Research On Security Audit Technology Of Cloud Storage Medical Big Data Based On Wireless Body Area Networ

Medical cloud storage service is an important application of cloud computing.It provides users with a convenient,flexible and efficient way of data management,under the era of health and medical data explosion.Due to the sensitivity of medical data,the openness of data transmission and storage,the complexity of the system and the high-frequency of attacks in the public network environment,the medical data and the identity privacy of users are faced with severe security threats.Especially,once the vital physiological characteristic parameter of users is collected through wireless medical sensor devices and then uploaded to the medical cloud server in real time via wireless body area networks,users will completely lose their physical control over these data,which may cause the data more vulnerable to online eavesdropping,malicious deletion or tampering from external adversaries.Thus,how to employ cryptographic security techniques to ensure the integrity and confidentiality of medical cloud storage data,as well as the anonymity of users has become an important and hot research topic.This dissertation investigated privacy-preserving auditing schemes for medical data in cloud storage associated with wireless body area networks(WBANs).The main contents of the dissertation are as follows:(1)Initially,an identity-based proxy-oriented outsourcing with public auditing in cloud-based medical data scheme,dubbed IBPOPA,has been proposed,which can achieve the functionality of batch auditing and authorized proxy uploading.Besides,the system model and security model of this scheme were formally presented.We employed the stream cipher algorithm to ensure the confidentiality of medical data.Simultaneously,we designed a homomorphic linear signature algorithm based on elliptic curve cryptography to ensure the integrity of medical data.Specifically,an authorization warrant for the original user was created,and the original data owner can take advantage of the private key to generate a digital signature for the warrant,thereby achieving a reliable proxy process between the original user and proxy.Finally,the security of this scheme was strictly proved and its performance was compared with existing schemes.The result shows that our scheme has higher advantages in the application environment of cloud-assisted wireless area body networks(2)Secondly,a public auditing scheme for big data in medical cloud storage with conditional identity privacy,dubbed CIDPA,has been put forward,and its system model and security model have been also presented.The proposed scheme achieves conditional anonymity so that even if the sensitive medical data are exposed,an outside adversary would not know about the real identity of the corresponding patient.Meanwhile,combining traceability mechanism,a malicious user in the medical information system is more likely to be tracked and revealed in the scheme.In addition,an effective random masking code technique has been designed to resist a curious third-party auditor.We have provided the security proofs,and the hardness could be reduced to the Discrete Logarithm problem and the computational Diffie-Hellman problem.(3)Thirdly,we presented a blockchain-assisted secure cloud storage public-auditing scheme for medical data in WBANs,dubbed EBDSA.Based on the proposed CIDPA scheme,EBDSA further expands the security functionality of data auditing.In particular,we consider a more aggressive security model,which assumes that a third-party auditor is a semi-trusted entity.The auditor would collude with internal and external adversaries to modify the audit results for the purpose of saving the auditing cost or for the sake of business interests.Therefore,the ethereum blockchain technology was embedded into the data auditing scheme to resist such malicious behaviors.Finally,through the comprehensive performance comparison,we conclude that EBDSA is more suitable to be deployed in cloud-assisted wireless area body networks.