Dynamic encryption keys for use with XTS encryption systems employing reduced-round ciphers
US9405919B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2014 |
| Grant date | Aug 2, 2016 |
| Priority date | — |
| Expiry date | Jun 13, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/805
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
One feature pertains to encrypting data to improve data confidentiality. In one aspect, a modified form of XTS encryption is provided for use with reduced-round block ciphers. A data unit index of data to be applied to the reduced-round cipher is encrypted under a secret key to generate or otherwise obtain a modified secret key for applying to the reduced-round cipher. That is, data to be encrypted by the reduced-round cipher is not encrypted under a static key but is instead encrypted under a dynamic key that varies according to the index of the data. If an attacker were to derive the value of the key applied to the reduced-round cipher by analyzing data encrypted by the cipher, the attacker would only obtain the dynamic key corresponding to one particular data unit index, rather than a global static key applied to an entire address space. Decryption procedures are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.