1,158 research outputs found
Attacking the combination generator
We present one of the most efficient attacks against the combination
generator. This attack is inherent to this system as its only assumption is
that the filtering function has a good autocorrelation. This is usually the
case if the system is designed to be resistant to other kinds of attacks. We
use only classical tools, namely vectorial correlation, weight 4 multiples and
Walsh transform
A Pseudo Random Numbers Generator Based on Chaotic Iterations. Application to Watermarking
In this paper, a new chaotic pseudo-random number generator (PRNG) is
proposed. It combines the well-known ISAAC and XORshift generators with chaotic
iterations. This PRNG possesses important properties of topological chaos and
can successfully pass NIST and TestU01 batteries of tests. This makes our
generator suitable for information security applications like cryptography. As
an illustrative example, an application in the field of watermarking is
presented.Comment: 11 pages, 7 figures, In WISM 2010, Int. Conf. on Web Information
Systems and Mining, volume 6318 of LNCS, Sanya, China, pages 202--211,
October 201
A novel pseudo-random number generator based on discrete chaotic iterations
Security of information transmitted through the Internet, against passive or
active attacks is an international concern. The use of a chaos-based
pseudo-random bit sequence to make it unrecognizable by an intruder, is a field
of research in full expansion. This mask of useful information by modulation or
encryption is a fundamental part of the TLS Internet exchange protocol. In this
paper, a new method using discrete chaotic iterations to generate pseudo-random
numbers is presented. This pseudo-random number generator has successfully
passed the NIST statistical test suite (NIST SP800-22). Security analysis shows
its good characteristics. The application for secure image transmission through
the Internet is proposed at the end of the paper.Comment: The First International Conference on Evolving Internet:Internet 2009
pp.71--76 http://dx.doi.org/10.1109/INTERNET.2009.1
Randomness Quality of CI Chaotic Generators: Applications to Internet Security
Due to the rapid development of the Internet in recent years, the need to
find new tools to reinforce trust and security through the Internet has became
a major concern. The discovery of new pseudo-random number generators with a
strong level of security is thus becoming a hot topic, because numerous
cryptosystems and data hiding schemes are directly dependent on the quality of
these generators. At the conference Internet`09, we have described a generator
based on chaotic iterations, which behaves chaotically as defined by Devaney.
In this paper, the proposal is to improve the speed and the security of this
generator, to make its use more relevant in the Internet security context. To
do so, a comparative study between various generators is carried out and
statistical results are given. Finally, an application in the information
hiding framework is presented, to give an illustrative example of the use of
such a generator in the Internet security field.Comment: 6 pages,6 figures, In INTERNET'2010. The 2nd Int. Conf. on Evolving
Internet, Valencia, Spain, pages 125-130, September 2010. IEEE Computer
Society Press Note: Best Paper awar
Finding an Effective Metric Used for Bijective S-Box Generation by Genetic Algorithms
In cryptography, S-box is a basic component of symmetric key algorithms which performs nonlinear substitution. S-boxes need to be highly nonlinear, so that the cipher can resist linear cryptanalysis.
The main criteria for cryptographically strong (n Ă— n) S-box are:
• High non linearity;
• High algebraic degree;
• Balanced structure;
• Good auto correlation properties.
Our task was to give some suggestions for finding an effective metric used for generation bijective optimal S-Box. Because of the given problem’s complexity, our group considered different approaches and we gave a few suggestions for problem solving
A New Algorithm for Solving Ring-LPN with a Reducible Polynomial
The LPN (Learning Parity with Noise) problem has recently proved to be of
great importance in cryptology. A special and very useful case is the RING-LPN
problem, which typically provides improved efficiency in the constructed
cryptographic primitive. We present a new algorithm for solving the RING-LPN
problem in the case when the polynomial used is reducible. It greatly
outperforms previous algorithms for solving this problem. Using the algorithm,
we can break the Lapin authentication protocol for the proposed instance using
a reducible polynomial, in about 2^70 bit operations
Boundary information inflow enhances correlation in flocking
The most conspicuous trait of collective animal behaviour is the emergence of
highly ordered structures. Less obvious to the eye, but perhaps more profound a
signature of self-organization, is the presence of long-range spatial
correlations. Experimental data on starling flocks in 3d show that the exponent
ruling the decay of the velocity correlation function, C(r) ~ 1/r^\gamma, is
extremely small, \gamma << 1. This result can neither be explained by
equilibrium field theory, nor by off-equilibrium theories and simulations of
active systems. Here, by means of numerical simulations and theoretical
calculations, we show that a dynamical field applied to the boundary of a set
of Heisemberg spins on a 3d lattice, gives rise to a vanishing exponent \gamma,
as in starling flocks. The effect of the dynamical field is to create an
information inflow from border to bulk that triggers long range spin wave
modes, thus giving rise to an anomalously long-ranged correlation. The
biological origin of this phenomenon can be either exogenous - information
produced by environmental perturbations is transferred from boundary to bulk of
the flock - or endogenous - the flock keeps itself in a constant state of
dynamical excitation that is beneficial to correlation and collective response
Invariants for EA- and CCZ-equivalence of APN and AB functions
An (n,m)-function is a mapping from to . Such functions have numerous applications across mathematics and computer science, and in particular are used as building blocks of block ciphers in symmetric cryptography. The classes of APN and AB functions have been identified as cryptographically optimal with respect to the resistance against two of the most powerful known cryptanalytic attacks, namely differential and linear cryptanalysis. The classes of APN and AB functions are directly related to optimal objects in many other branches of mathematics, and have been a subject of intense study since at least the early 90’s. Finding new constructions of these functions is hard; one of the most significant practical issues is that any tentatively new function must be proven inequivalent to all the known ones. Testing equivalence can be significantly simplified by computing invariants, i.e. properties that are preserved by the respective equivalence relation. In this paper, we survey the known invariants for CCZ- and EA-equivalence, with a particular focus on their utility in distinguishing between inequivalent instances of APN and AB functions. We evaluate each invariant with respect to how easy it is to implement in practice, how efficiently it can be calculated on a computer, and how well it can distinguish between distinct EA- and CCZ-equivalence classes.publishedVersio
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