Redactable document signatures
AssigneeHealthTrackRx
InventorsStuart Haber, William G. Horne, Miaomiao Zhang
Life of this patent
Estimating the term…
Abstract
In one implementation, a redactable document signature system includes an encoding engine, a reordering engine, and a signature engine. The encoding engine is to access a plurality of subdocuments of a document, to generate a plurality of commitment values from the plurality of subdocuments, and to generate a plurality of dummy values. Each dummy value is indistinguishable from a commitment value. The reordering engine is to define an order of the plurality of commitment values and the plurality of dummy values independent of an order of the subdocuments. The signature engine is to calculate a signature value for the document using the plurality of commitment values and the plurality of dummy values according to the order.
Claims16
1-15. (canceled)
A redactable document signature system, comprising:
- an encoding engine to access a plurality of subdocuments of a document,
- to generate a plurality of commitment values from the plurality of subdocuments, and
- to generate a plurality of dummy values, each dummy value indistinguishable from a commitment value;
- a reordering engine to define an order of the plurality of commitment values and the plurality of dummy values independent of an order of the subdocuments;
- a signature engine to calculate a signature value for the document using the plurality of commitment values and the plurality of dummy values according to the order;
- and
- a redaction engine to redact a subdocument from the plurality of subdocuments using a commitment value map.
A non-transitory processor-readable medium storing code representing instructions that when executed at a processor cause the processor to:
- select a plurality of subdocument pairs from subdocuments of a document;
- generate a plurality of commitment values for the document, each commitment value generated using a subdocument pair from the plurality of subdocument pairs;
- generate a plurality of dummy values for the document, each dummy value indistinguishable from each commitment value from the plurality of commitment values;
- define an order of the plurality of commitment values and the plurality of dummy values independent of an order of the subdocuments in the subdocument pair used to generate each commitment value from the plurality of commitment values;
- and
- calculate a signature value for the document using the plurality of commitment values and the plurality of dummy values according to the order;
- and
- redact a subdocument from the plurality of subdocuments using a commitment value map.
A document redaction method, comprising:
- identifying, using an commitment value map for a document, a position in an order for a first plurality of commitment values and a plurality of dummy values for each commitment value from a second plurality of commitment values associated with a subdocument identified for redaction from the document, the second plurality of commitment values included in the first plurality of commitment values;
- redacting a subdocument from the plurality of subdocuments using the commitment value map;
- updating the commitment value map to remove, from the commitment value map, each entry associated with the subdocument identified for redaction from the document;
- and
- inserting, based on the identifying, intermediate hash values derived from each commitment value from the second plurality of commitment values into a set of intermediate hash values for the document.
Dependencies are inferred from the claim text.