Multi-level file digests
US8301896B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2010 |
| Grant date | Oct 30, 2012 |
| Priority date | — |
| Expiry date | May 7, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/60
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Multi-level file digests for electronic files are disclosed. A top level digest represents a single digest for the associated electronic file. Lower level digests represent digests for portions of the associated electronic file. The top level digest is derived from the lower level digests. The top level digest is useful for facilitating rapid comparison to determine whether electronic files are the same. In one embodiment, electronic files are encrypted with a block encryption scheme, and digests are efficiently calculated and stored on a block-by-block basis. Advantageously, when modifications to an encrypted electronic file occurs, only those modified blocks need to be processed to undergo decryption and re-encryption to determine the appropriate digest.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.