Abstract: A method for turning variable-length file path names into fixed-length object identifiers in a data repository, the method comprising, assigning a fixed-value identifier to a file system in the data repository, computing a first deterministic pseudo-random function that combines a first component of a plurality of file system pathname components associated with a file with the fixed-value identifier, computing a second determininstic pseudo-random function that combines a second component of the plurality of file system pathname components with the result of the first function, and using at least one of the computed deterministic pseudo-random functions to produce a fixed-length object identifier for the file.

Abstract: A method by which more than one client program connected to a network stores the same data item at the same location or locations in a data repository connected to the network, the method comprising having a first client program deposit a first data item in a data repository, the depositing including determining a digital fingerprint from the data item using a reproducible pseudorandom process that produces digital fingerprints having a pseudorandom distribution, storing the data item in the data repository at a location or locations associated with the digital fingerprint, and associating a deletion permission token with the data item, and storing this association in the data repository, having a second client program initiate a process for depositing a second data item in the data repository, wherein the second data item is identical to the data item stored by the first client program, the process including determining a digital fingerprint from the second data item using the reproducible pseudorandom proce

Abstract: A method by which objects that have content in common share storage in a data repository, the method comprising breaking an object into component data items at boundaries that depend upon the content of the object, determining digital fingerprints for the component data items, initiating processes to deposit a plurality of objects containing distinct occurrences of the identical component data item within their content, storing distinct information for some component data items of an object's content, but for other component data items relying on the identical component data item already stored, rather than storing a separate copy of the identical component data item.

Abstract: A method for providing naming and access control of data items in a data repository, the method comprising having a first client program deposit a data item in the data repository, the depositing including determining a digital fingerprint from the data item, and storing the data item in the data repository at a location or locations associated with the fingerprint, having the first client program specify an object name for an object that comprises a set of data items, storing in the repository an association between the name and the set of data items, and allowing the client program to retrieve a data item from the set of data items by specifying the object name and without providing the digital fingerprint of any data item or composite of data items.