A method, performed by a node in a computer network including a plurality of nodes, each node having a node identifier, the method comprising: a) receiving (S510), by the node, node identifiers from other nodes of the plurality of nodes in the computer network; b) determining (S520), by the node, 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) the method further comprising: i) generating (S531), by the node, a random string; ii) performing (S532), by the node, 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 determined, by the node, to be acceptable(S533), then broadcasting (S534), by the node, 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 (S536), the node is elected (S537) to a subcommittee for the node committee, wherein the subcommittee updates the sampler graph; and d) repeating (S550) steps b) and c) until a leader committee is determined by the node, wherein the node determines (S560) the leader committee in response to determining that the respective sampler graph contains a number of nodes that is less than or equal to a predefined threshold. a) receiving (S510), by the node, node identifiers from other nodes of the plurality of nodes in the computer network; b) determining (S520), by the node, 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) the method further comprising: i) generating (S531), by the node, a random string; ii) performing (S532), by the node, 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 determined, by the node, to be acceptable(S533), then broadcasting (S534), by the node, 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 (S536), the node is elected (S537) to a subcommittee for the node committee, wherein the subcommittee updates the sampler graph; and i) generating (S531), by the node, a random string; ii) performing (S532), by the node, 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 determined, by the node, to be acceptable(S533), then broadcasting (S534), by the node, 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 (S536), the node is elected (S537) to a subcommittee for the node committee, wherein the subcommittee updates the sampler graph; and d) repeating (S550) steps b) and c) until a leader committee is determined by the node, wherein the node determines (S560) the leader committee in response to determining that the respective sampler graph contains a number of nodes that is less than or equal to a predefined threshold. <EOS>