Methods and apparatus for providing networked cryptographic devices resilient to capture
US7149311B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 7, 2002 |
| Grant date | Dec 12, 2006 |
| Priority date | — |
| Expiry date | Dec 21, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L9/3218
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Techniques are provided by which a device that performs private key operations (e.g., signatures or decryptions) in networked applications, and whose local private key is activated with, for example, a password or PIN, can be immunized to offline dictionary attacks in case the device is captured. The techniques do not assume tamper resistance of the device, but rather exploit the networked nature of the device, in that the device's private key operations are performed using a simple interaction with a remote server. This server, however, is untrusted, i.e., its compromise does not reduce the security of the device's private key unless the device is also captured, and need not have a prior relationship with the device. Techniques are also provided for supporting key disabling, by which the rightful owner of a stolen device can disable the device's private key even if the attacker already knows the user's password.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.