A method includes: a) receiving node identifiers from nodes of a plurality of nodes in a computer network; b) determining a plurality of node committees in a sampler graph comprising a plurality of nodes, wherein the node is present in a node committee in the plurality of node committees; c) and i) generating a random string; ii) performing a proof of work process using the random string and a hash function; iii) if the proof of work process yields a solution that is acceptable, then broadcasting the solution to all other nodes in the plurality of nodes, wherein the other nodes verify the solution; and iv) if the other nodes verify the solution, the node is elected to a subcommittee for the node committee, wherein the subcommittee updates the sampler graph; and d) repeating steps b) and c) until a leader committee is determined.