1. F. Stajano, “Security for Ubiquitous Computing,” John Wiley & Sons, 2002.
2. R. E. Smith, “Authentication: from passwords to public keys,” Addison Wesley, 2001.
3. L. Kagal, J. L. Undercoffer, F. Perich, A. Joshi, T. Finin, and Y. Yesha, “Vigil: Providing Trust for Enhanced Security in Pervasive Systems,” University of Maryland Techical Report, 2002.
4. A. Birrell, B. Lampson, R. M. Needham, and M. D. Schroeder, “A Global Authentication Service without Global Trust,” Symposium on Security and Privacy: IEEE, pp. 223–230, 1986.
5. M. Weiser, “The Computer for the 21st Century,” Scientific American, 1991.