The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 02, 2010
Filed:
Aug. 21, 2000
David William Matolak, Athens, OH (US);
David William Matolak, Athens, OH (US);
Lockheed Martin Corporation, Bethesda, MD (US);
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.