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 ...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）.展开更多
云辅助医疗物联网系统是智慧医疗领域发展的新趋势,患者隐私数据通常以密态的形式外包存储于云端,这将导致数据拥有者失去对自身数据的控制权限,并带来数据检索不便.针对上述问题,本文提出了一种支持策略隐藏的可搜索属性加密方案,结合...云辅助医疗物联网系统是智慧医疗领域发展的新趋势,患者隐私数据通常以密态的形式外包存储于云端,这将导致数据拥有者失去对自身数据的控制权限,并带来数据检索不便.针对上述问题,本文提出了一种支持策略隐藏的可搜索属性加密方案,结合密文策略属性加密与公钥可搜索加密的优势,确保云辅助(cloud-assisted Internet of Medical Things,IoMT)系统中共享数据的机密性,实现了敏感数据的细粒度访问控制并支持关键字搜索.并且,利用在线/离线加密和外包解密等方法降低了资源受限设备的计算开销,使得密文策略的属性加密方案可以在云辅助IoMT系统中实施.同时,引入策略隐藏技术,将属性加密访问策略中的属性值隐藏于密文中,防止数据拥有者的隐私泄露.在安全性方面,证明本方案的密文信息在选定访问结构和选择明文攻击下具有不可区分性,以及陷门信息在选择关键字攻击下具有不可区分性.最后,利用JPBC(Javapairing-based cryptography)密码库对本方案与其他相关方案在功能特性、通信开销和计算开销等方面进行对比,结果表明本方案在密钥生成和加密阶段计算效率更高且存储开销更低.展开更多
基金supported by the National Natural Science Foundation of China(6120200461472192)+1 种基金the Special Fund for Fast Sharing of Science Paper in Net Era by CSTD(2013116)the Natural Science Fund of Higher Education of Jiangsu Province(14KJB520014)
文摘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）.
文摘云辅助医疗物联网系统是智慧医疗领域发展的新趋势,患者隐私数据通常以密态的形式外包存储于云端,这将导致数据拥有者失去对自身数据的控制权限,并带来数据检索不便.针对上述问题,本文提出了一种支持策略隐藏的可搜索属性加密方案,结合密文策略属性加密与公钥可搜索加密的优势,确保云辅助(cloud-assisted Internet of Medical Things,IoMT)系统中共享数据的机密性,实现了敏感数据的细粒度访问控制并支持关键字搜索.并且,利用在线/离线加密和外包解密等方法降低了资源受限设备的计算开销,使得密文策略的属性加密方案可以在云辅助IoMT系统中实施.同时,引入策略隐藏技术,将属性加密访问策略中的属性值隐藏于密文中,防止数据拥有者的隐私泄露.在安全性方面,证明本方案的密文信息在选定访问结构和选择明文攻击下具有不可区分性,以及陷门信息在选择关键字攻击下具有不可区分性.最后,利用JPBC(Javapairing-based cryptography)密码库对本方案与其他相关方案在功能特性、通信开销和计算开销等方面进行对比,结果表明本方案在密钥生成和加密阶段计算效率更高且存储开销更低.
