Trust-management subjects face the problem of discovering credential chain. In this paper, the distributed credential chain discovery algorithms in trust-management with parameterized roles are proposed. The algorithms extend the RT
’s and are goal-oriented also. Based on the concept of parameterized roles in RT
, they search the credential graph via the constant matching and variable solving mechanisms. The algorithms can perform chain discovery in most trust-management systems and can support the protection of access control policies during automated trust negotiation. Soundness and completeness of the algorithms are given.