In general, the invention features methods by which more than one client program connected to a network stores the same data item on a storage device of a data repository connected to the network. In one aspect, the method comprises encrypting the data item using a key derived from the content of the...http://www.google.cl/patents/US7356701?utm_source=gb-gplus-sharePatent US7356701 - Data repository and method for promoting network storage of data
