A New Concept of Key Agreement Using Chaos-Synchronization Based Parameter Estimation
Search for a key agreement algorithm not based on traditional number theoretic problem is a challenging area of research in information security. In this paper we present a new concept of key agreement, using synchronization based parameter estimation of
- PDF / 382,208 Bytes
- 4 Pages / 430 x 660 pts Page_size
- 89 Downloads / 196 Views
Abstract. Search for a key agreement algorithm not based on traditional number theoretic problem is a challenging area of research in information security. In this paper we present a new concept of key agreement, using synchronization based parameter estimation of two chaotic systems. In this short paper, we only introduce the concept, which shows promise of a new mechanism. Keywords: Key Agreement Algorithms, Chaotic Synchronization, Parameter Estimation.
1
Introduction
Designing a secure key exchange mechanism is an important and challenging research problem in information security. The security of almost all currently used methods are based on the computationally unbreakable mathematical functions of number theory. Recently proposals like Neural Cryptography [1] have introduced new concept of key exchange, the security of which does not depend on number theory. In this paper, we propose another such mechanism of non-number theoretic key exchange by public discussion.
2
Chaotic Synchronization and Key Agreement
Synchronization of two identical chaotic systems by exchanging only a subset of time dependent information is not new [2]. This can be explained by using a three parameter Lorenz attractor[3] at the transmitter (x) and the receiver (y). x˙ 1 = σt (x2 − x1 ) y˙ 1 = σr (y2 − y1 ) − k(y1 − x1 ) . x˙ 2 = ρt x1 − x2 − x1 x3 y˙ 2 = ρr y1 − y2 − y1 y3 . x˙ 3 = x1 x2 − βt x3 y˙ 3 = y1 y2 − βr y3 .
(1)
This system behaves chaotically, for some values of σ, ρ and β. Two identical chaotic systems (σt = σr , ρt = ρr and βt = βr ) starting from two different initial conditions can be synchronized by transmission of one of the time P. McDaniel and S.K. Gupta (Eds.): ICISS 2007, LNCS 4812, pp. 263–266, 2007. c Springer-Verlag Berlin Heidelberg 2007
264
G.K. Patra, V. Anil Kumar, and R.P. Thangavelu
dependent variable (like x1 ) from the transmitter to the receiver in a masterslave mode. Recently new mechanisms like mutual interaction and alternately switched bi-directional coupling [4,5] has been proposed to achieve better security in applications like secure communications. Parameter estimation methods, which can estimate all the parameters of a chaotic system are potential threats to these communication systems based on chaotic synchronization. In contradiction we will uses these parameter estimation methods as a new mechanism for key exchange. In a typical synchronization scenario identical systems are ensured by exchanging σ, ρ and β (the keys) values using some alternate method of key exchange. Here, we will consider two chaotic systems, which have the same functional structure, possessing different parameter values. We will define a mechanism by which the two chaotic systems in addition to synchronizing their time dependent values will also converge in their parameter values. Let us consider the system x˙ = f (x, p) at the transmitter and y˙ = f (y, q) at the receiver end. Here x and y are the time dependent variables, while p and q are the private parameters of the transmitter and receiver respectively.
Data Loading...
