Cryptographic CDMA code hopping (CH-CDMA) for signal security and anti-jamming
Frank Hermanns · elib (German Aerospace Center) · 2004
Today, military and commercial Spread Spectrum and CDMA transmission systems argue with security on the physical layer based on the secrecy of the seed values of static secure (and insecure) pseudorandom noise generators (PRNG). This should prevent eavesdropping and jamming [1, 2]. Confidentiality, data integrity and authenticity are usually realized in higher protocol layers [3]. Nevertheless, physical layer security is a valuable component of a high-end system security. Relying on one security layer alone is dangerous, because vulnerabilities are constantly discovered, compromising the overall system security (GSM, WLAN ...) [4]. With additional physical layer security measures, attacks on the upper security layers will be much more difficult. Furthermore, some security elements can only be realized on the physical layer (anti-jamming and low-detectability). Especially CDMA systems have a great potential to evolve their security strength with modifications proposed in this paper.