Multi-authority proxy re-encryption based on CPABE for cloud storage systems

The dissociation between data management and data ownership makes it difficult to protect data security and privacy in cloud storage systems.Traditional encryption technologies are not suitable for data protection in cloud storage systems.A novel multi-authority proxy re-encryption mechanism based on ciphertext-policy attribute-based encryption（MPRE-CPABE） is proposed for cloud storage systems.MPRE-CPABE requires data owner to split each file into two blocks,one big block and one small block.The small block is used to encrypt the big one as the private key,and then the encrypted big block will be uploaded to the cloud storage system.Even if the uploaded big block of file is stolen,illegal users cannot get the complete information of the file easily.Ciphertext-policy attribute-based encryption（CPABE）is always criticized for its heavy overload and insecure issues when distributing keys or revoking user＇s access right.MPRE-CPABE applies CPABE to the multi-authority cloud storage system,and solves the above issues.The weighted access structure（WAS） is proposed to support a variety of fine-grained threshold access control policy in multi-authority environments,and reduce the computational cost of key distribution.Meanwhile,MPRE-CPABE uses proxy re-encryption to reduce the computational cost of access revocation.Experiments are implemented on platforms of Ubuntu and CloudSim.Experimental results show that MPRE-CPABE can greatly reduce the computational cost of the generation of key components and the revocation of user＇s access right.MPRE-CPABE is also proved secure under the security model of decisional bilinear Diffie-Hellman（DBDH）.

A Novel Provable Data Possession Scheme Based on Geographic Location Attribute

Increment of mobile cloud video motivates mobile users to utilize cloud storage service to address their demands, cloud storage provider always furnish a location-independent platform for managing user＇s data. However, mobile users wonder if their cloud video data leakage or dynamic migration to illegal service providers. In this paper, we design a novel provable data possession protocol based on data geographic location attribute, which allows data owner to auditing the integrity of their video data, which put forward an ideal choice for remote data possession checking in the mobile cloud storage. In our proposed scheme, we check out whether the video data dynamic migrate to an unspecified location （such as： overseas） by adding data geographic location attribute tag into provable data possession protocol. Moreover, we make sure the security of our proposed scheme under the Computational Diffic-Hellman assumption. The analysis and experiment results demonstrate that our proposed scheme is provably secure and efficient.

A novel DNA-inspired encryption strategy for concealing cloud storage

Over the last few years,the need of a cloud environment with the ability to detect illegal behaviours along with a secured data storage capability has increased largely.This study presents such a secured cloud storage framework comprising of a deoxyribonucleic acid(DNA)based encryption key which has been generated to make the framework unbreakable,thus ensuring a better and secured distributed cloud storage environment.Furthermore,this work proposes a novel DNA-based encryption technique inspired by the biological characteristics of DNA and the protein synthesis mechanism.The introduced DNA based model also has an additional advantage of being able to decide on selecting suitable storage servers from an existing pool of storage servers on which the data must be stored.A fuzzy-based technique for order of preference by similarity to ideal solution(TOFSIS)multi-criteria decisionmaking(MCDM)model has been employed to achieve the above-mentioned goal.This can decide the set of suitable storage servers and also results in a reduction in execution time by keeping up the level of security to an improved grade.This study also investigates and analyzes the strength of the proposed S-Box and encryption technique against some standard criteria and benchmarks,such as avalanche effect,correlation coefficient,information entropy,linear probability,and differential probability etc.After the avalanche effect analysis,the average change in cipher-text has been found to be 51.85%.Moreover,thorough security,sensitivity and functionality analysis show that the proposed scheme guarantees high security with robustness.