1. Trust relationships in secure systems—a distributed authentication perspective;Yahalom,1993
2. Valuation of trust in open networks;Beth,1994
3. A global authentication service without global trust;Birrell,1986
4. X.509, The Directory-Authentication Framework;International Telegraph and Telephone Consultative Commitee (CCITT),1988
5. Authentication in distributed systems: theory and practice;Lampson,1991