(Message inbox:36) Received: from 198.181.231.162 by note1.nsf.gov with SMTP id AA15610 (5.65c/IDA-1.4.4 for ); Fri, 27 Jan 1995 08:39:02 -0500 X-Sender: abush@note1.nsf.gov Message-Id: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Fri, 27 Jan 1995 08:38:01 -0500 To: twilkins From: abush (Aubrey Bush) Subject: Klapper ABSTRACT Klapper, Andrew NCR9400762 University of Kentucky Research Foundation Building Tools for Secure High Volume Communication $153833 This grant will support new and continued research on pseudorandom sequences and their applications to communications systems, cryptography, and coding theory. The objective is to investigate properties of pseudorandom sequences generated by various types of nonlinear feedback shift registers. these sequences are widely used in cryptography, spread spectrum communications systems, and other communications related applications, and are closely related to error correcting codes. The first theme of the work involves the investigation of sequences generated by an exciting new class of feedback shift registers, Feedback and Carry Shift registers (FCSRs), which are based on algebra over the 2-adic numbers. These registers, recently invented by the principle investigator and his colleague Dr. Mark Goresky, are fast, simple mechanisms that can be used to generate a large class of pseudorandom sequences. They have been used to crack a certain stream cipher system, and the sequences they generate are closely related to arithmetic codes. FCSRs tie together research that has been carried ut in a variety of previously unconnected areas. They have a rich algebraic structure that parallels the algebraic structure of the widely studied m-sequences. There are many questions to be answered about these sequences, including questions of their cryptographic properties, their correlation properties, and their relation to arithmetic codes. Of special interest if the potential for generalization to sequences over arbitrary finite fields, and the application of mechanisms for nonlinearization akin to those applied to linear feedback shift registers. The second theme is the search for large families of pseudorandom sequences for use in practical secure CDMA communications systems. It appears likely that CDMA and spread spectrum will become the standard for many high volume applications. A new framework for developing sequences with low pairwise cross correlations and large linear span, developed by the principal investigator, reduces the problem to one of finding families of functions over finite fields with certain properties. ***************************************************************************** Aubrey M. Bush Program Director, Acting Deputy Divison Director Division of Networking and Communications Research and Infrastructure National Science Foundation 4201 Wilson Boulevard Arlington, VA 22230 703 306 1949 abush@nsf.gov
