Method and apparatus for differential, bandwidth-efficient and storage-efficient backups

A method comprising:

• requesting one of at least one content-derived signature contour and at least one optimized content-derived signature contour, the content-derived signature contour including one of a plurality of content identifiers and at least one content-derived signature contour, and the optimized content-derived signature contour is derived from contour-related data and one of the at least one content-derived signature contour and a derivation from the at least one content-derived signature contour;
• determining if one of the at least one content-derived signature
• contour and the at least one optimized content-derived signature contour is present on at least one device;
• dynamically creating one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour if it is determined that one of the at least one content-derived signature
• contour and the at least one optimized content-derived signature contour is not present on the at least one device,
• returning one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour if one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour is determined to be present on the at least one device;
• and
• transmitting client contour identifications (CCIDs).

An apparatus comprising a machine-readable medium containing instructions which, when executed by a machine, cause the machine to perform operations comprising:

• determining contour requirements from a plurality of factors,
• based on the plurality of factors, one of:
• generating at least one content-derived signature contour from one of a plurality of content identifiers and at least one content-derived signature contour, and
• generating at least one optimized content-derived signature contour from contour-related data and one of said at least one content-derived signature contour and a derivation from said at least one content-derived signature contour.

An apparatus comprising a machine-readable medium containing instructions which, when executed by a machine, cause the machine to perform operations comprising:

• requesting one of at least one content-derived signature contour and at least one optimized content-derived signature contour, the content-derived signature contour including one of a plurality of content identifiers and at least one content-derived signature contour, and the optimized content-derived signature contour is derived from contour-related data and one of the at least one content-derived signature contour and a derivation from the at least one content-derived signature contour;
• determining if one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour is present on at least one device,
• dynamically creating one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour if it is determined that one of the at least one content-derived signature
• contour and the at least one optimized content-derived signature contour is not present on the at least one device, and
• returning one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour if one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour is determined to be present on the at least one device.

A system comprising:

• a plurality of devices coupled to a transmission medium, each of the plurality of devices coupled with a first process and a second process and having one of at least one content-derived signature contour and the at least one optimized content-derived signature contour,
• wherein the first process:
• determines contour requirements from a plurality of factors,
• based on the plurality of factors, one of:
• generates at least one content-derived signature contour from one of a plurality of content identifiers and at least one content-derived signature contour, and
• generates at least one optimized content-derived signature contour from contour-related data and one of said at least one content-derived signature contour and a derivation from said at least one content-derived signature contour;
• and
• stores one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour, and
• wherein the second process:
• requests one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour, the content-derived signature contour including one of a plurality of content identifiers and at least one content-derived signature contour, and the optimized content-derived signature contour is derived from contour-related data and one of the at least one content-derived signature contour and a derivation from the at least one content-derived signature contour;
• determines if one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour is present on at least one device,
• dynamically creating one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour if it is determined that one of the at least one content-derived signature
• contour and the at least one optimized content-derived signature contour is not present on the at least one device
• returns one of the at least one content-derived signature contour and the at least one optimized content-derived signature contour.