Detecting redirection during data transmission
US6960981B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 6, 2002 |
| Grant date | Nov 1, 2005 |
| Priority date | — |
| Expiry date | Oct 27, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07C2009/00793
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a method of detecting redirection or interception during a bi-directional non-contact making data transmission, the attenuation (A1) of the amplitude over the forward path is compared with the attenuation (A2) of the amplitude over the return path. The attenuation (A1) over the forward path is transmitted in encoded form with the reply signal. If the attenuation values determined thereby are of the same magnitude, then the likelihood of a redirecting process can be excluded. In order to additionally increase the security of the system, the carrier frequency (F2) of the interrogation signal can also be compared with the carrier frequency (F21) of the reply signal. The signals can also incorporate an ID code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.