I am Dmitriy Tabakov, Russian Federation.

Following text describes cryptosystem NLCS (Non-linear crypting system) developed by me and my colleagues from MercurySoftworks. I showed the idea of the algorithm on the conference on non-linear dynamics; from that point of view I get first rank diploma, but I want to know how it look from the cryptography’s position. And also I thought about an opportunity of shareware selling of program based on this cryptoalgorithm. And please excuse me for my English…

Main idea

NLC algorithm is based on the idea that was already used in radio communications security. When we want to protect radio signal, we generate noise (chaotic) signal with defined starting parameters and apply it to the source signal, and then send the result. The receiver, knowing the same parameters, generates an “antinoise” signal in resonance with the frequencies of noise signal. Then result is filtered and so source signal becomes decrypted. This encryption is very hard to break, because there no suitable algorithms for prognosis of noise signals, even if some parts of source and result signals are known. There are also different processes, which make it hard to break, for example ‘stochastic (random) resonance’, which amplify and change some parts of source signal. But in this encryption there are also problems in working, for chaotic nature of signal and receiving problems can make it undecryptable.

So the main idea of algorithm was to use this in computer technology, using mathematical procedures for creating chaos signal(for example, the simplest method is Feigenbaum bifurcation approach to chaos: x[i+1] = r • x[i] • (1.0 - x[i]), where x[0]=0.5, 0<x[i]<1, 1<r<4 which can be used to generate a chaos signal.

Algorithm- I included algorithm description in Alg.rtf file in attached archive because of Microsoft Equation formulas.

Realization

I developed program NLC, which uses this algorithm. It gives user ability to choose encryption parameters (quantity of chaotic signals, max. derivative level, etc.). Also it uses more advanced form of algorithm, for example it separates source signal to blocks and uses advanced functions to apply(for example, F(k,x)=ArcTan(k*sin((k*x)^0.5))) to signal. You can download its current version (it is in English) at http://www.nlcsystems.webhost.ru/nlcsetupfull.exe

If you are interested, please send me to mailto:mailto:dmitriyit@programmer.net

your review of algorithm and program, critics and recommendations. This is short description of algorithm, but because of translation problems it will take long time for me to translate detailed description (especially about program source code). But I will try.

Anyway, thank you for reading this.

Best Regards, Tabakov Dmitriy.