Despite that existing data sharing systems in online social networks(OSNs)propose to encrypt data before sharing,the multiparty access control of encrypted data has become a challenging issue.In this paper,we propose ...Despite that existing data sharing systems in online social networks(OSNs)propose to encrypt data before sharing,the multiparty access control of encrypted data has become a challenging issue.In this paper,we propose a secure data sharing scheme in 0SNs based on ciphertext-policy attribute-based proxy re-encryption and secret sharing.In order to protect users'sensitive data,our scheme allows users to customize access policies of their data and then outsource encrypted data to the OSNs service provider.Our scheme presents a multiparty access control model,which enables the disseminator to update the access policy of ciphertext if their attributes satisfy the existing access policy.Further,we present a partial decryption construction in which the computation overhead of user is largely reduced by delegating most of the decryption operations to the OSNs service provider.We also provide checkability on the results returned from the OSNs service provider to guarantee the correctness of partial decrypted ciphertext.Moreover,our scheme presents an efficient attribute revocation method that achieves both forward and backward secrecy.The security and performance analysis results indicate that the proposed scheme is secure and efficient in OSNs.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
The online social networks（OSNs） offer attractive means for social interactions and data sharing, as well as raise a number of security and privacy issues. Although current solutions propose to encrypt data before s...The online social networks（OSNs） offer attractive means for social interactions and data sharing, as well as raise a number of security and privacy issues. Although current solutions propose to encrypt data before sharing, the access control of encrypted data has become a challenging task. Moreover, multiple owners may enforce different access policy to the same data because of their different privacy concerns. A digital rights management（DRM） scheme is proposed for encrypted data in OSNs. In order to protect users＇ sensitive data, the scheme allows users outsource encrypted data to the OSNs service provider for sharing and customize the access policy of their data based on ciphertext-policy attribute-based encryption. Furthermore, the scheme presents a multiparty access control model based on identity-based broadcast encryption and ciphertext-policy attribute-based proxy re-encryption, which enables multiple owners, such as tagged users who appear in a single data, customize the access policy collaboratively, and also allows the disseminators update the access policy if their attributes satisfy the existing access policy. Security analysis and comparison indicate that the proposed scheme is secure and efficient.展开更多
属性加密方案是一种对身份加密方案进行扩展,能够实现细粒度数据访问控制的密码学方案,特别是密文策略属性加密方案(Ciphertext Policy Attribute Based Encryption,CP-ABE)能够实现用户自定义访问控制策略,因此,在云存储环境下得到了...属性加密方案是一种对身份加密方案进行扩展,能够实现细粒度数据访问控制的密码学方案,特别是密文策略属性加密方案(Ciphertext Policy Attribute Based Encryption,CP-ABE)能够实现用户自定义访问控制策略,因此,在云存储环境下得到了越来越广泛的应用。在CP-ABE方案中,密文与某个访问控制策略相关,其加密计算量随着访问控制策略规模的增大而增加,造成了严重的计算负载。为了提高CP-ABE方案的加密性能,提出了一种新的CP-ABE加密技术,对加密算法进行了改进,分为离线和在线两个加密过程。其中,离线加密可以在准备阶段完成加密预处理,在线加密则可以基于预处理结果快速高效地完成最终加密。展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61272519the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20120005110017the National Key Technology R&D Program under Grant No.2012BAH06B02
文摘Despite that existing data sharing systems in online social networks(OSNs)propose to encrypt data before sharing,the multiparty access control of encrypted data has become a challenging issue.In this paper,we propose a secure data sharing scheme in 0SNs based on ciphertext-policy attribute-based proxy re-encryption and secret sharing.In order to protect users'sensitive data,our scheme allows users to customize access policies of their data and then outsource encrypted data to the OSNs service provider.Our scheme presents a multiparty access control model,which enables the disseminator to update the access policy of ciphertext if their attributes satisfy the existing access policy.Further,we present a partial decryption construction in which the computation overhead of user is largely reduced by delegating most of the decryption operations to the OSNs service provider.We also provide checkability on the results returned from the OSNs service provider to guarantee the correctness of partial decrypted ciphertext.Moreover,our scheme presents an efficient attribute revocation method that achieves both forward and backward secrecy.The security and performance analysis results indicate that the proposed scheme is secure and efficient in OSNs.
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.
基金supported by the National Natural Science Foundation of China(60803157,90812001,61272519)
文摘The online social networks（OSNs） offer attractive means for social interactions and data sharing, as well as raise a number of security and privacy issues. Although current solutions propose to encrypt data before sharing, the access control of encrypted data has become a challenging task. Moreover, multiple owners may enforce different access policy to the same data because of their different privacy concerns. A digital rights management（DRM） scheme is proposed for encrypted data in OSNs. In order to protect users＇ sensitive data, the scheme allows users outsource encrypted data to the OSNs service provider for sharing and customize the access policy of their data based on ciphertext-policy attribute-based encryption. Furthermore, the scheme presents a multiparty access control model based on identity-based broadcast encryption and ciphertext-policy attribute-based proxy re-encryption, which enables multiple owners, such as tagged users who appear in a single data, customize the access policy collaboratively, and also allows the disseminators update the access policy if their attributes satisfy the existing access policy. Security analysis and comparison indicate that the proposed scheme is secure and efficient.
文摘属性加密方案是一种对身份加密方案进行扩展,能够实现细粒度数据访问控制的密码学方案,特别是密文策略属性加密方案(Ciphertext Policy Attribute Based Encryption,CP-ABE)能够实现用户自定义访问控制策略,因此,在云存储环境下得到了越来越广泛的应用。在CP-ABE方案中,密文与某个访问控制策略相关,其加密计算量随着访问控制策略规模的增大而增加,造成了严重的计算负载。为了提高CP-ABE方案的加密性能,提出了一种新的CP-ABE加密技术,对加密算法进行了改进,分为离线和在线两个加密过程。其中,离线加密可以在准备阶段完成加密预处理,在线加密则可以基于预处理结果快速高效地完成最终加密。
