The present invention relates to the reliable storage of data within a distributed storage system. A method and system for storing a data unit within a distributed storage system is disclosed, wherein the distributed storage system comprises a plurality of storage elements of unspecified system reliability, a public network interconnecting the plurality of storage elements and a reliability index control unit measuring a plurality of storage element reliability indexes associated with the plurality of storage elements. The data unit is stored following the steps of receiving a request to store the data unit according to a data unit reliability index and storing replicated copies of the data unit in at least one storage element, such that the data unit reliability index is achieved.