Password Management: Distribution, Review and Revocation

Abstract

We consider the problem of access privilege management in a classical protection environment featuring subjects attempting to access the protected objects. We express an access privilege in terms of an access right and a privilege level. The privilege level and a protection diagram associated with each given object determine whether a nominal access privilege for this object corresponds to an effective, possibly weaker access privilege, or is revoked. We associate a password system with each object; the password system takes the form of a hierarchical bidimensional one-way chain. A subject possesses a nominal access privilege for a given object if it holds a key that matches one of the passwords in the password system of this object; the protection diagram determines the extent of the corresponding effective access privilege. The resulting protection environment has several interesting properties. A key reduction mechanism allows a subject that holds a key for a given object to distribute keys for weaker access rights at lower privilege levels. A subject that owns a given object can review or revoke the passwords for this object by simply modifying the protection diagram. The memory requirements to represent a protection diagram are negligible; as far as password storage is concerned, space-time trade-offs are possible.

Key management in wireless sensor networks

“…In a classical protection system paradigm, a set of active entities, the subjects, generates access attempts to a set of passive entities, the protected objects [10], [11], [12]. When a subject issues an access to a given object, the access terminates successfully only if that subject holds the corresponding access privileges.…”

Access control lists in password capability environments

“…A related problem is that of access right revocation. Several solutions have been proposed to this problem [21]. A propagation graph can be constructed for each capability, which keeps track of all copies of this capability [7].…”

“…In a classic protection system paradigm, a set of active subjects (users, processes) attempts to access a set of passive, typed entities called objects [21], [38]. The type of a given object states the set of the operations that can be executed on this object, and the access rights that are necessary to accomplish each operation successfully.…”

Password systems: Design and implementation

“…the method to restrict the extent of an access privilege by eliminating one or more access rights), and revocation (i.e. the ability to prevent further utilization of a given access privilege) [29]. In the capability list approach, segregation needs to be supported by ad-hoc mechanisms, e.g.…”