History preservation in a computer storage system
First Claim
1. A method by which a plurality of client programs connected to a network are allowed to deposit data items identical to ones already stored in a data repository connected to the network without transmitting the full data items but are prevented from depositing data items they do not possess, the method comprising:
- depositing a plurality of data items over the network into the data repository, in response to requests from the plurality of client programs;
depositing some of the plurality of data items that are identical to data items already stored in the data repository without transmitting the full data items, using digital fingerprints to identify identical data items;
requiring clients depositing data items without transmitting the full data items to respond to challenges designed to prevent clients from depositing data items they do not possess;
determining a digital fingerprint of a data item;
testing for whether a copy of the data item is already stored in the data repository by comparing the digital fingerprint of the data item to the digital fingerprints of data items already in storage in the data repository;
challenging a client that is attempting to deposit the data item without transmitting the full data item to the data repository; and
assigning an expiration time to the data item, before which time both modification and deletion are prohibited;
wherein depositing the data item comprises ensuring that a copy of the data item is stored in the data repository and arranging for the client to have future access to read the copy;
wherein the testing step reveals that a copy of the data item is already stored in the data repository;
wherein challenging comprises requiring of the client that it supply additional information representative of the content of the data item other than the digital fingerprint;
wherein the additional information representative of the content of the data item is not sufficient to reconstruct the entire data item;
wherein challenging comprises requiring that the client provide correct answers to questions about the content of portions of the data item, or questions that require knowledge of this content; and
wherein the challenging step prevents clients that possess the digital fingerprint of the data item but not the entire data item from successfully depositing the data item and being granted future access to the copy of the data item stored in the data repository.
4 Assignments
0 Petitions
Accused Products
Abstract
A method by which a disk-based distributed data storage system is organized for protecting historical records of stored data entities. The method comprises recording distinct states of an entity, corresponding to different moments of time, as separate entity versions coexisting within the distributed data storage system, and assigning expiration times to the entity versions independently within each of a plurality of storage sites according to a shared set of rules, before which times deletion is prohibited.
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Citations
12 Claims
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1. A method by which a plurality of client programs connected to a network are allowed to deposit data items identical to ones already stored in a data repository connected to the network without transmitting the full data items but are prevented from depositing data items they do not possess, the method comprising:
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depositing a plurality of data items over the network into the data repository, in response to requests from the plurality of client programs; depositing some of the plurality of data items that are identical to data items already stored in the data repository without transmitting the full data items, using digital fingerprints to identify identical data items; requiring clients depositing data items without transmitting the full data items to respond to challenges designed to prevent clients from depositing data items they do not possess; determining a digital fingerprint of a data item; testing for whether a copy of the data item is already stored in the data repository by comparing the digital fingerprint of the data item to the digital fingerprints of data items already in storage in the data repository; challenging a client that is attempting to deposit the data item without transmitting the full data item to the data repository; and assigning an expiration time to the data item, before which time both modification and deletion are prohibited; wherein depositing the data item comprises ensuring that a copy of the data item is stored in the data repository and arranging for the client to have future access to read the copy; wherein the testing step reveals that a copy of the data item is already stored in the data repository; wherein challenging comprises requiring of the client that it supply additional information representative of the content of the data item other than the digital fingerprint; wherein the additional information representative of the content of the data item is not sufficient to reconstruct the entire data item; wherein challenging comprises requiring that the client provide correct answers to questions about the content of portions of the data item, or questions that require knowledge of this content; and wherein the challenging step prevents clients that possess the digital fingerprint of the data item but not the entire data item from successfully depositing the data item and being granted future access to the copy of the data item stored in the data repository. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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Specification