On-disk file format for a serverless distributed file system
US7401220B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2004 |
| Grant date | Jul 15, 2008 |
| Priority date | — |
| Expiry date | May 22, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/60
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A file format for a serverless distributed file system is composed of two parts: a primary data stream and a metadata stream. The data stream contains a file that is divided into multiple blocks. Each block is encrypted using a hash of the block as the encryption key. The metadata stream contains a header, a structure for indexing the encrypted blocks in the primary data stream, and some user information. The indexing structure defines leaf nodes for each of the blocks. Each leaf node consists of an access value used for decryption of the associated block and a verification value used to verify the encrypted block independently of other blocks. In one implementation, the access value is formed by hashing the file block and encrypting the resultant hash value using a randomly generated key. The key is then encrypted using the user's key as the encryption key. The verification value is formed by hashing the associated encrypted block using a one-way hash function. The file format supports verification of individual file blocks without knowledge of the randomly generated key or any user keys. To verify a block of the file, the file system traverses the tree to the appropriate leaf nod…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.