Coded data transmission system
US4434322A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 23, 1981 |
| Grant date | Feb 28, 1984 |
| Priority date | — |
| Expiry date | Jul 23, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04K1/02
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A scrambler/encryption system for randomizing an information-containing data signal for transmission and for reproducing at the receiver the information-containing data signal. The information-containing data to be transmitted is applied to a modulo-two adder, the output of which is the encoded data for transmission and which is also an input of an n stage shift register. An arbitrary logic network, having a plurality of inputs each connected to a plurality of selected shift register stages, produces a particular key signal responsive to the condition of the contents of the selected shift register stages. At the receiver, the received randomized data is fed simultaneously to the input of an n stage shift register and to an input of a modulo-two adder. An identical arbitrary logic network is connected to the receiver shift register and produces the same particular key signal responsive to the same conditions in the shift register. The modulo-two adder in the receiver has as its second input the key signal. Embodiments also show the use of the scrambler/encryption circuitry in other applications, i.e., rendering tamperproof recorded information, e.g., audio recording, and checking th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.