Data repository and method for promoting network storage of data

• US 7,356,701 B2
• Filed: 01/07/2004
• Issued: 04/08/2008
• Est. Priority Date: 02/18/2000
• Status: Expired due to Term

• Current Assignee: Red Hat, Inc. (International Business Machines Corporation)
• Original Assignee: Burnside Acquisition, LLC
• Inventors: Margolus, Norman H., Pratt, Gill A., Knight, Thomas F. Jr.
• Primary Examiner(s): Tran; Ellen
• Application Number:
  US10/752,847
• Publication Number:
  US 20040143744A1
• Time in Patent Office: 1,553 Days
• Field of Search: 713/176, 713/179, 713/190, 713/193, 713/756, 713/163, 707/2, 707/10, 707/204
• US Class Current: 713/176
• CPC Class Codes: G06F 16/137 Hash-based content-based indexing of textual data G06F16/31
• CPC Class Codes: G06F 21/10 Protecting distributed programs or content, e.g. vending or licensing of copyrighted material protection in video systems or pay television H04N7/16 ; Digital rights management [DRM]
• CPC Class Codes: G06F 21/60 Protecting data
• CPC Class Codes: G06F 21/62 Protecting access to data via a platform, e.g. using keys or access control rules
• CPC Class Codes: G06F 21/6209 to a single file or object, e.g. in a secure envelope, encrypted and accessed using a key, or with access control rules appended to the object itself
• CPC Class Codes: G06F 21/6272 by registering files or documents with a third party
• CPC Class Codes: G06F 21/64 Protecting data integrity, e.g. using checksums, certificates or signatures
• CPC Class Codes: G06F 21/645 using a third party
• CPC Class Codes: Y10S 707/959 Network
• CPC Class Codes: Y10S 707/99932 Access augmentation or optimizing
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

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 data item, determining a digital fingerprint of the data item, and storing the data item on the storage device at a location or locations associated with the digital fingerprint. In a second aspect, the method comprises determining a digital fingerprint of the data item, testing for whether the data item is already stored in the repository by comparing the digital fingerprint of the data item to the digital fingerprints of data items already in storage in the repository, and challenging a client that is attempting to deposit a data item already stored in the repository, to ascertain that the client has the full data item.

Claims

1. A method by which a plurality of clients connected to a network store the same broadcast data item on a storage device of a data repository connected to the network, wherein the broadcast data item comprises a sequence of fragments, the method comprising:

constructing a broadcast data item composed of a plurality of fragments;

broadcasting fragments of the broadcast data item to a large number of broadcast recipients that are clients of the data repository;

depositing broadcasted fragments received by the broadcast recipients into the data repository, with each depositing operation initiated by a one of the broadcast recipients, the depositing comprising;

determining a digital fingerprint of a fragment;

testing for whether the fragment is already stored in the data repository by comparing the digital fingerprint of the fragment to digital fingerprints of fragments and other data items already in storage in the data repository; and

transmitting the fragment from the one of the broadcast recipients to the data repository only if it is not already stored in the data repository;

wherein at least some of the broadcast recipients randomize the order in which they deposit broadcasted fragments into the data repository;

whereby because only one of the broadcast recipients has to transmit each of the fragments to effect storage of all of the plurality of fragments in the repository, most of the broadcast recipients are able to store the broadcast data item without individually transmitting a significant fraction of the plurality of fragments to the repository.

2. The method of claim 1 wherein the broadcast data item is digitized video and the fragments represent frames of video or groups of frames.

3. The method of claim 2 wherein a one of the broadcast recipients comprises a digital video recorder with a local storage device and after the plurality of fragments that compose the broadcast data item have been received by the one of the broadcast recipients and deposited by it into the data repository, the plurality of fragments are deleted from the local storage device and the broadcast data item remains accessible in the data repository for retrieval and use by the digital video recorder.

4. The method of claim 1 wherein a plurality of broadcast recipients fail to receive some of the broadcasted fragments, or receive some fragments with errors, and each of the plurality deposits a different erroneous version of the broadcast data item, with each only transmitting a small fraction of the plurality of fragments to the data repository.

5. The method of claim 1 wherein the large number of broadcast recipients is more than one hundred.