A Dispersed Multi-Value Attribute-Based Encryption With Mediated Obfuscation

Abstract

The Multi-authority attribute-based encryption (MA-ABE) scheme can provide fine-grained data access control in many management domains monitored by different authorities for the cloud storage system. However, existed schemes do not support the flexible management of authorities. So, we present a new dispersed multi-value MA-ABE scheme with mediated obfuscation (DMV-ABE-WMO). In this scheme, each of attribute authorities ( $AAs$ ) works independently without any collaboration with other $AAs$ . For a data user (DU), data owner (DO) individually creates ciphertext in each management domain and each attribute authority ( $AA$ ) also individually generates a private key in each management domain, respectively. We use the mediated obfuscation (MO) model to embed a secret related to DU into all target components which are used to encrypt the plaintext. In MO model, an especial function program is coded into the form of a group element, which is obfuscated to make other participants know nothing about the inner program but can evaluate the value of the function program. Our scheme is based on multi-value access structure and is proved secure against chosen plaintext attack. Compared with the related schemes, our scheme is more suited for realizing the dynamic management in many domains.