Abstract

Today electronic messaging services are indispensableto individuals and organizations. If a messagecontains sensitive information, the integrity and confidentialityof the contents created by individual users should bemaintained in an effective manner. Therefore, there is anurgent need for new mechanisms to support the requirement.In this paper we focus on the message protection inthe organization-to-organization service, while many otherresearchers have worked on the person-to-person service.Our approaches can provide effective integrity verification,tracking mechanisms, and confidentiality at the user-level ina scalable manner with fine granularity. Furthermore, weuse a set of session keys for each message to provide more securecommunications, maintaining scalable key managementby employing a key hierarchy. We describe the mechanismsof our approaches and show their feasibility by describinga prototype system that we developed.