A computer-implemented method comprising: Generating , by a first initiator node of a first cyclically-ordered set of nodes participating in a blockchain network, a private key; Generating , by the first initiator node, a cryptographic share of the private key for each of the nodes of the first set and distributing respective ones of the cryptographic shares to the other nodes of the first set; Determining , by the first initiator node, a first locking value based on public keys corresponding to each of the cryptographic shares; Preparing , by the first initiator node, a transaction arranged to transmit control of a resource from a source address associated with the first initiator node to a receiving address of a node immediately subsequent to the first initiator node in the first set responsive to satisfaction of an execution condition including supply of a first unlocking value corresponding to the first locking value; and initiating, by the first initiator node, preparation of further transactions to form a circuit of transactions between each pair of adjacent nodes in the first set, each of the further transactions arranged to transmit control of a respective resource from an address associated with a first node of each pair to an address associated a second node of that pair responsive to satisfaction of an execution condition including supply of a respective unlocking value corresponding to a respective locking value, wherein the second node of each pair is immediately subsequent in the first set to the first node of that pair, and wherein the respective locking value is determined based on the cryptographic share that was distributed to the first node of a given pair and a value received from a node immediately previous that node in the first set. Generating , by a first initiator node of a first cyclically-ordered set of nodes participating in a blockchain network, a private key; Generating , by the first initiator node, a cryptographic share of the private key for each of the nodes of the first set and distributing respective ones of the cryptographic shares to the other nodes of the first set; Determining , by the first initiator node, a first locking value based on public keys corresponding to each of the cryptographic shares; Preparing , by the first initiator node, a transaction arranged to transmit control of a resource from a source address associated with the first initiator node to a receiving address of a node immediately subsequent to the first initiator node in the first set responsive to satisfaction of an execution condition including supply of a first unlocking value corresponding to the first locking value; and initiating, by the first initiator node, preparation of further transactions to form a circuit of transactions between each pair of adjacent nodes in the first set, each of the further transactions arranged to transmit control of a respective resource from an address associated with a first node of each pair to an address associated a second node of that pair responsive to satisfaction of an execution condition including supply of a respective unlocking value corresponding to a respective locking value, wherein the second node of each pair is immediately subsequent in the first set to the first node of that pair, and wherein the respective locking value is determined based on the cryptographic share that was distributed to the first node of a given pair and a value received from a node immediately previous that node in the first set. <EOS>