Information security aspects of spread spectrum systems

Invited Lecture 3
Part of the Lecture Notes in Computer Science book series (LNCS, volume 917)


Recently spread spectrum systems have been intensively studied and developed for new commercial applications in cellular mobile communication networks and wireless personal communication networks. This is because they have some advantages such as robustness against interference and noise, low probability of intercept, anti-jamming property, high communication capacity per frequency and so on. Some of these features have given spread spectrum systems reputation that they have high information security. A purpose of this paper is to examine this reputation. It is often claimed that in some spread spectrum communication systems, noise and interference have much higher power than the desired signal so that any opponent who does not know the spreading mechanism cannot detect the signal. It is shown, however, that the knowledge of the spreading mechanism gives legitimate users at most about 5 dB advantage of signal to noise ratio over opponents. Therefore, in order to protect privacy, it is recommended to encrypt transmitting data. From the viewpoint of privacy, untraceablity is also important. We propose a registration protocol for cellular systems to keep users unidentified by opponents. From the aspects of information security, the most significant feature peculiar to spread spectrum systems is anti-jamming property. We discuss some designing methodology for spreading mechanisms to strengthen this property.


Spread Spectrum System Information Security CDMA Cellular System Untraceability Jamming 


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  1. 1.
    J.L.Massey, “Information theory aspects of spread-spectrum communications,” Proc. ISSSTA'94, Oulu, Finland, July 1994, pp.16–21.Google Scholar
  2. 2.
    M.K.Simon, J.K.Omura, R.A.Scholtz and B.K.Levitt, Spread Spectrum Communications Handbook (Revised Edition), McGraw-Hill, Inc., New York, 1994.Google Scholar
  3. 3.
    R.C.Dixon, Spread Spectrum Systems with Commercial Applications (Third Edition), John-Wiley & Sons, Inc., New York, 1994.Google Scholar
  4. 4.
    H.Imai and R.Kohno, Advanced Spread Spectrum Communication Techniques and Applications, Elsevier, Amsterdam, to be published.Google Scholar
  5. 5.
    K. S. Gilhousen, I. M. Jacobs, R. Padovani, A. J. Viterbi, L. A. Weaver, and C. E. Wheatley, “On the capacity of cellular CDMA system,” IEEE Trans. Vehicular Technology, vol. 40, no.2, May 1991, pp. 303–312.Google Scholar
  6. 6.
    A.J.Viterbi, “The orthogonal-random waveform dichotomy for digital mobile personal communication,” IEEE Personal Communications, First Quarter 1994, pp.18–24.Google Scholar
  7. 7.
    R.Padovani, “Reverse link performance of IS-95 based cellular systems,” IEEE Personal Communications, Third Quarter 1994, pp.28–34.Google Scholar
  8. 8.
    Y.C.Lee, “Overview of cellular CDMA,” IEEE Trans. Vehicular Technology, vol. 40, no.2, May 1991, pp. 291–302.Google Scholar
  9. 9.
    N.Suehiro, “Secret sequence assignment for approximately synchronized CDMA system without co-channel interference,” Technical Report of IEICE, IT93-104, Jan. 1994, pp. 55–60.Google Scholar
  10. 10.
    K.Imamura and S.Uehara, “Relation between periodic sequences of the maximum linear complexity and m-sequences,” Proc. SITA'93, Kanazawa, Japan, Oct. 1993, pp.255–257.Google Scholar
  11. 11.
    H.Imai, R.Kohno and T.Matsumoto, “Information security of spread spectrum systems,” IEICE Trans., vol. E74, no.3, March 1991, pp. 488–505.Google Scholar
  12. 12.
    C.E.Shannon, “A mathematical theory of communication,” Bell System Technical Journal, vol. 27, July and Oct. 1948, pp. 379–423 (Part I) and 623–656 (Part II).Google Scholar
  13. 13.
    A.J.Viterbi, “Phase-coherent communication over the continuous Gaussian channel,” S.W.Golomb ed., Digital Communication with Space Applications, Prentice-Hall, 1964, pp.106–134.Google Scholar
  14. 14.
    R.G.Gallager, Information Theory and Reliable Communication, John Wiley & Sons, Inc., New York, 1986.Google Scholar
  15. 15.
    A.Polydoros and S.Glisic, “Code synchronization: A review of principle and techniques,” Proc. IEEE ISSSTA'94, Oulu, Finland, July 1994, pp.115–137.Google Scholar
  16. 16.
    R.Kohno, H.Imai and M.Hatori, “Cancellation technique of co-channel interference in asynchronous spread spectrum multiple access systems,” IECE Trans., vol. J65-A, no.5, May 1983, pp. 416–423.Google Scholar
  17. 17.
    S.Verdu, “Optimum multiuser asymptotic efficiency,” IEEE Trans. Communications, vol. COM-34, no.9, Sept. 1986, pp. 85–96.Google Scholar
  18. 18.
    P.D.Alexander, A.J.Grant and M.J.Miller, “Multiuser mobile communications,” presented at ISITA'94, Sydney, Australia, Nov. 1994.Google Scholar
  19. 19.
    Y.C.Yoon, R.Kohno, and H. Imai, “A spread-spectrum multiaccess system with cochannel interference cancellation for mulitipath fading channels,” IEEE J. Select. Areas Communications, vol. 11, no.7, Sept. 1993, pp. 1067–1075.Google Scholar
  20. 20.
    R.Bird, I.Gopal, A.Herzberg, P.Janson, S.Kutten, R.Molve, and M.Yung, “Systematic design of two-party authentication protocols,” Advances in Cryptology—CRYPTO'91, Springer-Verlag, 1991, pp.44–61.Google Scholar
  21. 21.
    W.Diffie, P.C.van Oorschot and M.J.Wiener, “Authentication and authenticated key exchanges,” Design, Codes and Cryptography, Kluwer Academic Publishers, vol.2, 1992, pp.107–125.Google Scholar
  22. 22.
    A.Aziz and W.Diffie, “Privacy and authentication for wireless local area networks,” IEEE Personal Communications, First Quarter 1994, pp.25–31.Google Scholar
  23. 23.
    T.Matsumoto and H.Imai, “On the key predistribution system: A practical solution to the key distribution problem,” Advances in Cryptology — CRYPTO'87, Springer-Verlag, 1987, pp.185–193.Google Scholar
  24. 24.
    T.Matsumoto, Y.Takashima, H.Imai, M.Sasaki, H.Yoshikawa, and S.Watanabe, “A prototype KPS and its application: IC card based key sharing and cryptographic communication,” IEICE Trans., vol. E73, no.7, July 1990, pp. 1092–1099.Google Scholar
  25. 25.
    Z.Tang and S.Cheng, “Pre-decorrelating single user detection for CDMA system,” Proc. IEEE VTC'94, Stockholm, Sweden, June 1994, vol. 2, pp. 767–769.Google Scholar
  26. 26.
    M.Isaka and H.Imai, “A scheme of code orthogonalization in the down link of cellular CDMA (in Japanese),” Proc. SITA '94, Hiroshima, Japan, Dec. 1994, pp.277–280.Google Scholar
  27. 27.
    M.B.Pursley, “Reed-Solomon codes in frequency-hop communications,” S.B.Wicker and V.K.Bhargava eds., Reed-Solomon Codes and Their Applications, Chap. 8, IEEE Press, NJ, 1994, pp. 150–174.Google Scholar
  28. 28.
    D.Sarwate, “Reed-Solomon codes and the design of sequences for spread-spectrum multiple-access communications,” S.B.Wicker and V.K.Bhargava eds., Reed-Solomon Codes and Their Applications, Chap. 9, IEEE Press, NJ, 1994, pp. 175–204.Google Scholar
  29. 29.
    J.Iwatani and H.Imai, “Coding for multiple access OR channel (in Japanese),” Proc. SITA '94, Hiroshima, Japan, Dec. 1994, pp.389–392.Google Scholar
  30. 30.
    E.Okamoto, W.Aitken, G.R.Blakley, and I.Borosh, “Properties of permutation polynomials,” Proc. SITA'94, Hiroshima, Japan, Dec. 1994, pp.381–384.Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  1. 1.Institute of Industrial ScienceThe University of TokyoTokyoJapan

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