Secure and efficient access to outsourced data

Abstract

Providing secure and efficient access to large scale outsourced data is an important component of cloud computing. In this paper, we propose a mechanism to solve this problem in owner-write-users-read applications. We propose to encrypt every data block with a different key so that flexible cryptography-based access control can be achieved. Through the adoption of key derivation methods, the owner needs to maintain only a few secrets. Analysis shows that the key derivation procedure using hash functions will introduce very limited computation overhead. We propose to use over-encryption and/or lazy revocation to prevent revoked users from getting access to updated data blocks. We design mechanisms to handle both updates to outsourced data and changes in user access rights. We investigate the overhead and safety of the proposed approach, and study mechanisms to improve data access efficiency.

ABE Based Online Personal Health Record System Using Cloud Computing

“…However, user revocation is not supported. In [9], an owner's data is encrypted block-by-block, and a binary key tree is constructed over the block keys to reduce the number of keys given to each user. The SKC-based solutions have several key limitations.…”

On the Insecurity of a Method for Providing Secure and Private Fine-Grained Access to Outsourced Data

“…Different techniques have been proposed to protect data outsourced to the cloud [3], [4], [5]. Among them, attribute-based access control has been given a lot of attention in recent years [6], [7], [8], [9].…”

Privacy enhanced data outsourcing in the cloud

“…With the tree-based ideas, some key management methods of access hierarchies for data outsourcing have been proposed [4,5,6,7,8]. These methods provide some useful solutions to minimize the number of cryptographic keys, which have to be managed and stored.…”

“…These methods provide some useful solutions to minimize the number of cryptographic keys, which have to be managed and stored. Aiming to provide secure and efficient access to outsourced data, Wang, Li et al [4] proposed a tree-based cryptographic key management scheme for data storages in the cloud. They referred the scenario to as "owner-write-users-read".…”

“…This is a common problem which exists in many tree-based key management schemes. The existing ones such as [4,9,7,10,11,12,13,14,15,16,17,18,19] could work perfectly, only when all legitimate node users are authorized to access all the child nodes under the specific one.…”