Anzeige
Erschienen in:
2009 | OriginalPaper | Buchkapitel
Attacking Power Generators Using Unravelled Linearization: When Do We Output Too Much?
verfasst von : Mathias Herrmann, Alexander May
Erschienen in: Advances in Cryptology – ASIACRYPT 2009
Verlag: Springer Berlin Heidelberg
Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.
Wählen Sie Textabschnitte aus um mit Künstlicher Intelligenz passenden Patente zu finden. powered by
Markieren Sie Textabschnitte, um KI-gestützt weitere passende Inhalte zu finden. powered by
We look at iterated power generators
$s_i = s_{i-1}^e {\rm mod} N$
for a random seed
s
0
∈ ℤ
N
that in each iteration output a certain amount of bits. We show that heuristically an output of
$(1-\frac 1 e)\log N$
most significant bits per iteration allows for efficient recovery of the whole sequence. This means in particular that the Blum-Blum-Shub generator should be used with an output of less than half of the bits per iteration and the RSA generator with
e
= 3 with less than a
$\frac 1 3$
-fraction of the bits.
Our method is lattice-based and introduces a new technique, which combines the benefits of two techniques, namely the method of linearization and the method of Coppersmith for finding small roots of polynomial equations. We call this new technique
unravelled linearization
.