25 research outputs found
Elliptic periods for finite fields
We construct two new families of basis for finite field extensions. Basis in
the first family, the so-called elliptic basis, are not quite normal basis, but
they allow very fast Frobenius exponentiation while preserving sparse
multiplication formulas. Basis in the second family, the so-called normal
elliptic basis are normal basis and allow fast (quasi linear) arithmetic. We
prove that all extensions admit models of this kind
Normal Elliptic Bases and Torus-Based Cryptography
We consider representations of algebraic tori over finite fields.
We make use of normal elliptic bases to show that, for infinitely many
squarefree integers and infinitely many values of , we can encode
torus elements, to a small fixed overhead and to -tuples of
elements, in quasi-linear time in .
This improves upon previously known algorithms, which all have a
quasi-quadratic complexity. As a result, the cost of the encoding phase is now
negligible in Diffie-Hellman cryptographic schemes
On Modular Inverses of Cyclotomic Polynomials and the Magnitude of their Coefficients
Let p and r be two primes and n, m be two distinct divisors of pr. Consider
the n-th and m-th cyclotomic polynomials. In this paper, we present lower and
upper bounds for the coefficients of the inverse of one of them modulo the
other one. We mention an application to torus-based cryptography.Comment: 21 page
Construction of self-dual normal bases and their complexity
Recent work of Pickett has given a construction of self-dual normal bases for
extensions of finite fields, whenever they exist. In this article we present
these results in an explicit and constructive manner and apply them, through
computer search, to identify the lowest complexity of self-dual normal bases
for extensions of low degree. Comparisons to similar searches amongst normal
bases show that the lowest complexity is often achieved from a self-dual normal
basis
On the construction of elliptic Chudnovsky-type algorithms for multiplication in large extensions of finite fields
International audienceWe indicate a strategy in order to construct bilinear multiplication algorithms of type Chudnovsky in large extensions of any finite field. In particular, using the symmetric version of the generalization of Randriambololona specialized on the elliptic curves, we show that it is possible to construct such algorithms with low bilinear complexity. More precisely, if we only consider the Chudnovsky-type algorithms of type symmetric elliptic, we show that the symmetric bilinear complexity of these algorithms is in O(n(2q)^log * q (n)) where n corresponds to the extension degree, and log * q (n) is the iterated logarithm. Moreover, we show that the construction of such algorithms can be done in time polynomial in n. Finally, applying this method we present the effective construction, step by step, of such an algorithm of multiplication in the finite field F 3^57. Index Terms Multiplication algorithm, bilinear complexity, elliptic function field, interpolation on algebraic curve, finite field