The cloud allows clients to store and share data.Depending on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved users.The user loses control of t...The cloud allows clients to store and share data.Depending on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved users.The user loses control of their data when the data is outsourced to the cloud.Therefore,access control mechanisms will become a significant challenging problem.The Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is an essential solution in which the user can control data access.CP-ABE encrypts the data under a limited access policy after the user sets some access policies.The user can decrypt the data if they satisfy the limited access policy.Although CP-ABE is an effective access control program,the privacy of the policy might be compromised by the attackers.Namely,the attackers can gather important information from plain text policy.To address this issue,the SHA-512 algorithm is presented to create a hash code for the user’s attributes in this paper.Depending on the created hash codes,an access policy will be formed.It leads to protecting the access policy against attacks.The effectiveness of the proposed scheme is assessed based on decryption time,private key generation time,ciphertext generation time,and data verification time.展开更多
In this paper, we present the first ciphertext-policy attribute-based encryption （CP-ABE） scheme for polynomial-size general circuits based on bilinear maps which is more suitable for practical use and more efficien...In this paper, we present the first ciphertext-policy attribute-based encryption （CP-ABE） scheme for polynomial-size general circuits based on bilinear maps which is more suitable for practical use and more efficient than multilinear maps. Our scheme uses a top-down secret sharing and FANOUT gate to resist the ＂backtracking attack＂ which is the main barrier expending access tree to general circuit. In the standard model, selective security of our scheme is proved. Comparing with current scheme for general circuits from bilinear maps, our work is more efficient.展开更多
For leakage-resilient ciphertext-policy attribute-based encryption （CP-ABE） at present, the size of the ciphertexts in most of them relies on the number of attributes. How to overcome this shortcoming is a challenge...For leakage-resilient ciphertext-policy attribute-based encryption （CP-ABE） at present, the size of the ciphertexts in most of them relies on the number of attributes. How to overcome this shortcoming is a challenge problem. Based on the Goldreich-Levin theorem and dual system encryption, an efficient CP-ABE scheme with constant size ciphertexts is proposed in this paper. It can tolerate leakage on master secret key and attribute-based secret keys with auxiliary inputs. Furthermore, the proposed scheme can be realized as resilience against continual leakage if keys are periodically updated. Under some static assumptions instead of other strong assumptions, the introduced scheme achieves adaptively security in the standard model.展开更多
针对现有防篡改方法存在被篡改数据量过大、无法确保知识产权数据安全性的问题,引入区块链与改进密文策略属性基加密(Ciphertext Policy Attribute Based Encryption,CP-ABE)算法,开展对知识产权数据防篡改方法的设计研究。首先,利用区...针对现有防篡改方法存在被篡改数据量过大、无法确保知识产权数据安全性的问题,引入区块链与改进密文策略属性基加密(Ciphertext Policy Attribute Based Encryption,CP-ABE)算法,开展对知识产权数据防篡改方法的设计研究。首先,利用区块链技术创建知识产权数据智能合约,避免非法攻击者对其进行篡改;其次,利用改进CP-ABE算法控制知识产权数据细粒度访问,实现知识产权数据加密防篡改与授权访问;最后,进行实验分析。实验结果表明,应用该方法能够有效控制知识产权数据被篡改量,有利于保障知识产权拥有者的个人权益。展开更多
结合云存储的应用环境,构造了一种基于密文策略属性的加密(ciphertext policy attribute based encryption,CP-ABE)技术和收敛加密技术的混合加密数据访问控制方案.该方案包括密钥发布中心、用户和云服务器三方实体,能高效、灵活、细粒...结合云存储的应用环境,构造了一种基于密文策略属性的加密(ciphertext policy attribute based encryption,CP-ABE)技术和收敛加密技术的混合加密数据访问控制方案.该方案包括密钥发布中心、用户和云服务器三方实体,能高效、灵活、细粒度地进行数据的访问控制,可提高云存储服务器的空间利用率,并使用签名技术支持数据源认证和数据完整性认证.理论分析与实验验证了该方案具有较高的实际应用价值.展开更多
密文策略属性基加密(ciphertext-policy attribute-based encryption,CP-ABE)技术可以在保证数据隐私性的同时提供细粒度访问控制.针对现有的基于CP-ABE的访问控制方案不能有效解决边缘计算环境中的关键数据安全问题,提出一种边缘计算...密文策略属性基加密(ciphertext-policy attribute-based encryption,CP-ABE)技术可以在保证数据隐私性的同时提供细粒度访问控制.针对现有的基于CP-ABE的访问控制方案不能有效解决边缘计算环境中的关键数据安全问题,提出一种边缘计算环境中基于区块链的轻量级密文访问控制方案(blockchain-based lightweight access control scheme over ciphertext in edge computing,BLAC).在BLAC中,设计了一种基于椭圆曲线密码的轻量级CP-ABE算法,使用快速的椭圆曲线标量乘法实现算法加解密功能,并将大部分加解密操作安全地转移,使得计算能力受限的用户设备在边缘服务器的协助下能够高效地完成密文数据的细粒度访问控制;同时,设计了一种基于区块链的分布式密钥管理方法,通过区块链使得多个边缘服务器能够协同地为用户分发私钥.安全性分析和性能评估表明BLAC能够保障数据机密性,抵抗共谋攻击,支持前向安全性,具有较高的用户端计算效率,以及较低的服务器端解密开销和存储开销.展开更多
文摘The cloud allows clients to store and share data.Depending on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved users.The user loses control of their data when the data is outsourced to the cloud.Therefore,access control mechanisms will become a significant challenging problem.The Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is an essential solution in which the user can control data access.CP-ABE encrypts the data under a limited access policy after the user sets some access policies.The user can decrypt the data if they satisfy the limited access policy.Although CP-ABE is an effective access control program,the privacy of the policy might be compromised by the attackers.Namely,the attackers can gather important information from plain text policy.To address this issue,the SHA-512 algorithm is presented to create a hash code for the user’s attributes in this paper.Depending on the created hash codes,an access policy will be formed.It leads to protecting the access policy against attacks.The effectiveness of the proposed scheme is assessed based on decryption time,private key generation time,ciphertext generation time,and data verification time.
基金Supported by the National Natural Science Foundation of China(61272488)Science and Technology on Information Assurance Laboratory(KJ-15-006)Fundamental and Frontier Technology Research of Henan Province(162300410192)
文摘In this paper, we present the first ciphertext-policy attribute-based encryption （CP-ABE） scheme for polynomial-size general circuits based on bilinear maps which is more suitable for practical use and more efficient than multilinear maps. Our scheme uses a top-down secret sharing and FANOUT gate to resist the ＂backtracking attack＂ which is the main barrier expending access tree to general circuit. In the standard model, selective security of our scheme is proved. Comparing with current scheme for general circuits from bilinear maps, our work is more efficient.
基金supported in part by the Nature Science Foundation of China (61472307, 61402112, 61100165, 61100231)Natural Science Basic Research Plan in Shaanxi Province of China (2016JM6004)
文摘For leakage-resilient ciphertext-policy attribute-based encryption （CP-ABE） at present, the size of the ciphertexts in most of them relies on the number of attributes. How to overcome this shortcoming is a challenge problem. Based on the Goldreich-Levin theorem and dual system encryption, an efficient CP-ABE scheme with constant size ciphertexts is proposed in this paper. It can tolerate leakage on master secret key and attribute-based secret keys with auxiliary inputs. Furthermore, the proposed scheme can be realized as resilience against continual leakage if keys are periodically updated. Under some static assumptions instead of other strong assumptions, the introduced scheme achieves adaptively security in the standard model.
文摘针对现有防篡改方法存在被篡改数据量过大、无法确保知识产权数据安全性的问题,引入区块链与改进密文策略属性基加密(Ciphertext Policy Attribute Based Encryption,CP-ABE)算法,开展对知识产权数据防篡改方法的设计研究。首先,利用区块链技术创建知识产权数据智能合约,避免非法攻击者对其进行篡改;其次,利用改进CP-ABE算法控制知识产权数据细粒度访问,实现知识产权数据加密防篡改与授权访问;最后,进行实验分析。实验结果表明,应用该方法能够有效控制知识产权数据被篡改量,有利于保障知识产权拥有者的个人权益。
文摘结合云存储的应用环境,构造了一种基于密文策略属性的加密(ciphertext policy attribute based encryption,CP-ABE)技术和收敛加密技术的混合加密数据访问控制方案.该方案包括密钥发布中心、用户和云服务器三方实体,能高效、灵活、细粒度地进行数据的访问控制,可提高云存储服务器的空间利用率,并使用签名技术支持数据源认证和数据完整性认证.理论分析与实验验证了该方案具有较高的实际应用价值.
文摘密文策略属性基加密(ciphertext-policy attribute-based encryption,CP-ABE)技术可以在保证数据隐私性的同时提供细粒度访问控制.针对现有的基于CP-ABE的访问控制方案不能有效解决边缘计算环境中的关键数据安全问题,提出一种边缘计算环境中基于区块链的轻量级密文访问控制方案(blockchain-based lightweight access control scheme over ciphertext in edge computing,BLAC).在BLAC中,设计了一种基于椭圆曲线密码的轻量级CP-ABE算法,使用快速的椭圆曲线标量乘法实现算法加解密功能,并将大部分加解密操作安全地转移,使得计算能力受限的用户设备在边缘服务器的协助下能够高效地完成密文数据的细粒度访问控制;同时,设计了一种基于区块链的分布式密钥管理方法,通过区块链使得多个边缘服务器能够协同地为用户分发私钥.安全性分析和性能评估表明BLAC能够保障数据机密性,抵抗共谋攻击,支持前向安全性,具有较高的用户端计算效率,以及较低的服务器端解密开销和存储开销.
