centralisation of mining on a blockchain network, preferably a Proof-of-Work blockchain. A method in accordance with an embodiment may comprise generating a plurality of non-parallelisable challenges (or “puzzles”) and allocating one of said plurality of challenges to each miner on the network. The miner uses an inherently sequential (non-parallelisable) algorithm to find a solution to his allocated challenge. The challenges are generated by a committee of nodes, and a new set of challenges is generated for each block.

Abstract: The present disclosure provides methods and systems for ensuring the security of a blockchain and associated network, and for enabling the establishment of consensus regarding the state of the blockchain. A method of the disclosure may be implemented by one or more nodes on a blockchain network, using a non-parallelisable algorithm to calculate an output based on a computational difficulty parameter, a hash of at least one blockchain transaction; and/or a hash of at least one blockchain block header. The non-parallelisable, inherently sequential algorithm comprises at least one of the following operations or a combination thereof: a recursive operation, a modular exponentiation and/or a repeated squaring operation.

Abstract: The invention provides improved verification solutions for blockchain-implemented transfers. It is suited for, but not limited to, implementation in an SPV wallet. In accordance with one embodiment, a system or resource is provided which comprises a plurality of novel SPV verification components, the activities of which are coordinated by a coordination component. The system enables Bob to send Alice a payment transaction template (template Tx3) and requests: the full transaction data for all input transactions (Tx1, Tx2) comprising at least one output that Alice wants to spend as inputs to a transfer (Tx3); the Merkle path for all input transactions (Tx1, Tx2) linking them to their respective Merkle roots associated with their respective block headers; the completed transfer transaction (Tx3). Alice provides this information plus her signature.

Abstract: The invention provides improved verification solutions for blockchain-implemented transfers. It is suited for, but not limited to, implementation in an SPV wallet. In accordance with one embodiment, a method, system or resource is provided which enables Alice to transfer an asset eg cryptocurrency or token to Bob across a blockchain. Alice stores complete transaction data relating to at least one blockchain transaction; and the complete Merkle path of the at least one blockchain transaction. This enables her to send Bob the full transaction data for all input transactions (eg Tx1, Tx2) comprising at least one output that she wants to spend as inputs to a transfer (eg Tx3); the Merkle path for all input transactions (Tx1, Tx2) linking them to their respective Merkle roots associated with their respective block headers; a transfer transaction (Tx3). Alice also provides her signature.

Abstract: The invention provides improved Simplified Payment Verification (SPV) solutions for blockchain-implemented transfers. It is suited for, but not limited to, implementation in one or more SPV wallets, or on smart cards etc. In accordance with one embodiment, a method, system or resource(s) is provided which enables Alice to transfer an asset to Bob. Bob sends Alice a payment transaction template (template Tx3) and requests: the full transaction data for all input transactions (Tx1, Tx2) comprising at least one output that Alice wants to spend as inputs to a transfer (Tx3); the Merkle path for all input transactions (Tx1, Tx2) linking them to their respective Merkle roots associated with their respective block headers; the completed transfer transaction (Tx3). Alice provides this information plus her signature and optionally a change address.

Abstract: The invention provides improved verification solutions for blockchain-implemented transfers. It is suited for, but not limited to, implementation in an SPV wallet. In accordance with one embodiment, a method, system or resource is provided in which Bob verifies a Merkle proof for a first transaction and, upon successful verification, submits a second transaction to the blockchain. The second transaction has an input that spends an output (UTXO) from the first transaction. Generally, the invention provides an arrangement in which Bob sends Alice a payment transaction template (template Tx3) and requests: the full transaction data for all input transactions (Tx1, Tx2) comprising at least one output that Alice wants to spend as inputs to a transfer (Tx3); the Merkle path for all input transactions (Tx1, Tx2) linking them to their respective Merkle roots associated with their respective block headers; the completed transfer transaction (Tx3).

Abstract: The invention provides improved verification solutions for blockchain-implemented transfers. It is suited for, but not limited to, implementation in an SPV wallet. In accordance with one embodiment, a method, system or resource is provided in which Bob verifies a Merkle proof for a first transaction and, upon successful verification, submits a second transaction to the blockchain. The second transaction has an input that spends an output (UTXO) from the first transaction. Generally, the invention provides an arrangement in which Bob sends Alice a payment transaction template (template Tx3) and requests: the full transaction data for all input transactions (Tx1, Tx2) comprising at least one output that Alice wants to spend as inputs to a transfer (Tx3); the Merkle path for all input transactions (Tx1, Tx2) linking them to their respective Merkle roots associated with their respective block headers; the completed transfer transaction (Tx3).