Custom blockchain for iot devices

A blockchain verification system for verifying a transaction in a blockchain network, the blockchain network comprising nodes participating in performing the transaction, the blockchain verification system comprising:

• a plurality of clusters, each cluster comprising a plurality of nodes of the blockchain network;
• at least one cluster, of the plurality of clusters, comprising:
• a determination unit adapted for determining, for each node of the at least one cluster, performance parameter values;
• a calculation unit adapted for calculating, for each node of the at least one cluster, a weighted sum of the determined performance parameter values;
• a designation unit adapted for designating a node, of the at least one cluster, with a highest weighted sum as a cluster leader, wherein the designation unit is also adapted for designating a number of nodes, of the at least one cluster, whose weighted sum is less than the highest weighted sum, as sub-cluster leaders, the number of nodes being at least half of a total number of nodes within the at least one cluster;
• and
• a verification unit adapted for verifying the transaction for the at least one cluster by the cluster leader and said sub-cluster leaders.

A computer program product for verifying a transaction in a blockchain network, the blockchain network comprising nodes participating in performing the transaction, the computer program product comprising:

• one or more computer-readable tangible storage devices and program instructions stored on at least one of the one or more computer-readable tangible storage devices, the program instructions comprising:
• program instructions to group the nodes of the blockchain network into a plurality of clusters of nodes;
• for at least one cluster within the plurality of clusters of nodes:
• program instructions to determine, for each node within the at least one cluster, performance parameter values;
• program instructions to calculate, for each node within the at least one cluster, a weighted sum of the determined performance parameter values;
• program instructions to designate a node, of the at least one cluster, with a highest weighted sum as a cluster leader,
• program instructions to designate a number of nodes, of the at least one cluster, whose weighted sum is less than the highest weighted sum, as sub-cluster leaders, the number of nodes being at least half of the total number of nodes within the at least cluster;
• and
• program instructions to verify the transaction for the at least one cluster by the cluster leader and the sub-cluster leaders.