Data encryption by nonlinear transfer function
US7672453B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 21, 2000 |
| Grant date | Mar 2, 2010 |
| Priority date | — |
| Expiry date | Apr 2, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/34
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A communication system includes an encryptor and a decryptor. For improved encryption security, the encryptor includes a multitap delay line to produce mutually delayed samples of the signal to be encrypted. Each sample is operated on by a key or function to produce modified signal samples, and the modified signal samples are summed or combined to produce the encrypted signal. According to one aspect of the invention, at least one of the keys or functions includes a nonlinear function. In some embodiments, the functions are time-variant for improved security. Decryption is accomplished in some embodiments by an equalizer. The preferred equalizer is the maximum-likelihood-sequence estimators matched to the encryption functions. A Viterbi algorithm makes it easy to implement the matched equalizer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.