Descrambling device
US5825888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1996 |
| Grant date | Oct 20, 1998 |
| Priority date | — |
| Expiry date | Sep 11, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/03866
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
In a packet analyzing circuit, first and second key data are detected and stored in respective first and second key data registers. First and second key generation circuits generate first and second keys from the first and second key data. An exclusive OR operation is carried out to both keys so as to generate a scrambling key. Using the scrambling key as an initial value, a random number generator generates a PN code used for scrambling, so that scrambled data is descrambled by adding the PN code to the data. The first key generation circuit, which receives a control signal CON from a timing generation circuit, is controlled by the control signal CON such that a scrambling key is generated only when the random number generator needs an initial value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.