On the joint 2-adic complexity of binary multisequences∗
State Key Laboratory of Networking and Switching Technology, P.O.
Box 305, Beijing University of Posts and Telecommunications,
2 State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, Beijing 100876, P.R. China
Accepted: 16 February 2012
Joint 2-adic complexity is a new important index of the cryptographic security for multisequences. In this paper, we extend the usual Fourier transform to the case of multisequences and derive an upper bound for the joint 2-adic complexity. Furthermore, for the multisequences with pn-period, we discuss the relation between sequences and their Fourier coefficients. Based on the relation, we determine a lower bound for the number of multisequences with given joint 2-adic complexity.
Mathematics Subject Classification: 11T71 / 14G50 / 94A60
Key words: Cryptography / stream cipher / FCSR / joint 2-adic complexity / usual Fourier transform
© EDP Sciences 2012