The present invention is notably directed to methods, systems and computer program products for securing data operations in a computerized system comprising interconnected nodes, wherein the nodes are configured to transmit, receive and store data, and wherein the method comprises executing computerized cryptographic methods to implement two or more proofs of work that comprises: provably crawling, from each node of at least a subset of the interconnected nodes, a respective subset of data stored on nodes of the system; and provably acquiring, at each node of the subset, data in the subset of data.