Stream ciphering technique
US10469247B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2014 |
| Grant date | Nov 5, 2019 |
| Priority date | — |
| Expiry date | Oct 29, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/125
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A technique for generating a keystream (128) for ciphering or deciphering a data stream (122) is provided. As to a method aspect of the technique, a nonlinear feedback shift register, NLFSR (112), including n register stages implemented in a Galois configuration is operated. At least one register stage of the implemented n register stages is representable by at least one register stage of a linear feedback shift register, LFSR. A first subset of the implemented n register stages is representable by a second subset of a second NLFSR. A number of register stages receiving a nonlinear feedback in the second NLFSR is greater than one and less than a number of register stages receiving a nonlinear feedback in the implemented NLFSR. The keystream (128) is outputted from a nonlinear output function (118). An input of the nonlinear output function (118) is coupled to at least two of the implemented n register stages of the NLFSR (112).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.