Served as one of the most widely used wireless airlink interface, CDMA has been identified as a major technique for 3G wireless communications. The current IS-95 CDMA provides a near-satisfactory security solution to voice centric wireless communications, since generally each voice conversation only lasts a very short period of time. However, the security features provided by IS-95 CDMA are far...

In this paper, scan and ring schemes of the pseudo-ring memory self-testing are investigated. Both schemes are based on emulation of the linear or nonlinear feedback shift register by memory itself. Peculiarities of the pseudo-ring schemes implementation for multi-port and embedded memories, and for register file are described. It is shown that only small additional logic is required and allows...

We study the asymptotic behavior of stream cipher security measures associated with classes of sequence generators such as linear feedback shift registers and feedback with carry shift registers. For nonperiodic sequences we consider normalized measures and study the set of accumulation points for a fixed sequence. We see that the the set of accumulation points is always a closed subinterval of...

A d-feedback-with-carry shift register (d-FCSR) is a finite state machine, similar to a linear feedback shift register, in which a small amount of memory and a delay (by d-clock cycles) is used in the feedback algorithm (see [4, 5]). The output sequences of these simple devices may be described using arithmetic in a ramified extension field of the rational numbers. In this paper we show how man...

We present a simple construction of a small probability space on n bits for which any k bits are almost independent. The number of bits used to specify a point in the sample space is O(log log n + k + log ~), where e is the statistical difference between of the distribution induced on any k bit locations and the uniform distribution. This is asymptotically comparable to the construction recentl...

Sum-product message passing (belief propagation) was recently extended to messages/summaries with some nontrivial Markov structure. In this paper, a general update rule for Markov-structured messages is proposed, and further experimental results are presented for the synchronization of noisy linear-feedback shift register (LFSR) sequences.

We determine the imbalances of the keystreams produced by Achterbahn-80 and Achterbahn-128 in two different ways. The number of cyclically inequivalent keystreams produced by the keystream generators of Achterbahn-80 and Achterbahn-128 is determined. An abstract model for the keystream generator of a primitive NLFSR combination generator is used to justify the correlation attack introduced in [...