Abstract: In Attribute Supported Delegation Model (ABDM) , dclegatee must satisfy both delegation prerequisite condilion (CR) and delegation attribute expression (DAE) when assigned to a delegation role. In AI3DM, revocation focuses on how to revoke those delegated roles or permissions from delegatee. This paper first introduced two new sorts of revocations,which bring about priority between multi step delegation and revocation. hhen analyzed the relation between delegation and revocation and proposed two solutions; "first rectuest first response" and "revocation first then delegalion". We also discussed different situations fitting these two solutions.

Key words: Access control, RBAC, Delegation, Revocation, Attribute