Date Added: Feb 2012
Cloud computing dynamically provides high quality cloud-based secure services and applications over the internet. The Efficient sharing of Secure Cloud storage services (ESC) scheme which allows the upper-level user to share the secure cloud storage services with multiple lower-level users. In hierarchical identity-based architecture, the sender needs to encrypt a file only once and store only one copy of the corresponding ciphertext in a cloud. The lower-level user needs to decrypt a file which will increase the computational overhead, because the lower-level user does not perform any partial decipherment. In this paper, the authors propose a Trapdoor commitment scheme that enables a lower-level user to send a short trapdoor to the cloud service provider before retrieving files.