Method of detecting fraud concerning electronic memory cards used in telephony
US6226530A · kind A · utility
0Cited by
8References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 17, 2000 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Feb 17, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M2215/0148
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Detecting fraud involving an electronic memory card having a given operating frequency (F0) and used in a telephone set. An excitation signal (si) of variable frequency is applied to the card, and a response pattern (M) produced by the card responsive to a low frequency excitation is recorded. A determination is made that fraud is taking place when the response pattern becomes distorted at an excitation frequency that is lower than the operating frequency (F0) of the card.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.