ABSTRACT
The theory of stream ciphers was stated by Rueppel [12) and later connected to continued fractions by Niederreiter [4], [6], [7], and Vielhaber (13] as well as in joint papers [8], [9], (10].
It is desirable that the so-called linear complexity profile of a given pseudorandom sequence!! E F~ does not have large jumps, or stated equivalently that the continued fraction expansion (c.f.e)
G( ) "" -• 1 I 1 I 1 I ,q,x = ~otx = IPt(x) + !P2(x) + IPa(x) + ···' consists only of polynomials Pi of bounded degree deg(pi) ~ d for a certain fixed number dEN.
