De Bruijn sequences as secure spreading codes for wireless communications

Abstract

In wireless communication systems, physical layer elements are open to possible attacks by eavesdroppers and undesired entities. The basic premise of spread spectrum techniques is to mask user information by spreading the original message over the whole bandwidth. To this aim, pseudorandom codes may be used. However, traditional families of codes are publicly known and no longer trustworthy to provide protection against malicious users. The paper proposes the use of De Bruijn sequences as the next generation set of spreading codes, for their cardinality and correlation properties. Here, different spans of De Bruijn codes are analyzed to examine their performance over spread spectrum channels. It is shown that the codes provide acceptable results with respect to various security tests, like the Golomb's postulates, Berlekamp's linear complexity, and five basic tests on randomness, recommended by the National Institute of Standards and Technology (NIST).