Additional hash functions in content-based addressing
US7373345B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2004 |
| Grant date | May 13, 2008 |
| Priority date | — |
| Expiry date | Jun 3, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S707/99953
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A hash function used for content addressing is different from the hash function used for content verification. Adding a file to a database involves storing both hash function values in a table as pair. Verifying the integrity of a file believed to be a duplicate in a database, or when retrieving a file, makes use of the verification hash function. Files can be continuously checked. A multi-level database can be used. A second hash function can be added to an existing system. A verification hash function can be upgraded and more than one content verification hash function can be used. In a variation, a random number generator is used instead of a hash function for content addressing; the verification hash function is also used. Files addressed using a random number are added or retrieved from a database and their verification hash values are checked. Time stamps and digital signatures are used for security.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.