Radiotelephone installation for prepayment operation with security protection
US5301234A · kind A · utility
73Cited by
1References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1991 |
| Grant date | Apr 5, 1994 |
| Priority date | — |
| Expiry date | Oct 10, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M15/48
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
In the course of the intercommunication between the base station and the autonomous telephone set, the first means of authentication initially generates a keyword dependent on the call charge for the current service and transmits it to the autonomous telephone set. The second means of authentication then calculates the transform of the keyword by the encryption function F with the aid of the subscriber's secret key, and transmits the transform to the first means of authentication which finally checks the authenticity of the transform to totally block the intercommunication if the authenticity is not confirmed by the check.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.