Trust management in privacy — Preserving information system

In many information management applications, sensitive information must be stored as a record and be retrieved when necessary. When the recored is stored in a distributed way in multiple databases and shared by multiple users with different trust levels and accessing privileges, the trust management model is called M-to-M model. In this model, on one hand the record is stored in a distributed way; one the other hand every user obtains a different version of the record in their retrieving operations according to their different trust levels and access privileges. A scheme is proposed in this paper to specify M-to-M trust management. The new scheme not only realizes privacy-preserving information storage and sharing in a multi-level-trust environment, but also achieves robustness through information redundancy. The new technique is quite simple and does not need any cryptographic operation like encryption, digital signature or hash function, so its security is unconditional and does not depend on any computational assumption.