Re: A variant of the shrinking generator

From: AE (hidden_at_nospam.com)
Date: 07/15/04 

Date: Thu, 15 Jul 2004 20:59:16 +0200

What you are describing is a Geffe generator. It's weak:

E.L.Key "An Analysis of the Structure and Complexity of Nonlinear
Binary Sequence Generators," IEEE Transactions on Information Theory,
v.IT-22, n. 6, Nov. 1976, pp. 732-736

K.C.Zeng, C.-H. Yang and T.R.N. Rao, "On the Linear Consistency Test
(LCT) in Cryptanalysis with Applications," Advances in Cryptology -
CRYPTO '89 Proceedings, Springer-Verlag, 1990, pp. 164-174

Better is the alternating stop-and-go-generator:

C.G.Günther, "Alternating Step Generators Controlled by de Brujin
Sequences," Advances in Cryptology -- EUROCRYPT '87 Proceedings,
Springer-VErlag, 1988, pp 5-14

Regards,
Andreas